Upload
others
View
2
Download
0
Embed Size (px)
Citation preview
Timing and Location of Brain Areas Involved in Cognitive Theory of Mind in Children with Autism Spectrum Disorder
by
Veronica Wai-Jong Yuk
A thesis submitted in conformity with the requirements for the degree of Master of Arts in Psychology
Department of Psychology University of Toronto
© Copyright by Veronica Wai-Jong Yuk, 2015
ii
Timing and Location of Brain Areas Involved in Cognitive Theory
of Mind in Children with Autism Spectrum Disorder
Veronica Wai-Jong Yuk
Master of Arts in Psychology
Department of Psychology
University of Toronto
2015
Abstract
Cognitive theory of mind (ToM), or the ability to recognize the different mental states of others,
is a social cognitive skill that is often impaired in children with autism spectrum disorder (ASD).
This study enriches our understanding of ToM in ASD by using magnetoencephalography
(MEG) to determine the temporal properties of brain regions active during a false belief task, a
domain that has not been explored in this field, and yet is a significant component of brain
activity. We found that whereas typically-developing children activate familiar ToM regions,
such as the precuneus and the left temporoparietal junction, children with ASD appear to rely
more on working memory and inhibition regions, such as the right dorsal temporoparietal
junction and the right inferior frontal gyrus. This atypical activation suggests that children with
ASD make use of alternative strategies to compensate for their deficits in ToM.
iii
Acknowledgments
The path to scientific discovery is a long and arduous journey, in which no one person can travel
alone. Therefore, I would like to thank a number of people for their leadership and
companionship throughout this harrowing adventure.
First and foremost, I would like to thank my supervisor, Dr. Margot Taylor for all her
knowledge, guidance, and encouragement throughout this past year. Without her, this project and
thesis would not have been possible, and I would have never had the chance to work in such an
innovative field with the most wonderful people.
I would also like to express my gratitude to my committee members, Dr. Daphna Buchsbaum
and Dr. Evdokia Anagnostou, for their valuable comments and fresh perspectives.
I especially would like to thank Sarah Mossad, whose extensive knowledge and support were of
immense help to this project. Our countless hours spent analyzing data together in the lab were
much less agonizing because of her presence and good humour.
A very special thanks goes to Dr. Charline Urbain, whose boundless wisdom and expertise were
indispensable, and without whom I and countless others would still be lost.
I would further like to thank Anne Keller for her constant positivity and clever ideas, and for her
perseverance, despite all the setbacks we endured during analysis. Because of her, this project
and many others were able to move forward swiftly and efficiently.
I am also grateful to Dr. Elizabeth Pang, whose advice and encouragement were incredibly
helpful during challenging times.
Many thanks also go to Rachel Leung, MyLoi Huynh, Amanda Robertson, Marc Lalancette,
Tammy Rayner, and Ruth Weiss for all their assistance with testing participants and data
analysis. Rachel’s knowledge and experience with autism was particularly informative for this
thesis, and MyLoi and Amanda were a tremendous help in gathering data for this project.
I would also like to thank the rest of my colleagues, Julia Young, Vanessa Vogan, Wayne Lee,
Ben Morgan, and Ben Dunkley for all their constructive input and suggestions for this project.
iv
Finally, I would like to convey my deep appreciation for my friends and family. They saw me
through the worst and most stressful of times this past year, and I would have never been able to
accomplish this work without their constant encouragement and joy that they bring to my life.
v
Table of Contents
Acknowledgments .......................................................................................................................... iii
Table of Contents ............................................................................................................................ v
List of Tables ................................................................................................................................ vii
List of Figures .............................................................................................................................. viii
List of Appendices ......................................................................................................................... ix
Chapter 1 Introduction .................................................................................................................... 1
1.1 Behavioural Studies ............................................................................................................ 2
1.2 Neuroimaging Studies ......................................................................................................... 3
1.2.1 The Posterior Superior Temporal Sulcus ................................................................ 4
1.2.2 The Temporoparietal Junction ................................................................................ 4
1.2.3 The Medial Prefrontal Cortex ................................................................................. 7
1.2.4 Temporal Aspects of the Mentalizing Network ...................................................... 9
Chapter 2 Objectives and Hypotheses .......................................................................................... 11
Chapter 3 Methods ........................................................................................................................ 12
3.1 Participants ........................................................................................................................ 12
3.2 Neurocognitive Assessments and Questionnaires ............................................................ 12
3.3 Task ................................................................................................................................... 13
3.4 MEG Data Acquisition ..................................................................................................... 15
3.5 MRI Data Acquisition ....................................................................................................... 15
3.6 Analysis ............................................................................................................................. 16
3.6.1 Behavioural Data Analysis ................................................................................... 16
3.6.2 MEG Data Analysis .............................................................................................. 17
Chapter 4 Results .......................................................................................................................... 19
4.1 Assessments ...................................................................................................................... 19
vi
4.2 Task Performance ............................................................................................................. 21
4.3 Neuroimaging ................................................................................................................... 23
4.3.1 Within-group comparisons .................................................................................... 23
4.3.1.1 TD, FB > TB ......................................................................................................... 23
4.3.1.2 ASD, FB > TB ...................................................................................................... 24
4.3.2 Between-group comparisons ................................................................................. 25
4.3.2.1 TD > ASD, FB ...................................................................................................... 25
4.3.2.2 ASD > TD, FB ...................................................................................................... 25
Chapter 5 Discussion .................................................................................................................... 36
5.1 Performance on Neurocognitive and Behavioural Measures ............................................ 36
5.2 Timing and Location of Theory of Mind Regions in the Brain ........................................ 37
5.2.1 Timeline of Activation in TD Children ................................................................ 38
5.2.2 Timeline of Activation in Children with ASD ...................................................... 40
5.2.3 Typically-Developing Children Rely Mainly on ToM Regions for False-Belief
Processing, Whereas Children with ASD Additionally Use Working Memory
and Inhibition ........................................................................................................ 42
5.2.4 The Intersection between Theory of Mind and Working Memory ....................... 43
5.3 Summary ........................................................................................................................... 44
5.4 Limitations and Future Directions .................................................................................... 44
5.5 Conclusions ....................................................................................................................... 45
References ..................................................................................................................................... 46
Appendices .................................................................................................................................... 66
vii
List of Tables
Table 1: Scores on Neurocognitive Assessments and Questionnaires 21
Table 2: Coordinates of Significant Peaks of Brain Activation of Interest in TD Children and
Children with ASD in the False-Belief Task 27
viii
List of Figures
Figure 1: The stimuli for the false belief task. 14
Figure 2: Boxplots illustrating the scores of the TD and ASD group on the neurocognitive
assessments. 20
Figure 3: Boxplots demonstrating how participants were rated on the parent questionnaires. 21
Figure 4: Boxplots comparing accuracy and reaction time on the FB and TB trials of the false-
belief task. 22
Figure 5: Timeline of brain activation for TD and ASD groups in response to the false-belief
task 33
ix
List of Appendices
Supplementary Figure 1: Glass brain images that depict areas that are and are not preserved in
the TD to ASD group comparison of false belief when
controlling for working memory load. 66
1
Chapter 1 Introduction
Theory of mind (ToM) was first defined by Premack and Woodruff (1978) as the ability to
attribute mental states to others, or the understanding that others may have thoughts, feelings,
and perspectives independent from our own. Though Premack and Woodruff’s (1978) work
concerned chimpanzees, their concept was extended to humans by Baron-Cohen, Leslie, and
Frith (1985), who proposed that a lack or impairment of ToM may be the cause of some of the
social deficits characteristic of autism spectrum disorder (ASD). Baron-Cohen (1988) also later
suggested that ToM may consist of two components: cognitive and affective. Cognitive ToM
refers to the recognition that everyone possesses separate mental states, whereas affective ToM is
more specifically concerned with the knowledge that others may feel differently than oneself in a
given situation (Baron-Cohen, 1988).
Although advances in neuroimaging in the past few decades have allowed researchers to probe
the brain areas underlying cognitive and affective ToM (Shamay-Tsoory, Tomer, Berger,
Goldsher, & Aharon-Peretz, 2005; Kalbe et al., 2010; Nandrino et al., 2014), relatively few
neuroimaging studies have looked at ToM in the ASD population, who consistently show deficits
in ToM (Baron-Cohen et al., 1985; Perner et al., 1989; Buitelaar, van der Wees, Swaab-
Barneveld, & van der Gaag, 1999; Beaumont & Newcombe, 2006; Matthews et al., 2012), and
even fewer have looked specifically at cognitive ToM in those with ASD, which may underlie
affective ToM abilities. While research in this field has focused mainly on locations of brain
activation (Happé et al., 1996; Vaidya et al., 2011; Lombardo, Chakrabarti, Bullmore, MRC
AIMS Consortium, & Baron-Cohen, 2011; von dem Hagen, Stoyanova, Rowe, Baron-Cohen, &
Calder, 2014), none has explored their timing in ASD; it has only been described in typically-
developing (TD) children (Sabbagh & Taylor, 2000; Vistoli, Brunet-Gouet, Baup-Bobin, Hardy-
Bayle, & Passerieux, 2011). While the specific areas involved in cognitive ToM in ASD are
extremely important to establish, timing information is equally as meaningful, since the
behavioural impairments seen in those with ASD may arise from both temporal and spatial
abnormalities in neural activation. Moreover, it is important to describe such differences in brain
activity during development as children and adolescents with ASD have also been shown to
recruit different brain regions in a variety of situations, compared to their TD peers (Leung et al.,
2
2014; Solomon et al., 2014; Doyle-Thomas et al., 2015), and any form of atypical brain activity
during childhood may affect the groundwork for behaviours exhibited in adulthood.
Given the importance of the temporal aspect of brain activation, this study investigated
differences in both timing and location of brain areas activated in children with ASD during a
false-belief task, a test often used to assess cognitive ToM abilities (Wellman, Cross, & Watson,
2001; Gweon & Saxe, 2013), using magnetoencephalography (MEG), a neuroimaging technique
that provides sensitive temporal and spatial measures of brain activity (Hari & Salmelin, 2012).
With the knowledge gained from this study, we can extend the current behavioural and
neuroimaging literature on cognitive ToM in children with ASD into the temporal domain,
allowing us to better characterize ToM deficits in the ASD population, which in turn will be
informative for designing, enhancing, and monitoring interventions to improve social outcomes
in children with ASD.
As the remainder of this work will mainly focus on cognitive ToM, the term ToM will
henceforth refer simply to the cognitive domain, unless otherwise specified.
1.1 Behavioural Studies
Behavioural studies investigating ToM in ASD began with Baron-Cohen et al.’s (1985) seminal
study, where they compared the performance of children with ASD to that of children with
Down’s syndrome and TD children on a classic false-belief ToM task, the Sally-Anne task. In
this task, Sally puts a marble in her basket. Sally leaves, and Anne moves the marble from the
basket to a box. The participant must then answer where Sally will look for her marble. While
the majority of Down’s syndrome and TD children passed the ToM task, a significant majority of
children with ASD failed the task (Baron-Cohen et al., 1985), signifying some fundamental
difference in ToM processing in ASD. In fact, this discrepancy in performance in these ToM
tasks may be not only due to a deficit, but also due to a delay in ToM ability acquisition (Baron-
Cohen, 1991; Sparrevohn & Howie, 1995; Serra, Loth, van Geert, Hurkens, & Minderaa, 2002).
It has been suggested that verbal ability in those with ASD is related to ToM aptitude, such that
an individual with ASD who has a high verbal age generally will do better on tests of ToM than
one who has a low verbal age (Happé, 1995; Sparrevohn & Howie, 1995; Steele, Joseph, &
Tager-Flusberg, 2003). However, because these studies linking verbal and ToM abilities are all
3
correlational, it is also equally likely that in addition to verbal abilities potentiating ToM
abilities, it may be that being able to apply ToM can also lead to improved verbal abilities in
children with ASD, suggesting a bidirectional relationship between the two (de Villiers, 2007).
For instance, Capps et al. (2000) found that while children with ASD and children with
developmental delays, who were matched for language ability, both had difficulties
understanding a narration, only in children with ASD were narrative abilities correlated with
ToM abilities. Furthermore, a number of studies have shown that individuals with ASD have
difficulties understanding pragmatic language, even though they have normal language abilities
(Martin & McDonald, 2004; Hale & Tager-Flusberg, 2005; Colle, Baron-Cohen, Wheelwright,
& van der Lely, 2008; Li, Law, Lam, & To, 2013).
An alternative explanation for the ToM deficits seen in ASD is that poor social motivation may
lead to a poor understanding of others’ mental states. There has been substantial research into the
lack of social motivation observed in those with ASD (Demurie, Roeyers, Baeyens, & Sonuga-
Barke, 2011; Chevallier, Grezes, Molesworth, Berthoz, & Happe, 2012; Stavropoulos & Carver,
2014; Wang et al., 2014) and how it may affect their cognitive development (Klintwall, Macari,
Eikeseth, & Chawarska, 2014; Vivanti, Trembath, & Dissanayake, 2014). Chevallier, Kohls,
Troiani, Brodkin, and Schultz (2012) make a persuasive argument that low social motivation
may lead specifically to social cognitive (i.e. ToM) deficits in individuals with ASD, in that
diminished social motivation manifests as a reduced desire to seek out social situations, resulting
in less practice processing social stimuli, which in turn leaves social cognitive abilities under-
developed. However, few studies have explored this hypothesis by directly comparing level of
social motivation to ToM abilities (Assaf et al., 2013), an avenue that may be worth pursuing to
explain ToM deficits in those with ASD.
1.2 Neuroimaging Studies
In order to comprehend the basis of these impairments in ToM in ASD, researchers investigating
ToM in TD individuals have identified a constellation of brain areas consistently activated
during a variety of ToM tasks, known collectively as the mentalizing network. This network
includes the precuneus/paracingulate cortex (Walter et al., 2004; Hervé, Razafimandimby,
Jobard, & Tzourio-Mazoyer, 2013), the temporal poles (Olson, Plotzker, & Ezzyat, 2007;
Reniers, Völlm, Elliott, & Corcoran, 2014), and, most importantly, the posterior superior
4
temporal sulcus (pSTS), the temporoparietal junction (TPJ), and the medial prefrontal cortex
(mPFC) (Gallagher & Frith, 2003; Carrington & Bailey, 2009; Dodell-Feder, Koster-Hale,
Badny, & Saxe, 2011).
1.2.1 The Posterior Superior Temporal Sulcus
The pSTS is involved in processing biological motion (Allison, Puce, & McCarthy, 2000;
Pelphrey et al., 2003; Herrington, Nymberg, & Schultz, 2011; Dayan et al., 2014). This function
may explain its role in perceiving or rationalizing the actions of others (Grezes, Frith, &
Passingham, 2004; Fukui et al., 2006; Wyk, Hudac, Carter, Sobel, & Pelphrey, 2009), as
people’s intentions are not always clear. Interestingly, Materna, Dicke, and Their (2008) found
that the pSTS was similarly activated during two social communicative gestures, a directed eye
gaze and a finger point toward a stimulus. Considering that individuals with ASD typically have
difficulties with following another’s eye gaze (Richler & Coss, 1976; Baron-Cohen, Baldwin, &
Crowson, 1997; Leekam, Hunnisett, & Moore, 1998), it is possible that they have a deficiency in
the pSTS, which might also lead to issues with other social communicative actions.
This idea is supported by both a behavioural study by Camaioni, Perucchini, Muratori, Parrini,
and Cesari (2003), which showed that young children with ASD failed to understand experience-
sharing pointing (as opposed to pointing to simply request something), and by an fMRI study by
Vaidya et al. (2011), which demonstrated that the pSTS was active for arrows (non-social
stimuli) that were used to direct attention, but not for gazes (social stimuli), whereas in TD
children, the opposite pattern of pSTS activation was observed. These findings are in line with a
recent EEG study by Stavropoulos and Carver (2014), who found that although children with
ASD processed rewards accompanied by non-social stimuli normally, they had reduced
responses to those accompanied by social stimuli.
1.2.2 The Temporoparietal Junction
Although the TPJ is adjacent to the pSTS, they have fairly unique functions. Gobbini, Koralek,
Bryan, Montgomery, and Haxby (2007) proposed that the pSTS is involved in interpreting
actions and biological movements, whereas the TPJ deals more with mentalizing in a false belief
scenario. The significance of the TPJ in ToM was brought to prominence in a paper by Saxe and
Wexler (2005), who showed that the right TPJ was specifically involved in attributing
5
behaviours to people, in that if a behaviour or mental state of a person was incongruent with their
previously described character, right TPJ activity would increase.
However, there is some uncertainty in the literature as to whether the left, right, or bilateral TPJ
is crucial for ToM reasoning. To date, few studies have shown that only the left TPJ is necessary
for ToM reasoning (Samson, Apperly, Chiavarino, & Humphreys, 2004). In a study by
Bahnemann, Dziobek, Prehn, Wolf, and Heekeren (2010), the left TPJ, but not the right TPJ, was
activated during a ToM task, where participants were asked to make a judgment on a character’s
mental state. They also found activity in the right TPJ, but it was correlated more with a moral
judgment task, where participants were asked to determine the congruency of a character’s
actions to their mental state, which may explain why the previous study by Saxe and Wexler
(2005) only found activity in the right TPJ and not the left. A meta-analysis by Schurz,
Aichhorn, Martin, and Perner (2013) found that the left TPJ, in addition to the left middle
occipital gyrus and precuneus, were all implicated in two important ToM processes, false belief
and visual perspective taking, but not the right TPJ.
In contrast, Rabin et al. (2010) found that while autobiographical memory and ToM processing
networks have some overlap, the right TPJ was exclusively activated in the ToM task. Similarly,
Mitchell (2008) observed that both an attentional and ToM task activated similar regions of the
right TPJ, prompting Scholz, Triantafyllou, Whitfield-Gabrieli, Brown, and Saxe (2009) to
respond with an experiment showing that they actually activate distinct areas in the right TPJ.
Despite these findings, one cannot ignore the number of studies that show bilateral activation of
the TPJ during ToM tasks, compared to unilateral activation (Rothmayr et al., 2011; Young,
Scholz, & Saxe, 2011; van Veluw & Chance, 2014). One study by Saxe and Powell (2006)
showed that both the left and right TPJ responded to stories about a character’s thoughts, but not
to stories about one’s internal state. In another experiment by Kobayashi, Glover, and Temple
(2007), the bilateral TPJ responded to both verbal and non-verbal false belief tasks in both TD
children and adults.
To clarify these seemingly disparate findings, Aichhorn et al., 2009 sought to elucidate the
specific roles of the left and right TPJ in ToM by comparing brain activation in TD individuals
on a variety of mentalizing tasks. They found that the left TPJ responded to false belief and false
sign tasks, whereas the right TPJ was activated by both true and false belief stories, which points
6
toward the left TPJ playing a role in incongruence detection, and the right TPJ in mentalizing
about others’ beliefs. These results appear to be contradictory to the studies mentioned above,
but it may be due to the fact that, for example, Bahnemann et al. (2010) used emotionally-
valenced stimuli (e.g. one character punching another), and so the emotional processes involved
interacted with and altered activity in the left and right TPJ.
In the ASD population, the TPJ often shows less or atypical activation in tasks involving ToM,
especially in the right TPJ. In an experiment by Williams et al. (2006), they found that
adolescents with ASD had greater activation in the right TPJ during action observation as
opposed to imitation, whereas TD adolescents showed the opposite. This inverse in function,
combined with the evidence that the pSTS is associated with understanding actions, illustrates
the likelihood of some dysfunction in the mentalizing network in those with ASD, where perhaps
the TPJ takes over the role of an impaired pSTS.
Children with ASD appear to have structural abnormalities that contribute to their deficits, in
addition to functional ones. In a study comparing grey matter differences between ASD,
attention deficit/hyperactivity disorder (ADHD), and control children and adolescents, the
participants with ASD had grey-matter abnormalities near the right TPJ, compared to the other
two groups (Brieber et al., 2007). These findings do not necessarily indicate that ToM deficits in
the ASD population are caused by an abnormal TPJ, since individuals with ADHD have also
been shown to have ToM difficulties (Buitelaar et al., 1999; Caillies, Bertot, Motte, Raynaud, &
Abely, 2014). This does not absolutely rule out the possibility of a dysfunctional TPJ, either, as it
is possible that those with ADHD have deficits elsewhere that lead to their ToM impairments.
Another study by Lombardo et al. (2011) noticed that in control adults, the right TPJ was
selectively active for mentalizing versus observing physical events, but in adults with ASD, the
right TPJ was active for both conditions, even when mentalizing about the self and others, and it
was less active overall than in controls. Moreover, this activation was negatively correlated with
social impairment symptom severity seen in the ASD group. A recent study by Kana, Libero,
Hu, Deshpande, and Colburn (2014) found similar results, where the ASD group recruited the
bilateral TPJ during a task where they had to determine the intentions of a character, although the
activation was weaker than in controls. This lower activation was paralleled by significantly
worse behavioural performance on the intentionality task. Taken together, these studies
7
demonstrate that impairments in the activation and recruitment of the TPJ are likely associated
with ToM deficits in ASD.
1.2.3 The Medial Prefrontal Cortex
An important component of the mentalizing network is the mPFC, and its contribution to ToM
abilities has been extensively studied. In one experiment, participants were asked to imagine
meeting a stranger and invent a narrative about their mental state, which instigated mPFC
activation (Calarge, Andreasen, & O’Leary, 2003). Saxe and Powell (2006) found that the mPFC
was activated similarly in three different tasks where they read about a character’s thoughts,
personal thoughts, or social information about a person, indicating that the mPFC may be a hub
for various social cognitive functions. These effects in mPFC were not limited to verbal
processes, as comparable results were found in non-verbal cartoon tasks looking at ToM
(Gallagher et al., 2000; Rothmayr et al., 2011). There is also some indication that the mPFC may
have distinct regions that subserve unique functions, as a recent study by Hartwright, Apperly,
and Hansen (2014) found that during a ToM task, the dorsal mPFC was related to the cognitive
load or demand, while the rostral mPFC was correlated with reasoning about the intentions of a
person. In addition to these two areas, the posterior mPFC has been shown to be causally related
to discriminating between the differing perspectives of others and oneself using repetitive
transcranial magnetic stimulation (rTMS), which is able to temporarily inhibit activity in a
specific area of the brain (Schuwerk et al., 2014). Considering that, as described previously,
Lombardo et al. (2011) found right TPJ activation for both self and other mentalizing in adults
with ASD, these findings suggest that the right TPJ and posterior mPFC may be functionally
connected, such that both areas depend on each other to separate one’s own thoughts from the
potentially dissimilar thoughts of others.
Lesion studies have also provided evidence for the mPFC’s significance in the mentalizing
network. Damage to the mPFC was associated with poor performance on more challenging ToM
tasks, such as deception (Stuss, Gallup Jr., & Alexander, 2001) and social faux pas (Stone,
Baron-Cohen, & Knight, 1998). A case study, however, described a patient with a large bilateral
mPFC lesion, covering areas implicated in previous studies of ToM, who had no impairments on
a wide range of ToM tasks, including the social faux pas task mentioned above (Bird, Castelli,
Malik, Frith, & Husain, 2004). These authors suggested that if, in fact, mPFC is involved in ToM
8
reasoning, then it may be the case that in older adults (as the patient was 62 at the time of her
infarction), the functions of the mPFC can be performed in another region of the mentalizing
network. This hypothesis is somewhat supported by a study by Moriguchi, Ohnishi, Mori,
Matsuda, and Komaki (2007), where the location of the peak of activation in the mPFC was
correlated with the age of the participant, such that in younger children, a ToM task activated
more ventral parts of the mPFC, and in the older children, activation was observed in more
dorsal parts of the mPFC, indicating that development plays a role in the site of mPFC activity
associated with ToM. However, since most studies investigating ToM development focus on
childhood rather than increasing age groups, it is difficult to say whether these changes in
location occur throughout the lifespan.
In ASD, issues with ToM have also been related to dysfunction in the mPFC. Early work by
Happe et al. (1996) indicated that while controls activated the left mPFC during a ToM task
where they were asked to think about why a character acted in a certain way, individuals with
Asperger’s syndrome exhibited no such activation for the same task. Marsh and Hamilton (2011)
showed that during a hand movement comprehension task, adults with ASD had no difference in
activation in the mPFC between a rational and an irrational hand movement, whereas the mPFC
had a greater response to an irrational hand movement in controls. In the language processing
domain, Colich et al. (2012) found that even though children and adolescents with and without
ASD were able to interpret and discriminate between ironic and sincere remarks, those without
ASD only activated left-lateralized language areas, while those with ASD recruited bilateral
language and mentalizing brain areas, which the authors attributed as compensatory mechanisms.
Thus, these findings in the ASD population complement the TD literature on the role of the
mPFC, and it appears that this brain region may be involved in interpreting the meaning behind
one’s actions by integrating information about another’s mental state.
Although most of the studies mentioned above found differences in only one of the regions of the
mentalizing network, there are a great number of studies showing activation of a combination of
these areas during ToM tasks. For instance, Dodell-Feder et al. (2011) and Dufour et al. (2014)
found that the pSTS, TPJ, and mPFC all responded consistently to stories involving false belief.
von dem Hagen et al. (2014) found similar results, where a direct gaze, which may prompt
automatic mental state processes, led to activation of the pSTS, TPJ, and mPFC in controls,
whereas these same areas were activated only when individuals with ASD looked at a face with
9
an averted gaze. These three areas were also found to be less functionally correlated in the ASD
group than in controls.
A number of studies have outlined the different functions of these areas by comparing their
activity in a variety of ToM tasks. Ciaramidaro et al. (2007) differentiated between the functions
of the left TPJ, the right TPJ, and the mPFC by showing that the right TPJ was involved mainly
in processing intentions, while the left TPJ and the mPFC were responsible for understanding
intentions. Vistoli et al. (2011) found that the left TPJ and pSTS perceive social cues, while the
right TPJ and pSTS recognize intentions. Also, Murdaugh, Nadendla, and Kana (2014) observed
that although both the TPJ and the mPFC were activated when thinking about the intentions of
others in a sequence of actions, the TPJ was more strongly correlated with the rest of the
mentalizing network. This suggests that the TPJ may play a more central role to ToM processing,
which is supported by another finding in their study that showed individuals with ASD had lower
functional connectivity in the mentalizing network, especially in the TPJ.
1.2.4 Temporal Aspects of the Mentalizing Network
The majority of temporal information regarding ToM-related brain activity has been determined
through electroencephalography (EEG) studies in adults. Sabbagh and Taylor (2000) were the
first to report the timing of brain activity during a false belief task, where left frontal areas
showed greater positive activity between 300-400 ms, and left parietal areas had more negative
activity between 600-840 ms. In a later study, Sabbagh, Apperly, Chiavarino, and Humphreys
(2004) asked participants to ascertain a person’s mental state based solely on the expression in
their eyes, and they found a negative EEG component from 270-400 ms in the orbitofrontal and
medial temporal regions, which may correspond to the activity seen in the mPFC in fMRI studies
(Gallagher & Frith, 2003). Similarly, using a mental reasoning task, where participants had to
predict which action a character would take based on what they were told of the character’s
mental state, Cao, Li, Li, and Li (2012) reported that the second negative EEG component in the
prefrontal cortex elicited by this task was both earlier and smaller between 240-440 ms than in
tasks that did not require reasoning about mental states. A study by McCleery, Surtees, Graham,
Richards, and Apperly (2011) found that a positive EEG component localized to the TPJ,
normally peaking around 450 ms, exhibited longer, sustained activity when participants were
10
asked to take the perspective of another person, especially when the other person’s perspective
was inconsistent with their own.
These results are supported by studies using MEG, which has a much better spatial resolution
than EEG (Anninos, Anogianakis, Lehnertz, Pantev, & Hoke, 1987). For instance, Pylkkanen
and McElree (2007) contrasted neural responses to sentences with implied meanings to those
with explicit meanings using MEG, and they observed that only the sentences with implied
connotations activated the ventral mPFC between 350-450 ms. In addition, Vistoli et al. (2011)
found that the right TPJ, right STS, and right inferior parietal cortex were recruited from 200-600
ms during an attribution of intentions task.
As mentioned above, there have been no studies as of yet that have analyzed the temporal
relationship between areas activated by tasks involving ToM in the ASD population. Only one
study by Hasegawa et al. (2013) has attempted to do so by connecting ToM-related brain activity
to Autism Quotient (AQ) scores in TD adults. They found that direct gaze elicited greater
activity in the right pSTS between 150-250 ms, and this activity positively correlated with AQ
scores. However, these results cannot be generalized to the ASD population, as children with
ASD undergo atypical neural development (Fishman, Keown, Lincoln, Pineda, & Müller, 2014;
Leung, Ye, Wong, Taylor, & Doesburg, 2014; Orekhova et al., 2014; Vogan et al., 2014), and so
replication with a clinically-diagnosed ASD sample is necessary to validate these results.
Although the roles of the pSTS, TPJ, and mPFC are not clearly defined, the existing literature
suggests that the pSTS is involved in processing and understanding biological motion, that the
TPJ may be responsible for processing actions and their intentions, and that the mPFC may be
implicated in understanding the intentions of social actions. It is impossible to sketch a complete
profile of the functions of these areas, though, without crucial timing information. While EEG
and MEG studies have shown that these regions are involved in fairly early neural processing
steps, generally between 200-400 ms post-stimulus, these results have yet to be consistently
reproduced and supported by separate studies.
11
Chapter 2 Objectives and Hypotheses
This study will add to our present knowledge of the timing of brain areas in the mentalizing
network by providing fundamental temporal and spatial information of brain areas activated
during a ToM task in children with ASD, which is a group that reliably shows ToM deficits
(Baron-Cohen et al., 1985; Happe, 1995; Buitelaar et al., 1999; Matthews et al., 2012), but for
which no timing information regarding brain activity during ToM processing has been reported.
We tested ToM abilities in two groups of children, those with ASD and those without (TD),
using a false-belief task similar to the classic Sally-Anne task (Baron-Cohen et al., 1985). To
capture the information on timing and location simultaneously, we recorded the children’s brain
activity as they did the task using MEG, which detects weak magnetic fields emitted from
neuronal activity with a temporal resolution of 1 ms and spatial resolution of 3 mm (Hari &
Salmelin, 2012). In response to the false-belief situations, we hypothesized that the TD children
would recruit the pSTS, TPJ, and mPFC, while the children with ASD would recruit only the
pSTS and the TPJ, though to a lesser degree, and they would draw on additional brain regions to
adjust for their impairments in ToM processing. With regards to timing, we predicted that, based
on the hierarchy of complexity of these areas, the pSTS would be involved in early (~200-300
ms) ToM processing, while the TPJ and mPFC would be associated with later ToM processes
(~300-400 ms and 400-500 ms post-stimulus, respectively) in TD children, but the children with
ASD would show a disordered and delayed temporal relation in the brain areas they recruit.
12
Chapter 3 Methods
3.1 Participants
For this study, 44 typically-developing (TD) participants and 34 participants with high-
functioning autism spectrum disorder (ASD) between the ages of 8 and 12 were recruited. Of
these participants, 11 TD and 15 children with ASD were not included in the analyses due to
incompatibility with the MEG scanner (i.e. noise due to metal artefacts), excessive movement,
and poor (≤ 50%) performance on the task. Participants were then matched for age and sex,
resulting in a sample of 22 TD children (19 males, 10.34 ± 1.32 years old) and 19 children with
ASD (16 males, 10.52 ± 1.45 years old). All participants were screened for low IQ (< 70) and
premature birth, and TD participants were not included if they reported any history of
psychological, neurological, or developmental disorders. Participants with ASD were not
excluded if they presented with comorbid disorders, although a primary diagnosis of ASD was
confirmed with a combination of expert clinical judgement and the Autism Diagnostic
Observation Schedule, Generic (ADOS-G; Lord et al., 2000) or Second Edition (ADOS-2; Lord
et al., 2012). Three children with ASD were each taking psychotropic medication at the time of
scanning, specifically Prozac and Concerta. Informed assent was given by all children, and
informed consent was obtained from their parents. All aspects of testing, including informed
consent, cognitive testing, and MEG and MRI scanning, took place at the Hospital for Sick
Children in Toronto, Canada. This study was approved by the Research Ethics Board at the
Hospital for Sick Children.
3.2 Neurocognitive Assessments and Questionnaires
A battery of neurocognitive tests was administered to all children to assess their general
executive functioning and cognitive skills. The two-subtest version of the Weschler Abbreviated
Scale of Intelligence, Second Edition (WASI-II; Weschler, 2002), which includes the
Vocabulary and Matrix Reasoning subtests, was used as an estimate of IQ. The Forward and
Backward Digit Recall subtests of the Working Memory Test Battery for Children (WMTB-C;
Pickering & Gathercole, 2001) were administered to detect working memory differences
between the two groups. Two subtests of the Developmental Neuropsychological Assessment,
13
Second Edition (NEPSY-II; Korkman, Kirk, & Kemp, 2007), namely Inhibition and Theory of
Mind, were also used to assess their respective titular cognitive domains.
Parents completed two questionnaires regarding their child’s executive functioning and social
behaviour: the Behavior Rating Inventory of Executive Function (BRIEF; Gioia, Isquith, Guy, &
Kentworthy, 2000) and the Social Responsiveness Scale, First (SRS; Constantino & Gruber,
2005) and Second Edition (SRS-2; Constantino & Gruber, 2012).
3.3 Task
Participants completed a nonverbal (picture based) false-belief task (Figure 1A) modelled after
the task used by Dennis et al. (2012) and adapted for the MEG scanner. In each trial, children
saw two consecutively presented visual stimuli, in which there are two characters, Jack and Jill.
In the first picture, Jack is holding a ball over one of two hats, and Jill is present and watching
him. The first picture was then replaced by the second one, where one of four scenarios was
presented: (1) Witnessed-Unswitched, where Jill watches (Witnessed) as Jack puts the ball in the
same hat he was holding it over in the first picture (Unswitched); (2) Witnessed-Switched, where
Jill watches (Witnessed) as Jack changes his mind and puts the ball in the other hat (Switched);
(3) Unwitnessed-Unswitched, where Jill goes away (Unwitnessed), and then Jack puts the ball in
the same hat (Unswitched); and (4) Unwitnessed-Switched, where Jill goes away (Unwitnessed),
and then Jack changes his mind and puts the ball in the other hat (Switched). The first three
conditions – Witnessed-Unswitched, Witnessed-Switched, and Unwitnessed-Unswitched – each
represented a true belief, as Jill would know the correct location of the ball in all these
conditions, whereas the other condition – Unwitnessed-Switched – represented a false belief,
since Jill would be mistaken as to the ball’s location, as Jack switched the ball without Jill’s
knowledge. The participants were asked to indicate, using a button box, in which one of the two
hats Jill thinks the ball is. They then received feedback on their response, either a green
checkmark for a correct answer or a red cross for an incorrect answer.
All children were given a short practice session outside of the MEG scanner to familiarize them
with the task. During the practice session, the experimenter explained the four different
conditions of the task and gave detailed feedback if the child did not understand parts of the task.
The practice session ended when the child was able to correctly answer the trials and verbally
indicated that they understood the requirements of the task.
14
True Belief False Belief
Witnessed-Unswitched Witnessed-Switched Unwitnessed-Unswitched Unwitnessed-Switched
A
B
Figure 1 - The stimuli for the false belief task, which were adapted from Dennis et al. (2012). (A) An example of
the four different types of trials in this task: Witnessed-Unswitched, Witnessed-Switched, Unwitnessed-
Unswitched, and Unwitnessed-Switched. The first three conditions tested true belief abilities, while the
Unwitnessed-Switched condition assessed false belief. Subsequent analyses focused on the Witnessed-Switched
and Unwitnessed-Switched conditions, outlined in green and red above. (B) The timing of the stimuli in the task.
The first picture of each trial appeared for 500 ms, followed by the second stimulus, which was shown for up to
3000 ms or until the child responded, whichever came first. After the response, feedback in the form of a green
checkmark or red cross appeared for 1000 ± 100ms, and the next trial began immediately after.
15
The participants then went into the magnetically-shielded room, where they performed the task
while lying supine in the MEG scanner. The stimuli for the task were presented using
Presentation 0.70 (Neurobehavioral Systems, 2014) and back-projected onto a screen at a
distance of 79 cm from their eyes. A photodiode attached to the screen was used to precisely
detect stimulus onset time. Each trial began with the presentation of the first stimulus for 500 ms,
then the second picture for a maximum of 3000 ms, or until the child responded, followed by
feedback for the trial, which was displayed for 1000 ms with a jitter of ± 100 ms (Figure 1B).
The task was designed such that the ball was put into each of the hats an equal number of times,
although in two-thirds of the trials, the ball’s position was switched from its initial position, and
in the remaining one-third, it was not switched. Additionally, in half the trials, Jill was present,
and in the other half, she was not. The trials were arranged in this way to capture more of the
Unwitnessed-Switched and Witnessed-Switched trials, as they were our two main conditions of
interest, without alerting the participants to this fact. The task ended when either the child
correctly completed a total of 300 trials over the four conditions (100 Unwitnessed-Switched,
100 Witnessed-Switched, 50 Unwitnessed-Unswitched, and 50 Witnessed-Unswitched), or after
15 minutes had passed, whichever came first. The participants’ responses and their latencies
were recorded with their MEG data.
3.4 MEG Data Acquisition
A CTF MEG system consisting of 151 axial gradiometers (MISL, Coquitlam, British Columbia,
Canada) was used to acquire the MEG data. Fiducial coils were placed on three reference points
– the nasion, and the left and right pre-auricular points – on each participant to track head
position. Children lay supine with only their head in the MEG dewar, during which time they
performed the task described above. Data were sampled at 600 Hz with continuous head
localization. To optimize the signal-to-noise ratio, a third-order spatial gradient was used, and the
signal was bandpassed from 0-150 Hz.
3.5 MRI Data Acquisition
A 3.0 T MRI scanner (MAGNETOM Tim Trio, Siemens AG, Erlangen, Germany) with a 12-
channel head coil in the Hospital for Sick Children was used to acquire anatomical MRIs to
allow accurate determination of sources of MEG activity. Radio-opaque markers were placed in
16
the same locations as the fiducial coils used in the MEG scan to ensure accurate MEG-MRI co-
registration. Participants completed a T1-weighted MRI scan using the 3D SAG MPRAGE
sequence with the following parameters: GRAPPA = 2, TR/TE/FA = 2300ms/2.96ms/90°, FOV
= 28.8 × 19.2cm, 256 × 256 matrix, 192 slices, slice thickness = 1.0mm isotropic voxels.
3.6 Analysis
3.6.1 Behavioural Data Analysis
Scores on the neurocognitive assessments and questionnaires, as well as the participants’
response times and accuracy on the task, were analyzed using R 3.1.2 (R Core Team, 2014). A
chi-square test and a t-test were performed to confirm homogeneity between the TD and ASD
groups with regards to sex and age, respectively. These tests revealed no difference in sex (Χ2 =
0, p = 1) or age (t(39) = 0.42, p = 0.67). T-tests were also used to compare the scores of the two
groups on each of the neurocognitive assessments and questionnaires. For the WASI-II, IQ was
used as an indicator of their performance on this test, as it is a classical measure of intelligence.
Composite scores that were created from the sum of the scaled scores of the Forward and
Backward Digit Recall tests of the WMTB-C were used for analysis, as we were interested in
differences in their general working memory abilities and not on their success on each of these
subtests. On the NEPSY-II Inhibition subtest, differences on the Inhibition vs. Naming scaled
score were examined, rather than the simple Inhibition scaled score, as we believed the Inhibition
vs. Naming score is a better measure of inhibition skills, since it is not confounded by their
ability to name the objects in the test. The total raw scores on the NEPSY-II Theory of Mind
subtest were contrasted as the NEPSY-II does not provide age-adjusted standard scores for this
subtest. However, the TD and ASD groups were age-matched, so their raw scores could be
directly compared. For the BRIEF and the SRS and SRS-2, their total scaled scores (the Global
Executive Composite (GEC) score for the BRIEF, and the Total Score for the SRS and SRS-2)
were analyzed to evaluate how the children were scored by their parents on these questionnaires.
Linear mixed-effects models were fit to determine differences in response time and accuracy on
the task, with group (TD or ASD), switching (Switched or Unswitched), and witnessing
(Witnessed or Unwitnessed) as predictors, and IQ as a covariate. Main effects of group,
switching, witnessing, and IQ were included in the analysis, as well as the interactions between
group and switching, group and witnessing, switching and witnessing, and group and IQ. To
17
account for the repeated measurement of each participant over the different conditions,
participants were included as random effects. Thus, the models constructed were as follows:
response time ~ group * switching * witnessing + group * IQ + (1 | participant)
accuracy ~ group * switching * witnessing + group * IQ + (1 | participant)
As mentioned above, our analyses focused mainly on differences between the Unwitnessed-
Switched and Witnessed-Switched conditions. We chose these two conditions for all our
analyses as they reflected the differences between false and true beliefs most clearly, with Jill’s
absence or presence indicating the generation of a false or true belief, respectively, while
controlling for participants’ understanding of switching the ball’s position. Therefore, although
our task paradigm contains three different true belief scenarios, only the Witnessed-Switched
condition will hereafter be referred to as the true belief (TB) condition, and the Unwitnessed-
Switched condition as the false belief (FB) condition.
3.6.2 MEG Data Analysis
MEG data were analyzed in MATLAB 2014b (The MathWorks, 2014) with customized scripts
that made use of SPM12 software (FIL Methods Group, 2014). Data were filtered from 1-50 Hz
with a fifth-order Butterworth bandpass filter. Trials were epoched from -200 to 600 ms relative
to the presentation of the second picture stimulus and subsequently baseline corrected. Head
motion artefacts were controlled by discarding trials in which the participant moved 5 mm within
the trial or 10 mm between trials. Independent component analysis (ICA) as implemented by
FieldTrip (Oostenveld, Fries, Maris, & Schoffelen, 2011) was used to detect and remove
heartbeat and eyeblink artefacts in the data. Artefacts were further removed from the data by
rejecting trials in which the signal exceeded 2500 fT at any of the channels, and by excluding
MEG channels in which more than 20% of trials surpassed this threshold. Data were then
averaged across trials for each condition and each participant.
Coregistration of MEG data and corresponding anatomical MRIs was done for each individual
based on the three reference points (fiducials) mentioned above. The forward model was
calculated based on the single-shell model for computing the lead field matrix (Nolte, 2003), and
the inverse model was generated using the minimum norm estimation method in SPM (Litvak et
al., 2011). Results from the inversion were averaged over a 50 ms sliding time window, with an
18
overlap of 25 ms, between 50-600 ms post-stimulus, leading to the creation of 21 summary time
windows (e.g. 50-100 ms, 75-125 ms, etc.) for each participant and each condition, which were
then exported as 3D NIFTI contrast images in MNI space. These images were spatially smoothed
by a 12 mm FWHM Gaussian kernel before being input into a 2 x 2 x 2 (group x switching x
witnessing) factorial ANOVA to model the effects of group (TD or ASD) and each condition
(switching – Switched or Unswitched – and witnessing – Witnessed or Unwitnessed) on brain
activity. Because two of the factors (switching and witnessing) are repeated across participants,
the statistics model estimation was adjusted for violations of sphericity using the Restricted
Maximum Likelihood (ReML) method (Friston, Stephan, Lund, Morcom, & Kiebel, 2005).
Planned comparison t-tests were performed to evaluate specific within- and between-group
effects of interest, namely (1) brain regions that were more strongly activated in the FB than the
TB condition in TD (TD, FB > TB) and ASD children (ASD, FB > TB); and (2) brain regions
found in (1) that were more active in TD (TD > ASD, FB) and in ASD children (ASD > TD, FB),
which was done by analyzing these latter two contrasts in the context of the interaction between
group (TD or ASD) and condition (FB or TB). Significant peaks of activity are reported at
puncorrected < 0.009 and were labelled according to the CA_ML_18_MNIA atlas (Eickhoff et al.,
2005) available in the Analysis of Function NeuroImages (AFNI) software (Cox, 1996).
Visualization of these areas were created using MRIcron (Rorden, Karnath, & Bonilha, 2007).
19
Chapter 4 Results
4.1 Assessments
For the neurocognitive assessments, t-tests revealed that the TD group had an overall higher IQ
(mean = 119.55 ± 9.49; t(39) = 2.92, p = 0.006; Figure 2A) than the ASD group (mean = 109.68
± 12.10), as measured by the WASI-II, although it is important to note that both groups had
average to above average IQs. The TD group (mean = 25.27 ± 1.80) and the ASD group (mean =
22.82 ± 3.34) also differed on the Theory of Mind subtest of the NEPSY-II (t(37) = 2.94, p =
0.006; Figure 2D), with the TD children scoring higher than the children with ASD on the test,
which is consistent with the classical ToM deficits described the literature on ASD (Baron-
Cohen et al., 1985; Perner et al., 1989). In contrast, there were no significant differences between
the TD group (mean = 216.64 ± 32.71) and the ASD group (mean = 204.00 ± 37.01) on the
WMTB-C (t(39) = 1.16, p = 0.25; Figure 2B), nor on the Inhibition subtest of the NEPSY-II
(t(37) = 1.06, p = 0.30; TD mean = 10.95 ± 3.05, ASD mean = 9.82 ± 3.64; Figure 2C).
On the parent questionnaires, for the BRIEF, the ASD group (mean = 67.41 ± 10.02) scored
considerably higher (t(37) = 7.13, p = 1.92 x 10-8
; Figure 3A) than the TD group (mean = 44.86
± 9.62), indicating that the children with ASD were seen to have more executive functioning
deficits than their TD peers. Likewise, on the SRS and SRS-2, the ASD group (mean = 73.13 ±
10.66) was rated much more severely (t(35) = 7.93, p = 2.49 x 10-9
; Figure 3B) than the TD
group (mean = 44.67 ± 10.92) in terms of their social difficulties. In fact, all of the children with
ASD scored in the mild/moderate to severe clinical range of social impairments, whereas only
two of the twenty-two children in the TD group scored in the mild/moderate range, with the rest
of the TD participants having normal scores.
For ASD symptomology, all but one child with ASD scored above the ADOS comparison score
cutoff for ASD (mean = 6.84 ± 2.12). The one child who did not meet cutoff had his ASD
diagnosis confirmed by his paediatrician using the DSM-IV criteria.
A summary of these results can be found in Table 1.
20
A B
C D
Figure 2 - Boxplots illustrating the scores of the TD and ASD group on the four neurocognitive assessments: (A)
WASI-II, which measured IQ; (B) WMTB-C, which measured working memory capacity; (C) NEPSY-II Inhibition
subtest, which measured inhibitory control; and (D) NEPSY-II ToM subtest, which measured ToM abilities. In (A)
and (D), t-tests showed group differences (p < 0.05), with TD children scoring higher than ASD children in both
cases, whereas in (B) and (C), there were no differences (p > 0.05).
Note: * p < 0.05; ** p < 0.01; *** p <0.001
21
Table 1
Scores on Neurocognitive Assessments and Questionnaires.
4.2 Task Performance
A linear mixed effect model showed main effects of switching and witnessing, as well as an
interaction between the two, for both accuracy (switching: F(1,117) = 100.29, p < 0.0001;
witnessing: F(1,117) = 83.00, p < 0.0001; interaction: F(1,117) = 17.35, p = 0.0001) and reaction
time (switching: F(1,117) = 64.77, p < 0.0001; witnessing: F(1,117) = 113.92, p < 0.0001;
interaction: F(1,117) = 12.26, p = 0.0007). There was no main effect of group (accuracy: F(1,37)
WASI-II WMTB-C NEPSY-II
Inhibition
NEPSY-II Theory of
Mind BRIEF
SRS / SRS-2
ADOS-G / ADOS-2
TD (N)
119.55 ±
9.49
(22)
216.64 ±
32.71
(22)
10.95 ±
3.05
(22)
25.27 ±
1.80
(22)
44.86 ±
9.62
(22)
44.67 ±
10.92
(21)
---
ASD (N)
109.68 ±
12.10
(19)
204.00 ±
37.01
(19)
9.82 ± 3.64
(17)
22.82 ±
3.34
(17)
67.41 ±
10.02
(17)
73.13 ±
10.66
(16)
6.84 ±
2.12
(19)
Note. Mean scores and standard deviations are given here. Below each of the scores is the number of participants
for which data was available.
A B
Figure 3 - The two boxplots above demonstrate how participants were rated on the (A) BRIEF and the (B) SRS and
SRS-2. On both these questionnaires, parents of children with ASD rated their children as having more difficulties
with executive function (p < 0.05; A) and social functioning (p < 0.05; B) than parents of TD children.
Note: * p < 0.05; ** p < 0.01; *** p <0.001
22
= 1.55, p = 0.22; reaction time: F(1,37) = 1.87, p = 0.18), interaction between group and
switching (accuracy: F(1,117) = 0.006, p = 0.94, reaction time: F(1,117) = 0.01, p = 0.90),
interaction between group and witnessing (accuracy: F(1,117) = 1.006, p = 0.32, reaction time:
F(1,117) = 2.92, p = 0.09), or interaction between group, switching, and witnessing (accuracy:
F(1,117) = 0.11, p = 0.74, reaction time: F(1,117) = 0.86, p = 0.36) for either accuracy or
reaction time. Although IQ was significantly higher in the TD group than the ASD group,
including it as a covariate in the model did not account for this difference in accuracy (F(1,37) =
3.114, p = 0.09) or reaction time (F(1,37) = 0.23, p = 0.64), nor did the interaction between
group and IQ (accuracy: F(1,37) = 2.95, p = 0.09; reaction time: F(1,37) = 0.13, p = 0.72).
Post-hoc t-tests revealed highly significant differences between the FB and TB conditions in
terms of accuracy (t(40) = 8.28, p = 1.68 x 10-10
; Figure 4A) and reaction time (t(40) = 6.33, p =
8.21 x 10-8
; Figure 4B). Specifically, participants were less accurate on the FB trials (mean =
79.71 ± 10.93 % correct) than on the TB trials (mean = 92.46 ± 5.85 % correct), and they also
took longer to respond to the FB trials (mean = 1.06 ± 0.22 seconds) compared to the TB trials
(mean = 0.96 ± 0.21 seconds). Taken together, these results suggest that while TD and ASD
children performed similarly on our ToM task, both groups found the FB condition more
challenging than the TB condition, as evident by their poorer accuracy on and longer reaction
time to the FB trials.
A B
Figure 4 – These boxplots contrast the children’s accuracy (A) and reaction time (B) on the FB and TB trials of the
false-belief task. There were no group-level differences in terms of accuracy or RT, i.e. TD children and children
with ASD performed similarly on the task (p > 0.05). However, both groups of children achieved a lower accuracy
(p < 0.05; A) and had a higher reaction time (p < 0.05; B) on the FB trials compared to the TB trials.
Note: * p < 0.05; ** p < 0.01; *** p <0.001
23
4.3 Neuroimaging
A wide variety of brain regions were shown to be active in the within- and between- group
comparisons performed. Table 2 lays out the coordinates, labels, and timing of these areas, along
with their p-values, while Figure 5 gives a visual representation of their activations. Here we
describe areas of activation that are significant at p < 0.009 and that are of particular interest.
4.3.1 Within-group comparisons
4.3.1.1 TD, FB > TB
In the first two time windows of 50-100 ms and 75-125 ms, TD children activated the right
inferior temporal gyrus (rITG) and an area encompassing the left middle temporal gyrus and left
angular gyrus (lMTG/lAG) during the FB condition compared to the TB condition. The latter
region was activated again in the 300-350 ms, 325-375 ms, and 350-400 ms time windows,
spreading to the left middle occipital gyrus (lMOG), and again at 425-475 ms and 450-500 ms.
Between 100-150 ms, the right angular gyrus (rAG) was more active for the FB trials, though its
peak was more superior than its contralateral counterpart in the previous time window ([-50, -70,
22] for lAG vs [34, -70, 50] for rAG).
There were no activations of interest in the 125-175 ms time window, but in the subsequent two
time periods of 150-200 ms and 175-225 ms, the right precuneus (rPreCun) was recruited more
strongly for the FB trials.
Again, nothing of interest appeared between 200-250 ms, although at 225-275 ms, the TD group
showed greater activation for FB in the right middle frontal gyrus (rMFG) and the right middle
orbital gyrus (rMOrbG), which continued until the 275-325 ms time period. The rMFG was also
recruited from the 425-475 ms to 500-550 ms time window. Additionally, the left inferior
temporal gyrus (lITG) was active during the 250-300 ms and 275-325 ms time windows.
From 325-375 ms to 350-400 ms, the rPreCun was active, but this segment of the rPreCun was
more anterior and superior (12, -78, 44) than that previously activated (10, -48, 72).
Subsequently, the left superior parietal lobule (lSPL) was more activated for the FB condition
than the TB condition between 350-400 ms and 375-425 ms. At the same time, the right superior
24
parietal lobule (rSPL), which was adjacent to the rAG mentioned above, was also active, and its
activation extended to the 400-450 ms time window.
In the next few time windows of 400-450 ms to 450-500 ms, the left inferior parietal lobule
(lIPL) and the right inferior temporal gyrus (rITG) were both activated, though the rITG was
much more posterior and superior (52, -46, -18) to the rITG found in the earliest two time
windows (50, -6, -42).
The final region of note, the left inferior temporal gyrus (lITG), was activated starting at the 425-
475 ms time window until 550-600 ms.
4.3.1.2 ASD, FB > TB
In the FB compared to the TB trials, children with ASD began with activating the left middle
temporal gyrus (lMTG) at 50-100ms and 75-125 ms, as well as the left calcarine and left lingual
gyri (lCalG/lLG) from the 75-125 ms to 125-175 ms time window.
At 125-175 ms, the right superior lobule (rSPL) was activated. The site of its peak activity is
very close to that activated in TD children ([36, -62, 58] in the TD group vs [26, -60, 60] in the
ASD group), although it was activated earlier in the children with ASD and for a shorter
duration. The left middle frontal gyrus (lMFG) was also active at the same time, but for a more
sustained period of time, up to the 275-325 ms time window. Interestingly, the location of the
lMFG here almost exactly corresponds to that of the contralateral rMFG seen in the TD children,
and their timing of activation overlapped from the 225-275 ms to the 275-325 ms time window,
with both areas tapering off almost simultaneously. In addition, between 150-200 ms and 200-
250 ms, the left middle occipital gyrus (lMOG) was more active for the FB condition.
The right fusiform gyrus (rFG) was shown to be active beginning at 175-225 ms up to the 225-
275 ms time window. Following this, during the 250-300 ms and 275-325 ms time windows, the
right middle orbital gyrus (rMOrbG) was active. Its region of activity overlapped that of the
rMOrbG in the TD children ([30, 54, -8] in TD children and [40, 52, -10] in children with ASD),
and even their timing almost completely coincided.
In the 275-325 ms time period, the right superior parietal lobule (rSPL) was activated, as was the
left inferior frontal gyrus (lIFG). This rSPL activation abutted a region of simultaneously
25
significant activity in the right angular gyrus (rAG) and right inferior parietal lobule (rIPL),
which lasted until 325-375 ms. This rSPL/rAG/rIPL area was active again from 450-500 ms up
to 550-600 ms and extended to the right supramarginal gyrus (rSMG) at 550-600 ms. The lIFG
remained active up to the 325-375 ms time window. The lIFG appeared again at 450-500 ms, this
time covering a much wider area of the brain and continuing to be active until 550-600 ms.
The most striking activation in this comparison of the FB and TB trials in children with ASD
was the right inferior frontal gyrus (rIFG), which was recruited starting at 300-350 ms and
persisting until 550-600 ms. The timing of the rIFG directly followed the first appearance of an
equivalent rMFG region in the TD group, and it also overlapped both spatially and temporally
during the latter’s second appearance, from the 425-475 ms to the 500-550 ms time window.
Lastly, from 450-500 ms, children with ASD invoked a more anterior portion of the left middle
temporal gyrus (lMTG) than seen at 50-100 ms ([-68, -38, 0] earlier vs [-66, -20, -8] here), until
the 550-600 ms time window.
4.3.2 Between-group comparisons
4.3.2.1 TD > ASD, FB
Only a few areas were significantly more active in the TD than in the ASD group on the FB
compared to the TB trials. The lMTG/lAG was more active at 325-375 ms and, also at 425-475
ms. A contralateral region, the rSPL of the rSPL/rAG/rIPL cluster, was found to be recruited
more strongly from 375-425 ms. Finally, during the next time periods of 425-475 ms and 450-
500 ms, the lITG was more activated in TD children than their ASD counterparts.
4.3.2.2 ASD > TD, FB
In comparison, children with ASD displayed stronger and more persistent activation in several
distinct regions compared to TD children in the FB condition. Firstly, the lMTG was more active
only between 50-100 ms, but the lCalG/lLG showed greater activity for a longer period of time,
from the 75-125 ms to 125-175 ms time window, and from 175-225 ms to 200-250 ms, the rFG
was recruited more by the children with ASD.
During the 275-325 ms time window, the rSPL/rAG/rIPL area was activated significantly more
in the ASD group, and also from 500-550 ms up to 550-600 ms. From the 300-350 ms time
26
window to 325-375 ms, both the lIFG and rIFG were more robustly activated, with the lIFG also
being more active at 475-525 ms up to 550-600 ms, and the rIFG continuing to be more active
until 375-425 ms, and again at 500-550 ms and 525-575 ms.
In the last few time windows from 500-550 ms to 550-600 ms, activation in the lMTG was
shown to be greater in children with ASD relative to TD children.
27
Table 2
Coordinates of Significant Peaks of Brain Activation of Interest in TD Children and Children with ASD in the False-
Belief Task
Region MNI coordinates
Z score p (uncorrected)
x y z
50-100 ms
TD, FB > TB
R Inferior Temporal Gyrus1 50 -6 -42 2.71 1.31 x 10
-5
L Middle Temporal Gyrus2 -46 -64 14 2.57 0.005
ASD, FB > TB
L Middle Temporal Gyrus3 -68 -38 0 2.99 0.001 †
75-125 ms
TD, FB > TB
R Inferior Temporal Gyrus1 50 -4 -34 2.79 0.003
L Middle Temporal Gyrus2 -50 -70 22 2.61 0.005
ASD, FB > TB
L Calcarine Gyrus4 -4 -88 -18 4.54 2.84 x 10
-6 †
L Middle Temporal Gyrus3 -66 -38 -2 2.46 0.007
100-150 ms
TD, FB > TB
R Angular Gyrus5 34 -70 50 3.45 0.0002
ASD, FB > TB
L Lingual Gyrus4 -6 -88 -16 5.47 2.30 x 10
-8 †
125-175 ms
TD, FB > TB
No significant regions of interest
ASD, FB > TB
L Calcarine Gyrus4 -6 -88 -14 4.93 4.02 x 10
-7 †
R Superior Parietal Lobule6 26 -60 60 2.67 0.004
L Middle Frontal Gyrus7 -38 52 10 2.37 0.008
150-200 ms
TD, FB > TB
R Precuneus8 12 -78 44 4.40 5.52 x 10
-6
ASD, FB > TB
L Middle Frontal Gyrus7 -38 52 12 3.14 0.0008
L Middle Occipital Gyrus9 -36 -72 24 2.73 0.003
Note. L = left, R = right. * denotes that the peak was also significant in the TD > ASD, FB contrast. † denotes that
the peak was also significant in the ASD > TD, FB contrast. Numbers in superscript (e.g.1) denote peaks that were
considered to be part of the same region. Bolded peaks are significant at a pFWE < 0.05.
28
Table 2 (Continued)
Coordinates of Significant Peaks of Brain Activation of Interest in TD Children and Children with ASD in the False-
Belief Task
Region MNI coordinates
Z score p (uncorrected) x y z
175-225 ms
TD, FB > TB
R Precuneus8 8 -74 40 2.59 0.005
ASD, FB > TB
L Middle Frontal Gyrus7 -38 52 12 3.29 0.0005
L Middle Occipital Gyrus9 -34 -78 38 2.63 0.004
R Fusiform Gyrus10
38 -62 -20 2.61 0.005 †
200-250 ms
TD, FB > TB
No significant regions of interest
ASD, FB > TB
L Middle Frontal Gyrus7 -38 52 10 3.02 0.001
R Fusiform Gyrus10
36 -62 -22 2.95 0.002 †
L Middle Occipital Gyrus9 -34 -80 38 2.79 0.003
225-275 ms
TD, FB > TB
R Middle Orbital Gyrus11
30 54 -8 2.75 0.003
R Middle Frontal Gyrus12
40 48 16 2.71 0.003
ASD, FB > TB
L Middle Frontal Gyrus7 -36 50 12 3.07 0.001
R Fusiform Gyrus10
38 -62 -22 2.56 0.005
250-300 ms
TD, FB > TB
R Middle Frontal Gyrus12
40 48 10 3.22 0.0006
R Middle Orbital Gyrus11
36 54 -2 3.20 0.0006
L Inferior Temporal Gyrus13
-46 4 -34 2.43 0.008
ASD, FB > TB
R Middle Orbital Gyrus14
40 52 -10 2.92 0.002
L Middle Frontal Gyrus7 -34 54 12 2.73 0.003
Note. L = left, R = right. * denotes that the peak was also significant in the TD > ASD, FB contrast. † denotes that
the peak was also significant in the ASD > TD, FB contrast. Numbers in superscript (e.g.1) denote peaks that were
considered to be part of the same region. Bolded peaks are significant at a pFWE < 0.05.
29
Table 2 (Continued)
Coordinates of Significant Peaks of Brain Activation of Interest in TD Children and Children with ASD in the False-
Belief Task
Region MNI coordinates
Z score p (uncorrected) x y z
275-325 ms
TD, FB > TB
R Middle Frontal Gyrus12
42 46 2 3.11 0.0009
L Inferior Temporal Gyrus13
-48 2 -38 2.58 0.005
ASD, FB > TB
L Inferior Frontal Gyrus15
-48 32 0 3.25 0.0006
R Middle Orbital Gyrus14
42 50 -10 2.74 0.003
L Middle Frontal Gyrus7 -36 54 6 2.63 0.004
R Angular Gyrus6 50 -62 42 2.56 0.005 †
R Superior Parietal Lobule6 38 -52 58 2.53 0.006
300-350 ms
TD, FB > TB
L Angular Gyrus2 -48 -72 24 2.83 0.002
ASD, FB > TB
L Inferior Frontal Gyrus15
-48 32 -6 3.37 0.0003 †
R Inferior Parietal Lobule6 48 -58 44 2.77 0.003
R Inferior Frontal Gyrus16
48 28 24 2.65 0.004 †
R Middle Frontal Gyrus16
42 46 18 2.42 0.008
325-375 ms
TD, FB > TB
R Precuneus17
10 -48 72 3.92 4.46 x 10-5
L Middle Temporal Gyrus2 -52 -70 16 3.25 0.0006 *
ASD, FB > TB
R Inferior Frontal Gyrus16
48 30 24 3.64 0.0001 †
L Inferior Frontal Gyrus15
-48 34 -6 3.42 0.0003 †
R Inferior Parietal Lobule6 48 -52 46 2.41 0.008
Note. L = left, R = right. * denotes that the peak was also significant in the TD > ASD, FB contrast. † denotes that
the peak was also significant in the ASD > TD, FB contrast. Numbers in superscript (e.g.1) denote peaks that were
considered to be part of the same region. Bolded peaks are significant at a pFWE < 0.05.
30
Table 2 (Continued)
Coordinates of Significant Peaks of Brain Activation of Interest in TD Children and Children with ASD in the False-
Belief Task
Region MNI coordinates
Z score p (uncorrected) x y z
350-400 ms
TD, FB > TB
R Precuneus17
10 -48 72 4.06 2.46 x 10-5
L Superior Parietal Lobule18
-14 -78 50 3.61 0.0002
R Superior Parietal Lobule5 36 -62 58 3.40 0.0003
L Middle Occipital Gyrus2 -54 -78 8 3.25 0.0006
ASD, FB > TB
R Inferior Frontal Gyrus16
48 30 18 4.48 3.70 x 10-6
†
375-425 ms
TD, FB > TB
R Superior Parietal Lobule5 38 -58 56 3.80 7.20 x 10
-5 *
L Superior Parietal Lobule18
-20 -76 52 2.61 0.004
ASD, FB > TB
R Inferior Frontal Gyrus16
48 30 18 4.07 2.40 x 10-5
†
400-450 ms
TD, FB > TB
R Inferior Temporal Gyrus19
52 -46 -18 3.76 8.64 x 10-5
R Superior Parietal Lobule5 36 -64 56 2.64 0.004
L Inferior Parietal Lobule20
-42 -52 52 2.47 0.007
ASD, FB > TB
R Inferior Frontal Gyrus16
50 30 14 3.16 0.0008
425-475 ms
TD, FB > TB
R Inferior Temporal Gyrus19
52 -50 -24 3.37 0.0004 *
L Inferior Parietal Lobule20
-38 -62 48 3.14 0.0009
L Middle Occipital Gyrus2 -48 -84 12 3.08 0.001 *
R Middle Frontal Gyrus12
40 48 24 2.76 0.003
ASD, FB > TB
R Inferior Frontal Gyrus16
48 30 16 2.89 0.002
Note. L = left, R = right. * denotes that the peak was also significant in the TD > ASD, FB contrast. † denotes that
the peak was also significant in the ASD > TD, FB contrast. Numbers in superscript (e.g.1) denote peaks that were
considered to be part of the same region. Bolded peaks are significant at a pFWE < 0.05.
31
Table 2 (Continued)
Coordinates of Significant Peaks of Brain Activation of Interest in TD Children and Children with ASD in the False-
Belief Task
Region MNI coordinates
Z score p (uncorrected) x y z
450-500 ms
TD, FB > TB
R Middle Frontal Gyrus12
40 50 22 3.62 0.0001
L Middle Temporal Gyrus2 -52 -72 10 2.93 0.002
L Inferior Parietal Lobule20
-42 -56 54 2.74 0.003
R Inferior Temporal Gyrus19
52 -44 -28 2.53 0.006
ASD, FB > TB
R Inferior Frontal Gyrus16
50 30 18 3.65 0.0001
R Angular Gyrus6 36 -64 42 3.00 0.001
R Inferior Parietal Lobule6 58 -54 38 2.89 0.002
L Inferior Frontal Gyrus15
-46 20 -8 2.69 0.004
L Temporal Pole15
-36 20 -24 2.64 0.004
L Middle Temporal Gyrus21
-66 -20 -8 2.40 0.008
L Inferior Temporal Gyrus15
-56 -4 -30 2.39 0.008
475-525 ms
TD, FB > TB
R Middle Frontal Gyrus12
40 52 18 3.80 7.33 x 10-5
L Inferior Temporal Gyrus22
-52 -60 -20 2.88 0.002
ASD, FB > TB
L Inferior Frontal Gyrus15
-48 22 -10 4.04 2.68 x 10-5
†
R Inferior Frontal Gyrus16
52 30 22 3.60 0.0001
R Inferior Parietal Lobule6 52 -58 44 3.32 0.0004
L Middle Temporal Gyrus21
-66 -24 -2 2.55 0.005
500-550 ms
TD, FB > TB
L Inferior Temporal Gyrus22
-52 -60 -18 2.87 0.002
R Middle Frontal Gyrus12
38 50 20 2.81 0.002
ASD, FB > TB
L Inferior Frontal Gyrus15
-48 22 -14 4.10 2.08 x 10-5
†
R Inferior Frontal Gyrus16
50 32 22 3.50 0.0002 †
R Inferior Parietal Lobule6 54 -56 40 3.20 0.0007 †
L Middle Temporal Gyrus21
-66 -26 0 2.66 0.004 †
Note. L = left, R = right. * denotes that the peak was also significant in the TD > ASD, FB contrast. † denotes that
the peak was also significant in the ASD > TD, FB contrast. Numbers in superscript (e.g.1) denote peaks that were
considered to be part of the same region. Bolded peaks are significant at a pFWE < 0.05.
32
Table 2 (Continued)
Coordinates of Significant Peaks of Brain Activation of Interest in TD Children and Children with ASD in the False-
Belief Task
Region MNI coordinates
Z score p (uncorrected) x y z
525-575 ms
TD, FB > TB
L Inferior Temporal Gyrus22
-54 -62 -16 2.73 0.003
ASD, FB > TB
L Inferior Frontal Gyrus15
-48 24 -14 4.02 2.91 x 10-5
†
R Inferior Frontal Gyrus16
50 32 22 3.48 0.0002 †
R Inferior Parietal Lobule6 48 -58 44 3.11 0.0009 †
L Middle Temporal Gyrus21
-66 -26 0 2.74 0.003 †
550-600 ms
TD, FB > TB
L Inferior Temporal Gyrus22
-54 -62 -16 2.69 0.004
ASD, FB > TB
L Inferior Frontal Gyrus15
-48 26 -16 3.96 3.69 x 10-5
†
R Inferior Frontal Gyrus16
50 32 22 3.48 0.0003
R Inferior Parietal Lobule6 46 -58 46 3.05 0.001 †
R Supramarginal Gyrus6 62 -48 26 2.48 0.006
L Middle Temporal Gyrus21
-66 -26 0 2.74 0.003 †
Note. L = left, R = right. * denotes that the peak was also significant in the TD > ASD, FB contrast. † denotes that
the peak was also significant in the ASD > TD, FB contrast. Numbers in superscript (e.g.1) denote peaks that were
considered to be part of the same region. Bolded peaks are significant at a pFWE < 0.05.
33
TD Group Time (ms)
Region 50-100 75-125 100-150 125-175 150-200 175-225 200-250
rITG1
lMTG/lAG2
rAG/rSPL5
rPreCun8
ASD Group Region 50-100 75-125 100-150 125-175 150-200 175-225 200-250
lMTG3
lCalG/lLG4
rSPL/rAG/rIPL6
lMFG7
lMOG9
rFG10
Figure 5 - Bar graphs and brain images showing the timeline of brain activation for the TD children (top, blue) and the children with ASD (bottom, orange/red). The
numbers in superscript correspond to the ones found in Table 2.
l
M
T
G
rITG lMTG/lAG
lMTG lCalG/lLG
rAG/rSPL
rSPL/rAG/rIPL
lMFG
lMOG
rPreCun
rPreCun
rFG
■ TD, FB > TB
■ ASD, FB > TB
34
TD Group Time (ms)
Region 225-275 250-300 275-325 300-350 325-375 350-400 375-425
lMTG/lAG2
rAG/rSPL5
rMOrbG11
rMFG12
lITG13
rPreCun17
lSPL18
Figure 5 (Continued) - Bar graphs and brain images showing the timeline of brain activation for the TD children (top, blue) and the children with ASD (bottom,
orange/red). The numbers in superscript correspond to the ones found in Table 2.
ASD Group Region 225-275 250-300 275-325 300-350 325-375 350-400 375-425
rSPL/rAG/rIPL6
lMFG7
rFG10
rMOrbG14
lIFG15
rIFG16
rMOrbG
rMFG
lMFG
rFG
lITG
rMOrbG
rSPL/rAG/rIPL
lIFG
lMTG/lAG
rIFG
rIFG
rPreCun rAG/rSPL
lSPL
rAG/rSPL
■ TD, FB > TB
■ ASD, FB > TB
35
TD Group Time (ms)
Region 400-450 425-475 450-500 475-525 500-550 525-575 550-600
lMTG/lAG2
rAG/rSPL5
rMFG12
rITG19
lIPL20
lITG22
ASD Group Region 400-450 425-475 450-500 475-525 500-550 525-575 550-600
rSPL/rAG/rIPL6
lIFG15
rIFG16
lMTG21
Figure 5 (Continued) - Bar graphs and brain images showing the timeline of brain activation for the TD children (top, blue) and the children with ASD (bottom,
orange/red). The numbers in superscript correspond to the ones found in Table 2.
rAG/rSPL
rITG
lIPL
rIFG
lMTG/lAG
rMFG
rSPL/rAG/rIPL
lIFG
lMTG lITG
■ TD, FB > TB
■ ASD, FB > TB
36
Chapter 5 Discussion
ToM is a valuable social skill that is often lacking in children with ASD (Baron-Cohen et al.,
1985; Perner et al., 1989). Aligning with recent literature, this study demonstrated that the brain
regions underlying ToM abilities differed between children with and without ASD, but we
additionally observed that the timing of similarly activated areas also distinguished these two
groups. Based on our results, we propose that whereas TD children utilize commonly identified
ToM brain areas to correctly recognize a false belief, children with ASD draw on supplementary
working memory resources to make up for their inherent deficits in ToM to perform at the same
level as their TD counterparts.
5.1 Performance on Neurocognitive and Behavioural Measures
The neurocognitive assessments used in this study revealed that our two groups of children
differed in IQ and ToM abilities, but not on tests of working memory or inhibition. The
discrepancy in IQ is not surprising, as intellectual problems are common in children with ASD
(Lai, Lombardo, & Baron-Cohen, 2014), and it can be difficult to find IQ-matched children with
ASD (Rao, Raman, & Mysore, 2015). However, all children in our sample fell within two
standard deviations of the median IQ, and the average IQ in our ASD sample was close to, but
above the median. Furthermore, IQ was not a predictor of accuracy or reaction time in our false-
belief task, even when group status was considered, implying that the overall lower IQ in the
children with ASD did not affect their understanding of the task.
The difference in performance on the ToM subtest of the NEPSY-II was also consistent with the
literature on ToM deficits in ASD (Baron-Cohen et al., 1985; Perner et al., 1989), with
participants with ASD performing more poorly on the test than TD participants. Interestingly, the
results from this test and from our false-belief task were incongruent, as the former showed
group differences and the latter did not. This disparity is likely due to two factors. First, the
NEPSY-II ToM subtest and our task measure different aspects of ToM, in that the NEPSY-II
does not gauge solely ToM abilities, but also affective ToM abilities, and the stimuli presented in
this assessment contain richer social contexts compared to the stimuli in the task. Second, these
two measures are administered differently; whereas the NEPSY-II requires interaction with the
37
examiner, the false-belief task only involves responding to a computer screen. A recent study by
Chevallier et al. (2014) found that while children with ASD performed similarly to controls
when given a ToM task on a computer, the control children did comparatively better on the task
when it was administered by a human examiner, as they benefited from the social interaction.
Thus, because these two tests were given in dissimilar social environments, it is likely that it
could have affected participants’ responses.
The significant differences on the parent ratings of executive functioning and social impairment
are consistent with previous work that has found that children with ASD have reduced executive
functioning, as measured by the BRIEF, and that these scores are related to their SRS scores
(Leung, Vogan, Powell, Anagnostou, & Taylor, 2015). Our finding that children with ASD had
higher SRS scores is also in line with the fact that ratings on the SRS have been correlated with
autistic symptomology, as measured by the 3di, ADI-R, and ADOS (Constantino et al., 2003;
Duvekot, van der Ende, Verhulst, & Greaves-Lord, 2015).
In contrast, the two groups of children performed similarly on our false-belief task. We expected
that the children with ASD would be less accurate and take longer to respond to the FB trials, but
instead they did not differ from the TD children. Ceiling effects were not an issue, since no
children were able to achieve 100% accuracy on the trials, and the mean accuracy of both groups
were below 90%. This does not affect the interpretation of our neuroimaging data, as many have
found neural differences despite no behavioural differences (e.g., Colich et al., 2012; Vogan et
al., 2014). However, we found that participants, both TD and ASD, completed fewer correct
trials and responded more slowly to the FB than TB trials, likely indicating the participants found
the FB trials more difficult.
5.2 Timing and Location of Theory of Mind Regions in the Brain
The TD and ASD groups clearly differed in their recruitment of brain regions in response to the
false-belief task, even though they were quite similar behaviourally. While they shared some
areas in common, the onset and latency of these regions were fairly distinct. Below we discuss
the contributions these areas may have to false-belief reasoning and their diverse roles in
children with and without ASD.
38
5.2.1 Timeline of Activation in TD Children
Within the first 125 ms of recognizing a false-belief scenario, TD children activated the right
inferior temporal gyrus (rITG), the left middle temporal gyrus (lMTG; part of the left middle
temporal gyrus/left angular gyrus (lMTG/lAG) cluster), and the right angular gyrus (rAG; part of
the right angular gyrus/right superior parietal lobule (rAG/rSPL) cluster). Given the early
engagement of these areas, they are likely involved in basic visual processing. The rITG is
involved in object recognition in the ventral visual pathway (Mishkin, Ungerleider, & Macko,
1983; Milner & Goodale, 2008), and the lMTG is used for processing the motion of objects
(Beauchamp, Lee, Haxby, & Martin, 2002; Weisberg, van Turennout, & Martin, 2007) and
human bodies, in conjunction with the pSTS (Grosbras, Beaton, & Eickhoff, 2012; Ferri,
Kolster, Jastorff, & Orban, 2013). In addition, the rAG is implicated in visual search (Taylor,
Muggleton, Kalla, Walsh, & Eimer, 2011; Bocca, Töllner, Müller, & Taylor, 2015; Petitet,
Noonan, Bridge, O'Reilly, & O'Shea, 2015). Together, these regions may be detecting the
apparent movement of the ball and Jill in the FB trials by tracking their locations.
Between 150-225 ms, the right precuneus (rPreCun) responded to the FB trials. At this time, its
activation may be reflecting the TD participants realizing that their belief about the ball’s
location is separate from Jill’s, as the rPreCun has been shown to identify disparities between
one’s own perspective and another’s (Vogely et al., 2004; Schurz et al., 2015), and in other false-
belief tasks (Kobayashi, Glover, & Temple, 2006; Sommer et al., 2007; Schneider, Slaughter,
Becker, & Dux, 2014).
The right middle frontal gyrus (rMFG) and right middle orbital gyrus (rMOrbG) were
subsequently activated from 225-325 ms. Their roles may be in re-orienting of attention (Japee,
Holiday, Satyshur, Mukai, & Ungerleider, 2015), which is plausible in this context, since the
regions noted above are activated once again, and in practically the same order, with the
contralateral left inferior temporal gyrus (lITG) being active from 250-325 ms, the lMTG/lAG
from 300-400 ms, the right superior parietal lobule (rSPL; part of the rAG/rSPL cluster) from
350-450 ms, and the rPreCun from 325-400 ms. Whereas their activation before 200 ms was
perhaps automatic in response to the FB situation, the rMFG and rMOrbG may be recruiting
them again to parse the scene more carefully, which may be reflected in the fact that they are
active for longer periods of time. Notably, the peak of the lMTG/lAG area is more superior in
39
this later time window, centred more strongly on the lAG than the lMTG, and then shifts down
toward the lMTG as time passes. As the lAG is part of the lTPJ, and since the lTPJ has shown to
be involved in false belief and perspective taking tasks (Schurz et al., 2013), it may be that
during this period, the lMTG/lAG area is integrating the child’s interpretation of Jill’s thoughts
with the visual scene. Furthermore, the peak of the rAG/rSPL cluster is closer to the rSPL during
this time, and given the rSPL’s involvement in top-down attention and working memory
(Humphreys & Lambon Ralph, 2014), and its connection with the rMFG (Ma et al., 2012;
Schmidt et al., 2014), the rAG/rSPL cluster is perhaps drawing on working memory resources to
remember what happened before Jill went away to understand the FB scenario. Also, the region
of the rPreCun activated is more superior than at 150-225 ms. As the dorsal parietal cortex may
be responsible for top-down attention to memory, while the ventral parietal cortex may be
concerned instead with bottom-up attention to memory (Burianová, Ciaramelli, Grady, &
Moscovitch, 2012), perhaps the rPreCun at this time is actively, rather than automatically,
recognizing that Jill’s perspective is different.
The left superior parietal lobule (lSPL) is subsequently activated between 350-425 ms. Previous
work has implicated it in the mirror neuron system (Molenberghs, Brander, Mattingley, &
Cunnington, 2010), a network of brain regions that has been often linked to ToM processing
(Gallese & Goldman, 1998; Iacoboni et al., 2006; Uddin, Iacobini, Lange, & Keenan, 2007;
Libero et al., 2014). It has also been associated with increasing working memory load, along
with the rITG (Mazoyer, Wicker, & Fonlupt, 2002), which is also active at around the same time,
between 400-500 ms. In addition, the concurrent recruitment of the left inferior parietal lobule
(lIPL) between 400-500 ms may reflect an understanding that Jill likely has a false belief, since
the lIPL has been shown to be selectively active for the resolution of incongruities (Chan et al.,
2013), deception (Lisofsky, Kazzer, Heekeren, & Prehn, 2014), and counterfactual reasoning
(Van Hoeck et al., 2014). The reactivation of the rMFG between 425-550 ms, may suggest that it
is interacting with the above three regions. Considering the latency of this activation, and that the
rMFG is involved in logical reasoning (Porcaro et al., 2014), it is possible that it is working with
the lSPL, rITG, and lIPL to help resolve the disparity between Jill’s belief of where the ball is
and its actual location using the working memory and mirror neuron systems.
Since the lITG has been implicated in visual memory (Hamamé et al., 2012; Vilberg & Rugg,
2012), then perhaps from 475-600 ms, TD children are using their lITG to ensure that their
40
assumption that Jill has a false belief is correct by trying to remember where Jill saw the ball last.
The lITG also may play a role in response inhibition and selection (Chiang et al., 2013), so it
might additionally be involved in choosing the correct answer to the FB trials, which is the
opposite of their own knowledge of the situation.
5.2.2 Timeline of Activation in Children with ASD
Children with ASD, similar to TD children, activated the lMTG from 50-125 ms, perhaps also to
observe the movement of the objects and characters in the trial, but they relied on the left
calcarine gyrus/left lingual gyrus (lCalG/lLG) between 75-175 ms instead of the rITG to process
the basic features of the visual stimulus, as they are both classical visual processing and encoding
regions (Arroyo, Lesser, Poon, Webber, & Gordon, 1997; Klein, Paradis, Poline, Kosslyn, & Le
Bihan, 2000; Machielsen, Rombouts, Barkhof, Scheltens, & Witter, 2000; Hayakawa, Miyauchi,
Fujimaki, Kato, & Yagi, 2003; Moradi et al., 2003). The children with ASD also activated the
rSPL (part of the right superior parietal lobule/right angular gyrus/right inferior parietal lobule
(rSPL/rAG/rIPL) cluster) from 125-175 ms possibly to encode the visual scene and keep it in
working memory, as suggested above. Also, the location of the rSPL overlapped with the
contralateral lMTG/lAG region activated early on in TD children, and so it may be triggering
visual search to look for relevant cues.
At around 125-325 ms, the left middle frontal gyrus (lMFG) was active. Previous work has
shown its involvement with ToM (Péron et al., 2010), and in particular, Zhang, Sha, Zheng,
Ouyang, and Li (2009) demonstrated its role in inhibiting one’s personal knowledge during a
false-belief task. Thus, the lMFG may be involved in monitoring responses, as children with
ASD are known to have difficulty with response inhibition (Chmielewski & Beste, 2015).
During the same time as the lMFG, the left middle occipital gyrus (lMOG), right fusiform gyrus
(rFG), and rMOrbG were also active, with the lMOG being recruited from 150-250 ms, the rFG
from 175-275 ms, and the rMOrbG from 250-325 ms. The lMOG has been shown to be active
during false-belief and visual perspective-taking tasks, and it has been suggested that it plays a
part in transforming a scene to understand a different perspective (Schurz et al., 2013). In
contrast, the rFG is responsible for processing objects and faces (Vandenbulcke, Peeters, Fannes,
& Vandenberghe, 2006; Morris, Pelphrey, & McCarthy, 2007; Bruffaerts et al., 2013) and
biological motion in children (Lichtensteiger, Loenneker, Bucher, Martin, & Klaver, 2008). In
41
addition, the rMOrbG was likely performing a similar task as in the TD children, where it was
responsible for re-orienting attention. Therefore, during this time period, these three regions were
likely working together to comprehend Jill’s view of the scene, with the lMOG taking Jill’s
perspective, the rFG processing the complex visual scene, and the rMOrbG utilizing working
memory resources, as the lMFG tried to suppress the children’s own viewpoint.
The activation of the rAG of the rSPL/rAG/rIPL cluster between 275-375 ms may have served
the same function as in the TD group, where the rAG was promoting a visual search. However,
unlike the TD children, the children with ASD activated the contralateral IPL, the right inferior
parietal lobule (rIPL), during this time. The rIPL is proposed to be involved in understanding
actions (Gobbini et al., 2007; Marsh, Mullett, Ropar, & Hamilton, 2014), which has been
replicated in MEG (Vistoli, Brunet-Gouet, Lemoalle, Hardy-Baylé, & Passerieux, 2011), and
generally in both verbal and non-verbal ToM tasks (Kobayashi, Glover, & Temple, 2007). The
left inferior frontal gyrus (lIFG) was simultaneously active from 275-375 ms, and it also has
been shown to be active in individuals with ASD while processing the intentions of actions
(Libero et al., 2014). Furthermore, this region has traditionally been defined as Broca’s area,
which deals with language production (Broca, 1861), and so several studies have linked its
activation with working memory and active maintenance of information (Braver et al., 1997;
Cohen et al., 1997), specifically with verbal rehearsal of this information (Zarahn, Rakitin,
Abela, Flynn, & Stern, 2005; Powell, Kemp, & Garcia-Finaña, 2012). The rIPL may also play a
role in keeping information in memory through verbal repetition (Zarahn et al., 2005; Urbain et
al., 2013); thus, these three regions may have been working in concert to understand the
consequences of Jack’s movement of the ball on Jill’s beliefs by resorting to verbal strategies.
Beginning at 300 ms, children with ASD employed the right inferior frontal gyrus (rIFG), up
until 600 ms. The rIFG has been shown consistently to be involved in inhibition and executive
control (Aron, Fletcher, Bullmore, Sahakian, & Robbins, 2003; Kenner et al., 2010; Zhang,
Hughes, & Rowe, 2012; Hughes, Johnston, Fulham, Budd, & Michie, 2013). In the context of
this task, and bearing in mind the duration of this activation, children with ASD were likely
relying strongly on the rIFG to inhibit their own beliefs about where the ball is located.
The rSPL/rAG/rIPL and the lIFG were reactivated between 450-600 ms, and the lMTG was
additionally recruited for the same time period. The former two areas likely served the same
42
purposes as before, namely attempting to integrate the true location of the ball with what Jill
previously thought (before leaving the scene) through verbal rehearsal. It is important to note,
though, that the rSPL/rAG/rIPL at this time point extended to the right supramarginal gyrus/right
superior temporal sulcus (rSMG/rSTS) area, which is part of the rTPJ. While some studies have
shown that the rTPJ is central to ToM processing (Saxe & Wexler, 2005; Rabin et al., 2010),
there is converging evidence that the dorsal rTPJ is concerned with working memory and re-
orienting of attention, while the ventral TPJ is exclusive for ToM (Decety & Lamm, 2007;
Scholz et al., 2009). Based on the location of this rSPL/rAG/rIPL region, it appeared to be
situated in the more dorsal portion of the TPJ, and so it may instead reflect attentional processes.
The lMTG here is much more anterior than the portion of the lMTG that analyzes object motion,
so instead of being involved in relatively basic visual processing, it probably is participating in
resolving the difference between the children’s own thoughts and those of Jill, as the lMTG has
been implicated in detecting incongruities (Chan et al., 2013) and counterfactual thinking (Van
Hoeck et al., 2013). Hence, these three regions may be coordinating the union of reality and Jill’s
perspective to form her false belief.
5.2.3 Typically-Developing Children Rely Mainly on ToM Regions for False-Belief Processing, Whereas Children with ASD Additionally Use Working Memory and Inhibition
Based on the interpretations given above, TD children and children with ASD appear to recruit
fairly distinct networks of brain areas for false-belief processing, with the TD children utilizing
classical ToM regions, such as the precuneus and the lTPJ, and the children with ASD drawing
on a number of areas responsible for working memory and inhibition, such as the rIPL, the lIFG,
and the rIFG. A direct comparison of the two groups reveals a similar conclusion.
The lAG/lMTG, rSPL, and lITG all had significantly greater activity in TD children than in
children with ASD. The lAG/lMTG was more active at 325-375 ms and 425-475 ms, the rSPL at
375-425 ms, and the lITG at 425-500 ms. What is immediately striking is that all these
differences occur relatively late, past 300 ms, suggesting that while automatic processes may be
similar between the two groups, TD children are applying a different top-down cognitive
approach than children with ASD. As proposed above, TD children are perhaps appropriately
making use of ToM regions, such as the lAG/lMTG, and selectively using working memory and
inhibition regions, such as the rSPL and lITG, though not reliant on the latter two.
43
On the other hand, a variety of regions were more active in children with ASD compared to TD
children, such as the lMTG, lCalG/lLG, rFG, rSPL/rAG/rIPL, lIFG, rIFG, and a more anterior
lMTG region. The significant activation in the posterior lMTG, lCalG/lLG, and rFG from 50-100
ms, 75-200 ms, and 175-250 ms, respectively, likely reflect atypical visual processing that has
been established in ASD (Behrmann, Thomas, & Humphreys, 2006; Simmons et al., 2009).
Between 275-325 ms, and again between 475-600 ms, the recruitment of the rSPL/rAG/rIPL,
lIFG, rIFG, and anterior lMTG shows the greater dependence that the children with ASD have
on working memory and inhibitory processes to interact with ToM-related regions. These results
demonstrate how children with ASD may use alternative neural strategies to perform a ToM task
similarly to TD children.
5.2.4 The Intersection between Theory of Mind and Working Memory
Given that the children with ASD appeared to rely on working memory during our false-belief
ToM task, it is important to briefly discuss the apparent overlap that the ToM and working
memory networks have in the literature. As mentioned above, different sections of one of the key
ToM network hubs, the TPJ, have been shown to serve distinct functions, with the dorsal region
being responsible for attention, and the ventral region for ToM (Decety & Lamm, 2007; Scholz
et al., 2009), and it may also underlie several other functions (Igelström, Webb, & Graziano,
2015). In addition, other crucial ToM network regions, such as the IPL, AG, and precuneus, have
been implicated in attention and working memory studies, as well (Kizilirmak, Rösler, Bien, &
Khader, 2015; Urbain, Pang, & Taylor, 2015). Taking into consideration this overlap between
ToM and working memory, it raises the question of how specific these proposed ToM regions
are to ToM itself, and it highlights the need for adequate working memory controls in ToM tasks,
an issue which has also been brought up by Spreng and Mar (2012).
Clearly, the false-belief task used in this present study was not without working memory
confounds, as the TD group activated working memory regions as well. However, we performed
exploratory analyses of our data to examine the extent to which certain regions were recruited for
working memory, by comparing the FB trials to another set of TB trials, the Unwitnessed-
Unswitched condition, which requires a similar cognitive load (as Jill also disappears in these
trials), but which is also an appropriate ToM contrast. This analysis showed that, for example, in
the 375-425 ms time window, even when working memory was accounted for, TD children still
44
showed higher activation in the rSPL compared to children with ASD, but on the other hand,
children with ASD no longer showed greater activation in the lIFG or the rIFG, emphasizing
their roles as working memory regions (Supplementary Figure 2). In other words, when the
children with ASD were presented with an equally memory-intensive TB scenario, they recruited
similar areas for the TB and FB trials, so it can be concluded that these regions are related to
working memory processes. The rationale for not using this condition to represent true belief,
though, was due to the fact that the study’s design included fewer trials in this condition, namely
50 trials, and so it cannot be compared as robustly to the FB condition, which had 100 trials.
Regardless, this comparison compellingly suggests that children with ASD have a strong
working memory component when engaging in ToM.
5.3 Summary
Our neuroimaging results suggest that unlike TD children, who primarily use ToM regions
during false-belief reasoning, children with ASD, while capable of correctly inferring others’
thoughts, are utilizing additional brain areas that are responsible for working memory and
inhibition, perhaps because their ToM regions are not functioning efficiently. Their reliance on
these two domains makes sense in the context of their neurocognitive results, which showed no
difference in working memory or inhibition measures compared to controls.
5.4 Limitations and Future Directions
While this study demonstrated distinct differences between the TD and ASD groups, it is not
without its caveats. Although we found IQ to be different between the two groups of children, it
was not controlled for in our neuroimaging analyses. This decision was due to the fact that IQ
did not adequately predict accuracy or reaction time on the false-belief task, and it has been
suggested that controlling for IQ may lead to misinterpretation of results, as IQ differences are a
central and defining symptom of certain disorders (Dennis et al., 2013).
It was surprising that neither the rTPJ nor the mPFC appeared prominently in our results,
considering their ubiquitous presence in the ToM literature. However, it is possible that these
areas did not play a role in our study as their functions were either present in all trials or were not
necessary for this task. The rTPJ has been shown to be activated for both TB and FB scenarios
(Aichhorn et al., 2009), and as we compared these two trials in our analyses, the rTPJ’s activity
45
was likely cancelled out. Thus, it may be interesting to compare the FB trials instead to a
different control condition, such as physical causality, to observe the rTPJ’s role. Also, the
mPFC appears to be more involved in attribution of intentions and specifically processing social
intentions (Brunet, Sarfati, Hardy-Baylé, & Decety, 2000; Ciaramidaro et al., 2007), but since
our false-belief task requires neither of these processes, it is logical, in that case, that the mPFC
need not be recruited. Alternatively, since activation of the rTPJ and mPFC has been largely
reported in adult studies, it may be that these areas are still developing in children, and so their
roles and activation are not as apparent in our study.
As our study involved the use of working memory, future work should have an appropriate
working memory comparison task or condition. In addition, neuroimaging results could be
improved by including time-course information for regions of interest to better delineate these
regions’ exact timing, since the time windows used above averaged activity over the 50-ms time
period. Finally, it would be interesting to investigate the connections between frontal and parietal
regions in the ToM network during this task using connectivity and diffusion tensor imaging
measures, as our results showed many simultaneous frontal and parietal activations, suggesting
some coherence between them.
5.5 Conclusions
This study investigated differences in the timing and location of the neural correlates of ToM
processing between TD children and children with ASD. Using MEG, not only were we able to
detect the distinct areas that were activated, but we were also able to observe differences in
timing of similarly recruited regions between the two groups due to MEG’s ability to tease apart
temporal differences, which no other neuroimaging technique can tell us with comparable
resolution. In addition, measuring this temporal domain allowed us to establish the sequence of
activation and thus the roles each area might play in ToM processing. We propose that while TD
children activate appropriate ToM regions during false-belief reasoning, children with ASD
instead activate additional working memory and inhibition-related areas to perform similarly to
the TD children. These results are significant to the literature on ASD as they not only inform us
on how ToM processes can be preserved in some children with high-functioning ASD, but they
also demonstrate strategies that could be used in interventions to improve ToM in ASD, and thus
lead to better social outcomes for children with ASD.
46
References
Aichhorn, M., Perner, J., Weiss, B., Kronbichler, M., Staffen, W., & Ladurner, G. (2009).
Temporo-parietal junction activity in theory-of-mind tasks: falseness, beliefs, or attention.
Journal of Cognitive Neuroscience. 21(6), 1179-1192.
Allison, T., Puce, A., & McCarthy, G. (2000). Social perception from visual cues: role of the
STS region. Trends in Cognitive Sciences. 4(7), 267-278.
Anninos, P.A., Anogianakis, G., Lehnertz, K., Pantev, C., & Hoke, M. (1987). Biomagnetic
measurements using squids. The International Journal of Neuroscience. 37(3-4), 149-
168.
Aron, A.R., Fletcher, P.C., Bullmore, E.T., Sahakian, B.J., & Robbins, T.W. (2003). Stop-signal
inhibition disrupted by damage to right inferior frontal gyrus in humans. Nature
Neuroscience. 6(2), 115-116.
Arroyo, S., Lesser, R.P., Poon, W.T., Webber, W.R., & Gordon, B. (1997). Neuronal generators
of visual evoked potentials in humans: visual processing in the human cortex. Epilepsia.
38(5), 600-610.
Assaf, M., Hyatt, C.J., Wong, C.G., Johnson, M.R., Schultz, R.T., Hendler, T., & Pearlson, G.D.
(2013). Mentalizing and motivation neural function during social interactions in autism
spectrum disorders. Neuroimage: Clinical. 3, 321-331.
Bahnemann, M., Dziobek, I., Prehn, K., Wolf, I., & Heekeren, H.R. (2010). Sociotopy in the
temporoparietal cortex: common versus distinct processes. Social Cognitive and Affective
Neuroscience. 5(1), 48-58.
Baron-Cohen, S. (1988). Social and pragmatic deficits in autism: cognitive or affective? Journal
of Autism and Developmental Disorders. 18(3), 379-402.
Baron-Cohen, S., Baldwin, D.A., & Crowson, M. (1997). Do children with autism use the
speaker's direction of gaze strategy to crack the code of language? Child Development.
68(1), 48-57.
47
Beauchamp, M.S., Lee, K.E., Haxby, J.V., & Martin, A. (2002). Parallel visual motion
processing streams for manipulable objects and human movements. Neuron. 34(1), 149-
159.
Beaumont, R., & Newcombe, P. (2006). Theory of mind and central coherence in adults with
high-functioning autism or Asperger syndrome. Autism. 10(4), 365-382.
Behrmann, M., Thomas, C., & Humphreys, K. (2006). Seeing it differently: visual processing in
autism. Trends in Cognitive Science. 10(6), 258-264.
Bird, C.M., Castelli, F., Malik, O., Frith, U., & Husain, M. (2004). The impact of extensive
medial frontal lobe damage on `Theory of Mind' and cognition. Brain. 127, 914-928.
Bocca, F., Töllner, T., Müller, H.J., & Taylor, P.C. (2015) The Right Angular Gyrus Combines
Perceptual and Response-related Expectancies in Visual Search: TMS-EEG Evidence.
Brain Stimulation. 8(4): 816-822.
Braver, T.S., Cohen, J.D., Nystrom, L.E., Jonides, J., Smith, E.E., & Noll, D.C. (1997). A
parametric study of prefrontal cortex involvement in human working memory.
Neuroimage. 5(1), 49-62.
Brieber, S., Neufang, S., Bruning, N., Kamp-Becker, I., Remschmidt, H., Herpertz-Dahlmann,
B., Fink, G.R., & Konrad, K. (2007). Structural brain abnormalities in adolescents with
autism spectrum disorder and patients with attention deficit/hyperactivity disorder.
Journal of Child Psychology and Psychiatry. 48(12), 1251-1258.
Broca, P. (1861). Remarques sur le siege de la faculté du langage articulé, suivies d’une
observation d’aphémie (perte de la parole) [Remarks on the seat of the faculty of
articulated language, following an observation of aphemia (loss of speech)]. Bulletin de la
Société Anatomique Paris. 6, 330-357.
Bruffaerts, R., Dupont, P., De Grauwe, S., Peeters, R., De Deyne, S., Storms, G., &
Vandenberghe, R. (2013). Right fusiform response patterns reflect visual object identity
rather than semantic similarity. Neuroimage. 83, 87-97.
48
Brunet, E., Sarfati, Y., Hardy-Baylé, M.C., & Decety, J. (2000). A PET investigation of the
attribution of intentions with a nonverbal task. Neuroimage. 11(2), 157-166.
Buitelaar, J.K., van der Wees, M., Swaab-Barneveld, H., & van der Gaag, R.J. (1999). Theory of
mind and emotion-recognition functioning in autistic spectrum disorders and in
psychiatric control and normal children. Developmental Psychopathology. 11(1), 39-58.
Burianová, H., Ciaramelli, E., Grady, C.L., & Moscovitch, M. (2012). Top-down and bottom-up
attention-to-memory: mapping functional connectivity in two distinct networks that
underlie cued and uncued recognition memory. Neuroimage. 63(3), 1343-1352.
Caillies, S., Bertot, V., Motte, J., Raynaud, C., & Abely, M. (2014). Social cognition in ADHD:
irony understanding and recursive theory of mind. Research in Developmental
Disabilities. 35(11), 3191-3198.
Calarge, C., Andreasen, N.C., & O’Leary, D.S. (2003). Visualizing how one brain understands
another: a PET study of theory of mind. American Journal of Psychiatry. 160(11), 1954-
1964.
Camaioni, L., Perucchini, P., Muratori, F., Parrini, B., & Cesari, A. (2003). The communicative
use of pointing in autism: developmental profile and factors related to change. European
Psychiatry. 18(1), 6-12.
Cao, B., Li, Y., Li, F., & Li, H. (2012). Electrophysiological difference between mental state
decoding and mental state reasoning. Brain Research. 1464, 53-60.
Capps, L., Losh, M., & Thurber, C. (2000). "The frog ate the bug and made his mouth sad":
narrative competence in children with autism. Journal of Abnormal Child Psychology.
28(2), 193-204.
Carrington, S.J., & Bailey, A.J. (2009). Are there theory of mind regions in the brain? A review
of the neuroimaging literature. Human Brain Mapping. 30(8), 2313-2335.
Chan, Y.C., Chou, T.L., Chen, H.C., Yeh, Y.C., Lavallee, J.P., Liang, K.C., & Chang, K.E.
(2013). Towards a neural circuit model of verbal humor processing: an fMRI study of the
neural substrates of incongruity detection and resolution. Neuroimage. 66, 169-176.
49
Chevallier, C., Grees, J., Molesworth, C., Berthoz, S., & Happé, F. (2012). Brief report:
Selective social anhedonia in high functioning autism. Journal of Autism and
Developmental Disorders. 42(7), 1504-1509.
Chevallier, C., Kohls, G., Troiani, V., Brodkin, E.S., & Schultz, R.T. (2012). The social
motivation theory of autism. Trends in Cognitive Sciences. 16(4), 231-239.
Chevallier, C., Parish-Morris, J., Tonge, N., Le, L., Miller, J., & Schultz, R.T. (2014).
Susceptibility to the audience effect explains performance gap between children with and
without autism in a theory of mind task. Journal of Experimental Psychology: General.
143(3), 972-979.
Chiang, H.S., Motes, M.A., Mudar, R.A., Rao, N.K., Mansinghani, S., Brier, M.R., Maguire,
M.J., Kraut, M.A., & Hart, J. Jr. Semantic processing and response inhibition.
Neuroreport. 24(16), 889-893.
Chmielewski, W.X., & Beste, C. (2015). Action control processes in autism spectrum disorder--
insights from a neurobiological and neuroanatomical perspective. Progress in
Neurobiology. 124, 49-83.
Ciaramidaro, A., Adenzato, M., Enrici, I., Erk, S., Pia, L., Bara, B.G., & Walter, H. (2007). The
intentional network: how the brain reads varieties of intentions. Neuropsychologia.
45(13), 3105-3113.
Cohen, J.D., Perlstein, W.M., Braver, T.S., Nystrom, L.E., Noll, D.C., Jonides, J., & Smith, E.E.
(1997). Temporal dynamics of brain activation during a working memory task. Nature.
386(6625), 604-608.
Colich, N.L., Wang, A.T., Rudie, J.D., Hernandez, L.M., Bookheimer, S.Y., & Dapretto, M.
(2012). Atypical Neural Processing of Ironic and Sincere Remarks in Children and
Adolescents with Autism Spectrum Disorders. Metaphor and Symbol. 27(1), 70-92.
Colle, L., Baron-Cohen, S., Wheelwright, S., & van der Lely, H.K. (2008). Narrative discourse
in adults with high-functioning autism or Asperger syndrome. Journal of Autism and
Developmental Disorders. 38(1), 28-40.
50
Constantino, J.N., Davis, S.A., Todd, R.D., Schindler, M.K., Gross, M.M., Brophy, S.L.,
Metzger, L.M., Shoushtari, C.S., Splinter, R., & Reich, W. (2003). Validation of a brief
quantitative measure of autistic traits: comparison of the social responsiveness scale with
the autism diagnostic interview-revised. Journal of Autism and Developmental Disorders.
33(4), 427-433.
Constantino, J.N., & Gruber, C.P. (2005). Social Responsiveness Scale. Los Angeles, CA:
Western Psychological Services.
Constantino, J.N., & Gruber, C.P. (2012). Social Responsiveness Scale, Second Edition. Los
Angeles, CA: Western Psychological Services.
Cox, R.W. (1996). AFNI: software for analysis and visualization of functional magnetic
resonance neuroimages. Computers and Biomedical Research, an International Journal.
29(3), 162-173.
Dayan, E., Sella, I., Mukovskiy, A., Douek, Y., Giese, M.A., Malach, R., & Flash, T. (2014).
The Default Mode Network Differentiates Biological From Non-Biological Motion.
Cerebral Cortex. Advance online publication. doi: 10.1093/cercor/bhu199.
De Villiers, J. (2007). The Interface of Language and Theory of Mind. Lingua. International
Review of General Linguistics. Revue Internationale de Linguistique Generale. 117(11),
1858–1878.
Decety, J., & Lamm, C. (2007). The role of the right temporoparietal junction in social
interaction: how low-level computational processes contribute to meta-cognition.
Neuroscientist. 13(6), 580-593.
Demurie, E., Roeyers, H., Baeyens, D., & Sonuga-Barke, E. (2011). Common alterations in
sensitivity to type but not amount of reward in ADHD and autism spectrum disorders.
Journal of Child Psychology and Psychiatry. 52(11), 1164-1173.
Dennis, M., Francis, D.J., Cirino, P.T., Schachar, R., Barnes, M.A., & Fletcher, J.M. (2009).
Why IQ is not a covariate in cognitive studies of neurodevelopmental disorders. Journal
of the International Neuropsychological Society: JINS. 15(3), 331–343.
51
Dennis, M., Simic, N., Gerry Taylor, H., Bigler, E.D., Rubin, K., Vannatta, K., Gerhardt, C.A.,
Stancin, T., Roncadin, C., & Yeates, K.O. (2012). Theory of mind in children with
traumatic brain injury. Journal of the International Neuropsychological Society. 18(5),
908-916.
Dodell-Feder, D., Koster-Hale, J., Badny, M., & Saxe, R. (2011). fMRI item analysis in a theory
of mind task. Neuroimage. 55(2), 705-712.
Doyle-Thomas, K.A., Lee, W., Foster, N.E., Tryfon, A., Ouimet, T., Hyde, K.L., Evans, A.C.,
Lewis, J., Zwaigenbaum, L., Anagnostou, E., & NeuroDevNet ASD Imaging Group.
(2015). Atypical functional brain connectivity during rest in autism spectrum disorders.
Annals of Neurology. 77(5), 866-876.
Dufour, N., Redcay, E., Young, L., Mavros, P.L., Moran, J.M., Triantafyllou, C., Gabrieli, J.D.,
& Saxe, R. (2013). Similar brain activation during false belief tasks in a large sample of
adults with and without autism. PLoS One. 8(9), 1-13.
Duvekot, J., van der Ende, J., Verhulst, F.C., & Greaves-Lord, K. (2015). The Screening
Accuracy of the Parent and Teacher-Reported Social Responsiveness Scale (SRS):
Comparison with the 3Di and ADOS. Journal of Autism and Developmental Disorders.
45(6), 1658-1672.
Eickhoff, S.B., Stephan, K.E., Mohlberg, H., Grefkes, C., Fink, G.R., Amunts, K., & Zilles, K.
(2005). A new SPM toolbox for combining probabilistic cytoarchitectonic maps and
functional imaging data. Neuroimage. 25(4), 1325-1335.
Ferri, S., Kolster, H., Jastorff, J., & Orban, G.A. (2013). The overlap of the EBA and the MT/V5
cluster. Neuroimage, 66, 412-425.
FIL Methods Group. (2014). Statistical Parametric Mapping 12. Leopold Muller Functional
Imaging Laboratory in the Wellcome Trust Centre for Neuroimaging at University
College London. London, United Kingdom. http://www.fil.ion.ucl.ac.uk/spm/.
52
Fishman, I., Keown, C.L., Lincoln, A.J., Pineda, J.A., & Müller, R.A. (2014). Atypical cross talk
between mentalizing and mirror neuron networks in autism spectrum disorder. JAMA
Psychiatry. 71(7), 751-760.
Friston, K.J., Stephan, K.E., Lund, T.E., Morcom, A., & Kiebel, S. (2005). Mixed-effects and
fMRI studies. Neuroimage. 24(1), 244-252.
Fukui, H., Murai, T., Shinozaki, J., Aso, T., Fukuyama, H., Hayashi, T., & Hanakawa, T. (2006).
The neural basis of social tactics: An fMRI study. Neuroimage. 32(2), 913-920.
Gallagher, H.L., & Frith, C.D. (2003). Functional imaging of 'theory of mind'. Trends in
Cognitive Sciences. 7(2), 77-83.
Gallagher, H.L., Happe, F., Brunswick, N., Fletcher, P.C., Frith, U., & Frith, C.D. (2000).
Reading the mind in cartoons and stories: an fMRI study of ‘theory of mind’ in verbal
and nonverbal tasks. Neuropsychologia. 38(1), 11-21.
Gallese, V., & Goldman, A. (1998). Mirror neurons and the simulation theory of mind-reading.
Trends in Cognitive Science. 2(12), 493-501.
Gioia, G.A., Isquith, P.K., Guy, S.C., & Kenworthy, L. (2000). Behavior rating inventory of
executive function. Odessa, FL: Psychological Assessment Resources.
Gobbini, M.I., Koralek, A.C., Bryan, R.E., Montgomery, K.J., & Haxby, J.V. (2007). Two takes
on the social brain: a comparison of theory of mind tasks. Journal of Cognitive
Neuroscience. 19(11), 1803-1814.
Grezes, J., Frith, C.D., & Passingham, R.E. (2004). Inferring false beliefs from the actions of
oneself and others: an fMRI study. Neuroimage. 21(2), 744-750.
Grosbras, M.-H., Beaton, S., & Eickhoff, S.B. (2012). Brain regions involved in human
movement perception: a quantitative voxel-based meta-analysis. Human Brain Mapping,
33, 431-454.
53
Gweon, H., & Saxe, R. (2013). Developmental Cognitive Neuroscience of Theory of Mind. In
J.L.R. Rubenstein, P. Rakic (Eds.), Neural Circuit Development and Function in the
Brain. (367-377). Oxford: Academic Press.
Hale, C.M., & Tager-Flusberg, H. (2005). Social communication in children with autism: the
relationship between theory of mind and discourse development. Autism. 9(2), 157-178.
Hamamé, C.M., Vidal, J.R., Ossandón, T., Jerbi, K., Dalal, S.S., Minotti, L., Bertrand, O.,
Kahane, P., & Lachaux, J.P. (2012). Reading the mind's eye: online detection of visuo-
spatial working memory and visual imagery in the inferior temporal lobe. Neuroimage.
59(1), 872-879.
Happé, F.G.E. (1995). The role of age and verbal ability in the theory of mind task performance
of subjects with autism. Child Development. 66(3), 843-855.
Happé, F., Ehlers, S., Fletcher, P., Frith, U., Johansson, M., Gillberg, C., Dolan, R., Frackowiak,
R., & Frith, C. (1996). 'Theory of mind' in the brain. Evidence from a PET scan study of
Asperger syndrome. Neuroreport. 8(1), 197-201.
Hari, R., & Salmelin, R. (2012). Magnetoencephalography: From SQUIDs to neuroscience.
Neuroimage 20th anniversary special edition. Neuroimage. 61(2), 386-396.
Hartwright, C.E., Apperly, I.A., & Hansen, P.C. (2014). Representation, control, or reasoning?
Distinct functions for theory of mind within the medial prefrontal cortex. Journal of
Cognitive Neuroscience. 26(4), 683-698.
Hasegawa, N., Kitamura, H., Murakami, H., Kameyama, S., Sasagawa, M., Egawa, J., Endo, T.,
& Someya, T. (2013). Neural activity in the posterior superior temporal region during eye
contact perception correlates with autistic traits. Neuroscience Letters. 549, 45-50.
Hayakawa, T., Miyauchi, S., Fujimaki, N., Kato, M., & Yagi, A. (2003). Information flow
related to visual search assessed using magnetoencephalography. Brain Research:
Cognitive Brain Research. 15(3), 285-295.
Herrington, J.D., Nymberg, C., & Schultz, R.T. (2011). Biological motion task performance
predicts superior temporal sulcus activity. Brain and Cognition. 77(3), 372-381.
54
Hervé, P.Y., Razafimandimby, A., Jobard, G., & Tzourio-Mazoyer, N. (2013). A shared neural
substrate for mentalizing and the affective component of sentence comprehension. PLoS
One. 8(1), 1-12.
Hughes, M.E., Johnston, P.J., Fulham, W.R., Budd, T.W., & Michie, P.T. (2013). Stop-signal
task difficulty and the right inferior frontal gyrus. Behavioral Brain Research. 256, 205-
213.
Humphreys, G.F., & Lambon Ralph, M.A. (2014). Fusion and Fission of Cognitive Functions in
the Human Parietal Cortex. Cerebral Cortex. Advance online publication. doi:
10.1093/cercor/bhu198.
Iacoboni, M., & Dapretto, M. (2006). The mirror neuron system and the consequences of its
dysfunction. Nature Reviews Neuroscience. 7(12), 942-951.
Igelström, K.M., Webb, T.W., & Graziano, M.S. (2015). Neural Processes in the Human
Temporoparietal Cortex Separated by Localized Independent Component Analysis.
Journal of Neuroscience. 35(25), 9432-9445.
Japee, S., Holiday, K., Satyshur, M.D., Mukai, I., & Ungerleider, L.G. (2015). A role of right
middle frontal gyrus in reorienting of attention: a case study. Frontiers in Systems
Neuroscience. 9, 23
Kalbe, E., Schlegel, M., Sack, A.T., Nowak, D.A., Dafotakis, M., Bangard, C., Brand, M.,
Shamay-Tsoory, S., Onur, O.A., & Kessler, J. (2010). Dissociating cognitive from
affective theory of mind: a TMS study. Cortex. 46(6), 769-780.
Kana, R.K., Libero, L.E., Hu, C.P., Deshpande, H.D., & Colburn, J.S. (2014). Functional brain
networks and white matter underlying theory-of-mind in autism. Social Cognitive and
Affective Neuroscience. 9(1), 98-105.
Kenner, N.M., Mumford, J.A., Hommer, R.E., Skup, M., Leibenluft, E., & Poldrack, R.A.
(2010). Inhibitory motor control in response stopping and response switching. Journal of
Neuroscience. 30(25), 8512-8518.
55
Kizilirmak, J.M., Rösler, F., Bien, S., & Khader, P.H. (2015). Inferior parietal and right frontal
contributions to trial-by-trial adaptations of attention to memory. Brain Research. 1614,
14-27.
Klein, I., Paradis, A.L., Poline, J.B., Kosslyn, S.M., & Le Bihan, D. (2000). Transient activity in
the human calcarine cortex during visual-mental imagery: an event-related fMRI study.
Journal of Cognitive Neuroscience. 12(Suppl 2), 15-23.
Klintwall, L., Macari, S., Eikeseth, S., & Chawarska, K. (2014). Interest level in 2-year-olds with
autism spectrum disorder predicts rate of verbal, nonverbal, and adaptive skill acquisition.
Autism. Advance online publication. doi: 10.1177/1362361314555376
Kobayashi, C., Glover, G.H., & Temple E. (2006). Cultural and linguistic influence on neural
bases of 'Theory of Mind': An fMRI study with Japanese bilinguals. Brain and Language.
98(2), 210-220.
Kobayashi, C., Glover, G.H., & Temple, E. (2007). Children’s and adults’ neural bases of verbal
and nonverbal ‘theory of mind’. Neuropsychologia. 45(7), 1522-1532.
Korkman, M., Kirk, U., & Kemp, S. (2007). NEPSY-II: Clinical and interpretive manual. San
Antonio, TX: Harcourt Assessment.
Lai, M., Lombardo, M.V., & Baron-Cohen, S. (2014). Autism. Lancet. 383(9920), 896-910.
Leekam, S.R., Hunnisett, E., & Moore, C. (1998). Targets and cues: gaze-following in children
with autism. Journal of Child Psychology and Psychiatry. 39(7), 951-962.
Leung, R.C., Pang, E.W., Cassel, D., Brian, J.A., Smith, M.L., & Taylor, M.J. (2014). Early
neural activation during facial affect processing in adolescents with Autism Spectrum
Disorder. Neuroimage: Clinical. 7, 203-212.
Leung, R.C., Vogan, V.M., Powell, T.L., Anagnostou, E., & Taylor, M.J. (2015). The role of
executive functions in social impairment in Autism Spectrum Disorder. Child
Neuropsychology. 3, 1-9.
56
Leung, R.C., Ye, A.X., Wong, S.M., Taylor, M.J., & Doesburg, S.M. (2014). Reduced beta
connectivity during emotional face processing in adolescents with autism. Molecular
Autism. 5(1), 51.
Li, J.P., Law, T., Lam, G.Y., & To, C.K. (2013). Role of sentence-final particles and prosody in
irony comprehension in Cantonese-speaking children with and without Autism Spectrum
Disorders. Clinical Linguistics & Phonetics. 27(1), 18-32.
Libero, L.E., Maximo, J.O., Deshpande, H.D., Klinger, L.G., Klinger, M.R., & Kana, R.K.
(2014). The role of mirroring and mentalizing networks in mediating action intentions in
autism. Molecular Autism. 5(1), 50.
Lichtensteiger, J., Loenneker, T., Bucher, K., Martin, E., & Klaver, P. (2008). Role of dorsal and
ventral stream development in biological motion perception. Neuroreport. 19(18), 1763-
1767.
Lisofsky, N., Kazzer, P., Heekeren, H.R., & Prehn, K. (2014). Investigating socio-cognitive
processes in deception: a quantitative meta-analysis of neuroimaging studies.
Neuropsychologia. 61, 113-122.
Litvak, V., Mattout, J., Kiebel, S., Phillips, C., Henson, R., Kilner, J., Barnes, G., Oostenveld, R.,
Daunizeau, J., Flandin, G., Penny, W., & Friston, K. (2011). EEG and MEG data analysis
in SPM8. Computational Intelligence and Neuroscience. 2011, 852961.
Lombardo, M.V., Chakrabarti, B., Bullmore, E.T., MRC AIMS Consortium, & Baron-Cohen, S.
(2011). Specialization of right temporo-parietal junction for mentalizing and its relation
to social impairments in autism. Neuroimage. 56(3), 1832-1838.
Lord, C., Risi, S., Lambrecht, L., Cook, E.H. Jr, Leventhal, B.L., DiLavore, P.C., Pickles, A., &
Rutter, M. (2000). The autism diagnostic observation schedule-generic: a standard
measure of social and communication deficits associated with the spectrum of autism.
Journal of Autism and Developmental Disorders. 30(3), 205-223.
57
Lord, C., Rutter, M., DiLavore, P.C., Risi, S., Gotham, K., & Bishop, S. (2012). Autism
Diagnostic Observation Schedule, second edition (ADOS-2) manual (Part I): Modules 1-
4. Torrance, CA: Western Psychological Services.
Ma, L., Steinberg, J.L., Hasan, K.M., Narayana, P.A., Kramer, L.A., & Moeller, F.G. (2012).
Working memory load modulation of parieto-frontal connections: evidence from
dynamic causal modeling. Human Brain Mapping. 33(8), 1850–1867.
Marsh, L.E., & Hamilton, A.F. (2011). Dissociation of mirroring and mentalising systems in
autism. Neuroimage. 56(3), 1511-1519.
Martin, I., & McDonald, S. (2004). An exploration of causes of non-literal language problems in
individuals with Asperger Syndrome. Journal of Autism and Developmental Disorders.
34(3), 311-328.
Materna, S., Dicke, P.W., & Their, P. (2008). The posterior superior temporal sulcus is involved
in social communication not specific for the eyes. Neuropsychologia. 46(11), 2759-2765.
Matthews, N.L., Goldberg, W.A., Lukowski, A.F., Osann, K., Abdullah, M.M., Ly, A.R.,
Thorsen, K., & Spence, M.A. (2012). Does theory of mind performance differ in children
with early-onset and regressive autism? Developmental Science. 15(1), 25-34.
Mazoyer, P., Wicker, B., & Fonlupt, P. (2002). A neural network elicited by parametric
manipulation of the attention load. Neuroreport. 13(17), 2331-2334.
McCleery, J.P., Surtees, A.D., Graham, K.A., Richards, J.E., & Apperly, I.A. (2011). The neural
and cognitive time course of theory of mind. Journal of Neuroscience. 31(36), 12849-
12854.
Milner, A.D., & Goodale, M.A. (2008). Two visual systems re-viewed. Neuropsychologia. 46(3),
774-785.
Mishkin, M., Ungerleider, L.G., & Macko, K.A. (1983) Object vision and spatial vision: two
cortical pathways. Trends in Neuroscience. 6(1983), 414-417.
58
Mitchell, J.P. (2008). Activity in right temporo-parietal junction is not selective for theory-of-
mind. Cerebral Cortex. 18(2), 262-271.
Molenberghs, P., Brander, C., Mattingley, J.B., & Cunnington, R. (2010). The role of the
superior temporal sulcus and the mirror neuron system in imitation. Human Brain
Mapping. 31(9), 1316-1326.
Moradi, F., Liu, L.C., Cheng, K., Waggoner, R.A., Tanaka, K., & Ioannides, A.A. (2003).
Consistent and precise localization of brain activity in human primary visual cortex by
MEG and fMRI. Neuroimage. 18(3), 595-609.
Moriguchi, Y., Ohnishi, T., Mori, T., Matsuda, H., & Komaki, G. (2007). Changes of brain
activity in the neural substrates for theory of mind during childhood and adolescence.
Psychiatry and Clinical Neurosciences. 61(4), 355-363.
Morris, J.P., Pelphrey, K.A., & McCarthy, G. (2007). Face processing without awareness in the
right fusiform gyrus. Neuropsychologia. 45(13), 3087-3091.
Murdaugh, D.L., Nadendla, K.D., & Kana, R.K. (2014). Differential role of temporoparietal
junction and medial prefrontal cortex in causal inference in autism: an independent
component analysis. Neuroscience Letters. 568, 50-55.
Nandrino, J.L., Gandolphe, M.C., Alexandre, C., Kmiecik, E., Yguel, J., & Urso, L. (2014).
Cognitive and affective theory of mind abilities in alcohol-dependent patients: the role of
autobiographical memory. Drug and Alcohol Dependence. 143, 65-73.
Neurobehavioral Systems. (2014). Presentation: Precise, powerful stimulus delivery.
Neurobehavioral Systems, Inc. Berkley, California, United States.
http://www.neurobs.com/.
Nolte, G. (2003). The magnetic lead field theorem in the quasi-static approximation and its use
for magnetoencephalography forward calculation in realistic volume conductors. Physics
and Medicine in Biology. 48(22), 3637-3652.
Olson, I.R., Plotzker, A., & Ezzyat, Y. (2007). The Enigmatic temporal pole: a review of
findings on social and emotional processing. Brain. 130(Pt 7), 1718-1731.
59
Oostenveld, R., Fries, P., Maris, E., & Schoffelen, J-M. (2011). FieldTrip: Open Source Software
for Advanced Analysis of MEG, EEG, and Invasive Electrophysiological Data.
Computational Intelligence and Neuroscience. 2011, 156869.
Orekhova, E.V., Elsabbagh, M., Jones, E.J., Dawson, G., Charman, T., Johnson, M.H., & BASIS
Team (2014). EEG hyper-connectivity in high-risk infants is associated with later autism.
Journal of Neurodevelopmental Disorders. 6(1), 40.
Pelphrey, K.A., Mitchell, T.V., McKeown, M.J., Goldstein, J., Allison, T., & McCarthy, G.
(2003). Brain activity evoked by the perception of human walking: controlling for
meaningful coherent motion. Journal of Neuroscience. 23(17), 6819-6825.
Perner, J., Frith, U., Leslie, A.M., & Leekam, S.R. (1989). Exploration of the autistic child's
theory of mind: knowledge, belief, and communication. Child Development. 60(3), 688-
700.
Péron, J., Le Jeune, F., Haegelen, C., Dondaine, T., Drapier, D., Sauleau, P., Reymann, J.M.,
Drapier, S., Rouaud, T., Millet, B., & Vérin, M. (2010). Subthalamic nucleus stimulation
affects theory of mind network: a PET study in Parkinson's disease. PLoS One. 5(3),
e9919.
Petitet, P., Noonan, M.P., Bridge, H., O'Reilly, J.X., & O'Shea, J. (2015). Testing the inter-
hemispheric competition account of visual extinction with combined TMS/fMRI.
Neuropsychologia. 74, 63-73.
Pickering, S., & Gathercole, S. (2001). Working memory test battery for children. London, UK:
Pearson Assessment.
Porcaro, C., Medaglia, M.T., Thai, N.J., Seri, S., Rotshtein, P., & Tecchio, F. (2014).
Contradictory reasoning network: an EEG and FMRI study. PLoS One. 9(3), e92835.
Powell, J.L., Kemp, G.J., & García-Finaña, M. (2012). Association between language and spatial
laterality and cognitive ability: an fMRI study. Neuroimage. 59(2), 1818-1829.
Premack, D., & Woodruff, G. (1978). Does the chimpanzee have a theory of mind? Behavioral
and Brain Sciences. 1(4), 515-526.
60
R Core Team. (2014). R: A language and environment for statistical computing. R Foundation
for Statistical Computing. Vienna, Austria. http://www.R-project.org/.
Rabin, J.S., Gilboa, A., Stuss, D.T., Mar, R.A., & Rosenbaum, R.S. Common and unique neural
correlates of autobiographical memory and theory of mind. Journal of Cognitive
Neuroscience. 22(6), 1095-1111.
Rao, V.S., Raman, V., & Mysore, A.V. (2015). Issues related to obtaining intelligence quotient-
matched controls in autism research. Indian Journal of Psychological Medicine. 37(2),
149-153.
Reniers, R.L., Völlm, B.A., Elliott, R., & Corcoran, R. (2014). Empathy, ToM, and self-other
differentiation: an fMRI study of internal states. Social Neuroscience. 9(1), 50-62.
Richler, J.M., & Coss, R.G. (1976). Gaze aversion in autistic and normal children. Acta
Psychiatrica Scandanavica. 53(3), 193-210.
Rorden, C., Karnath, H.O., & Bonilha, L. (2007). Improving lesion-symptom mapping. Journal
of Cognitive Neuroscience. 19(7), 1081-1088.
Rothmayr, C., Sodian, B., Hajak, G., Dohnel, K., Meinhardt, J., & Sommer, M. (2011). Common
and distinct neural networks for false-belief reasoning and inhibitory control.
Neuroimage. 56(3), 1705-1713.
Sabbagh, M.A., & Taylor, M. (2000). Neural correlates of theory-of-mind reasoning: an event-
related potential study. Psychological Science. 11(1), 46-50.
Samson, D., Apperly, I.A., Chiavarino, C., & Humphreys, G.W. (2004). Left temporoparietal
junction is necessary for representing someone else's belief. Nature Neuroscience. 7(5),
499-500.
Saxe, R., & Powell, L.J. (2006). It’s the thought that counts: specific brain regions for one
component of theory of mind. Psychological Science. 17(8), 692-699.
Saxe, R., & Wexler, A. (2005). Making sense of another mind: the role of the right temporo-
parietal junction. Neuropsychologia. 43(10), 1391-1399.
61
Schmidt, A., Hammann, F., Wölnerhanssen, B., Meyer-Gerspach, A.C., Drewe, J., Beglinger, C.,
& Borgwardt, S. (2014). Green tea extract enhances parieto-frontal connectivity during
working memory processing. Psychopharmacology. 231(19), 3879–3888.
Schneider, D., Slaughter, V.P., Becker, S.I., & Dux, P.E. (2014). Implicit false-belief processing
in the human brain. Neuroimage. 101, 268-275.
Scholz, J., Triantafyllou, C., Whitfield-Gabrieli, S., Brown, E.N., & Saxe, R. (2009). Distinct
regions of right temporo-parietal junction are selective for theory of mind and exogenous
attention. PLoS One. 4(3), 1-7.
Schurz, M., Aichhorn, M., Martin, A., & Perner, J. (2013). Common brain areas engaged in false
belief reasoning and visual perspective taking: a meta-analysis of functional brain
imaging studies. Frontiers in Human Neuroscience. 7(712), 1-14.
Schurz, M., Kronbichler, M., Weissengruber, S., Surtees, A., Samson, D., & Perner, J. (2015).
Clarifying the role of theory of mind areas during visual perspective taking: Issues of
spontaneity and domain-specificity. Neuroimage. 117, 386-396.
Schuwerk, T., Schecklmann, M., Langguth, B., Döhnel, K., Sodian, B., & Sommer, M. (2014).
Inhibiting the posterior medial prefrontal cortex by rTMS decreases the discrepancy
between self and other in Theory of Mind reasoning. Behavioral Brain Research. 274,
312-318.
Serra, M., Loth, F.L., van Geert, P.L., Hurkens, E., & Minderaa, R.B. (2002). Theory of mind in
children with 'lesser variants' of autism: a longitudinal study. Journal of Child
Psychology and Psychiatry. 43(7), 885-900.
Shamay-Tsoory, S.G., Tomer, R., Berger, B.D., Goldsher, D., & Aharon-Peretz, J. (2005).
Impaired "affective theory of mind" is associated with right ventromedial prefrontal
damage. Cognitive and Behavioral Neurology. 18(1), 55-67.
Simmons, D.R., Robertson, A.E., McKay, L.S., Toal, E., McAleer, P., & Pollick, F.E. (2009).
Vision in autism spectrum disorders. Vision Research. 49(22), 2705-2739.
62
Solomon, M., Yoon, J.H., Ragland, J.D., Niendam, T.A., Lesh, T.A., Fairbrother, W., & Carter
C.S. (2014). The development of the neural substrates of cognitive control in adolescents
with autism spectrum disorders. Biological Psychiatry. 76(5), 412-421.
Sommer, M., Döhnel, K., Sodian, B., Meinhardt, J., Thoermer, C., & Hajak, G. (2007). Neural
correlates of true and false belief reasoning. Neuroimage. 35(3), 1378-1384.
Sparrevohn, R., & Howie, P.M. (1995). Theory of mind in children with autistic disorder:
evidence of developmental progression and the role of verbal ability. Journal of Child
Psychology and Psychiatry. 36(2), 248-263.
Spreng, R.N., & Mar, R.A. (2012) I remember you: a role for memory in social cognition and the
functional neuroanatomy of their interaction. Brain Research. 1428, 43-50.
Stavropoulos, K.K., & Carver, L.J. (2014). Reward anticipation and processing of social versus
nonsocial stimuli in children with and without autism spectrum disorders. Journal of
Child Psychology and Psychiatry. 55(12), 1398–1408.
Steele, S., Joseph, R.M., & Tager-Flusberg, H. (2003). Brief report: developmental change in
theory of mind abilities in children with autism. Journal of Autism and Developmental
Disorders. 33(4), 461-467.
Stone, V.E., Baron-Cohen, S., & Knight, R.T. (1998). Frontal lobe contributions to theory of
mind. Journal of Cognitive Neuroscience. 10(5), 640-656.
Stuss, D.T., Gallup, G.G. Jr, & Alexander, M.P. (2001). The frontal lobes are necessary for
'theory of mind'. Brain. 124(Pt 2), 279-286.
Taylor, P.C., Muggleton, N.G., Kalla, R., Walsh, V., & Eimer, M. (2011). TMS of the right
angular gyrus modulates priming of pop-out in visual search: combined TMS-ERP
evidence. Journal of Neurophysiology. 106(6), 3001-3009.
The MathWorks. (2014). MATLAB and Statistics Toolbox Release 2014b. The MathWorks, Inc.
Natick, Massachusetts, United States. http://www.mathworks.com/.
63
Uddin, L.Q., Iacoboni, M., Lange, C., & Keenan, J.P. (2007). The self and social cognition: the
role of cortical midline structures and mirror neurons. Trends in Cognitive Science. 11(4),
153-157.
Urbain, C., Bourguignon, M., Op de Beeck, M., Schmitz, R., Galer, S., Wens, V., Marty, B., De
Tiège, X., Van Bogaert, P., & Peigneux, P. (2013). MEG correlates of learning novel
objects properties in children. PLoS One. 8(7), e69696.
Vaidya, C.J., Foss-Feig, J., Shook, D., Kaplan, L., Kenworthy, L., & Gaillard, W.D. (2011).
Controlling attention to gaze and arrows in childhood: an fMRI study of typical
development and Autism Spectrum Disorders. Developmental Science. 14(4), 911-924.
Van Hoeck, N., Begtas, E., Steen, J., Kestemont, J., Vandekerckhove, M., & Van Overwalle, F.
(2014). False belief and counterfactual reasoning in a social environment. Neuroimage.
90, 315-325.
Van Hoeck, N., Ma, N., Ampe, L., Baetens, K., Vandekerckhove, M., & Van Overwalle, F.
(2013). Counterfactual thinking: an fMRI study on changing the past for a better future.
Social Cognitive and Affective Neuroscience. 8(5), 556–564.
van Veluw, S.J., & Chance, S.A. (2014). Differentiating between self and others: an ALE meta-
analysis of fMRI studies of self-recognition and theory of mind. Brain Imaging and
Behavior. 8(1), 24-38.
Vandenbulcke, M., Peeters, R., Fannes, K., & Vandenberghe, R. (2006). Knowledge of visual
attributes in the right hemisphere. Nature Neuroscience. 9(7), 964-970.
Vilberg, K.L., & Rugg, M.D. (2012). The neural correlates of recollection: transient versus
sustained FMRI effects. Journal of Neuroscience. 32(45), 15679-15687.
Vistoli, D., Brunet-Gouet, E., Baup-Bobin, E., Hardy-Bayle, M.C., & Passerieux, C. (2011).
Anatomical and temporal architecture of theory of mind: a MEG insight into the early
stages. Neuroimage. 54(2), 1406-1414.
64
Vivanti, G., Trembath, D., & Dissanayake, C. (2014). Atypical monitoring and responsiveness to
goal-directed gaze in autism spectrum disorder. Experimental Brain Research. 232(2),
695-701.
Vogan, V.M., Morgan, B.R., Lee, W., Powell, T.L., Smith, M.L., Taylor, M.J. (2014). The
neural correlates of visuo-spatial working memory in children with autism spectrum
disorder: effects of cognitive load. Journal of Developmental Disorders. 6(1), 19.
Vogeley, K., May, M., Ritzl, A., Falkai, P., Zilles, K., & Fink, G.R. (2004). Neural correlates of
first-person perspective as one constituent of human self-consciousness. Journal of
Cognitive Neuroscience. 16(5), 817-827.
von dem Hagen, E.A., Stoyanova, R.S., Rowe, J.B., Baron-Cohen, S., & Calder, A.J. (2014).
Direct gaze elicits atypical activation of the theory-of-mind network in autism spectrum
conditions. Cerebral Cortex. 24(6), 1485-1492.
Walter, H., Adenzato, M., Ciaramidaro, A., Enrici, I., Pia, L., & Bara B.G. (2004).
Understanding intentions in social interaction: the role of the anterior paracingulate
cortex. Journal of Cognitive Neuroscience. 16(10), 1854-1863.
Wang, S., Xu, J., Jiang, M., Zhao, Q., Hurlemann, R., & Adolphs, R. (2014). Autism spectrum
disorder, but not amygdala lesions, impairs social attention in visual search.
Neuropsychologia. 63, 259-274.
Wechsler, D. (2002). Wechsler Abbreviated Scales of Intelligence. San Antonio, Texas:
Psychological Corporation.
Weisberg, J., van Turennout, M., & Martin A. (2007). A neural system for learning about object
function. Cerebral Cortex. 17(3), 513-521.
Wellman, H.M., Cross, D., & Watson, J. (2001). Meta-analysis of theory-of-mind development:
the truth about false belief. Child Development. 72(3), 655-684.
Williams, J.H., Waiter, G.D., Gilchrist, A., Perrett, D.I., Murray, A.D., & Whiten, A. (2006).
Neural mechanisms of imitation and 'mirror neuron' functioning in autistic spectrum
disorder. Neuropsychologia. 44(4), 610-621.
65
Wyk, B.C., Hudac, C.M., Carter, E.J., Sobel, D.M., & Pelphrey, K.A. (2009). Action
understanding in the superior temporal sulcus region. Psychological Science. 20(6), 771-
777.
Young, L., Scholz, J., & Saxe, R. (2011). Neural evidence for “intuitive prosecution”: the use of
mental state information for negative moral verdicts. Social Neuroscience. 6(3), 302-315.
Zarahn, E., Rakitin, B., Abela, D., Flynn, J., & Stern, Y. (2005). Positive evidence against human
hippocampal involvement in working memory maintenance of familiar stimuli. Cerebral
Cortex. 15(3), 303-316.
Zhang, J., Hughes, L.E., & Rowe, J.B. (2012). Selection and inhibition mechanisms for human
voluntary action decisions. Neuroimage. 63(1), 392-402.
Zhang, T., Sha, W., Zheng, X., Ouyang, H., & Li, H. (2009). Inhibiting one's own knowledge in
false belief reasoning: an ERP study. Neuroscience Letters. 467(3), 194-198.
66
Appendices
A TD > ASD, FB
B ASD > TD, FB
Supplementary Figure 1 – Glass brain images from SPM depicting the TD to ASD group comparison of false
belief (A) and vice versa (B) when controlling for working memory load. The Unwitnessed-Unswitched trials
(another true belief condition) were used as the working memory control. In (A), the right superior parietal lobule,
denoted by the red arrow, is more active in TD children compared to children with ASD, as was the case when
using the Witnessed-Switched (TB) trials as the comparison. However, the inverse of this contrast (B) showed no
significant regions of activation, even though our results with the TB trials as control trials showed greater
activation in the left and right inferior frontal gyrus.