Social Cognition and the Mirror Neuron System of the Brain

Jaime A. Pineda, Ph.D.

Cognitive Neuroscience Laboratory

COGS1 class

Motivating Questions

How do our brains perceive the mental states of others despite their inaccessibility?

How do we understand the

actions, emotions and the intentions of others?

Rationally? Intuitively?

How do we understand first- and third-person experiences?

Classic Explanation

Theory-Theory (argument from analogy; disembodied

knowledge; visual hypothesis)

Involves striate, extrastriate, inferotemporal lobe and superior temporal sulcus, among others

A Different Perspective

Simulation Theory (Direct-matching hypothesis; embodied knowledge)

Map visual information onto motor representations of the same action

Mirroring systems bridges between perception

and action that allow for simulation

Mirror neurons EEG Mu rhythms

A Different Perspective

Simulation Theory (Direct-matching hypothesis; embodied

knowledge) Map visual information onto

motor representations of the same action

Mirroring systems bridges between perception and

action that allow for simulation Mirror neurons EEG Mu rhythms

The Mirror Neuron System

Iacoboni and Dapretto, Nature Reviews, 2006,7:942-951 Pineda, Beh & Brain Functions, 2008, 4, 47

Biological Motion

Visual system's ability to recover object information from sparse input

Gender Activity engaged in Emotional state

Biological Motion Perception: Monkeys

Perret and colleagues

(1989; 1990; 1994)

Cells in superior temporal polysensory area (STPa) of the macaque temporal cortex appear sensitive to biological motion

Oram & Perrett, J. Cog. Neurosci., 1994, 6(2), 99-116

Biological Motion Perception: Humans

An area in the superior temporal sulcus (STS) in humans responds to biological motion

Other areas do as well, including frontal cortex, SMA, insula, thalamus, amygdala

Grossman et al. J. Cog. Neurosci., 2000, 12(5), 711-720

Brain Circuit for Social Perception (SP)

Allison et al., Trends in Cog. Sci., 2000, 4, 267-272

• SP is processing of information that results in the accurate analysis of the intentions of others

• STS involved in the processing of a variety of social signals

Mirror Neurons

A specific class of neurons that discharge both when the monkey performs an action and when it observes a similar action done by another monkey or an experimenter

Found in: area F5 (homolog of Broca’s

area); 10-20% inferior parietal cortex (PF/7b)

Activated by: Goal directed actions

(reaching, grasping, holding) Observation of similar actions

performed by “biological” agents

Di Pellegrino et al., Exp. Brain Res., 1992, 91, 176-80

Rizzolatti et al., Cogn. Brain Res., 1996, 3:131-141

Mirror Neuron Activity

Perception-to-Action Mapping Selectivity

Action

Logically-Related(effector independent; 2X)

Congruent(effector dependent)

Perception

Understanding Intentions

Umilta et al. Neuron, 2001, 32: 91-101

Grasping Mimicking

Inferior parietal

lobule

Superior temporalsulcus

Inferior frontal gyrus

Sensorimotorcortex

Mirror Neuron System

Response facilitation Mimicry Simulation Imitation learning Understanding actions Understanding intentions Empathy Theory of Mind Language

Functional Significance

MNS activity No MNS Activity

intentionality?anthropomorphism?

biological realism?motivational significance?

transitive/intransitive actions?

generalizability?

Characterizing the System

learning?

social relevance?

Mu Rhythm

8-13 Hz oscillation over sensorimotor cortex

Normal Oscillation Self Action Observed Action

Frequency Analysis of Mu Rhythm

Power

Frequency

(8-13 Hz)

(10-14 Hz)

Pineda et al., IEEE Trans. Rehab. Engr., 2000, 8(2): 219-222

Does Mu Suppression Reflect Mirror Activity?

Baseline

Move

Observe

Imagine

Action Observation and Social Interaction

To what degree do mu rhythms, like mirror neurons, reflect social interaction?  

Oberman et al., Social Cognitive and Affective Neuroscience, 2007, 2, 62-66

Measured mu power (2 min of EEG) in normals (n=20) ages 18-34 (mean=21.1, SD=3.40 ) under different observation conditions:

Non-interacting Social Action - Spectator Social Action - Interactive Visual white noise

Engaged in continuous performance task during observation

Experimental Paradigm

Non-interacting Social Action - Spectator

Social Action - Interactive

0

0.5

1

1.5

2

2.5

3

3.5

4

Non-Interacting Social Action,Spectator

Social Action,Interactive

De

gre

e o

f S

oc

ial

Inte

rac

tio

nResults

Results

Autism Spectrum Disorder (ASD)

Problems in the following domains: Social ability Language development Behavior

Common Characteristics

Impairment in social play and imagination Impaired ability to initiate conversations with others Repetitive behaviors Impaired sustained attention Trouble Imitating others Difficulty interpreting actions and intentions of others Absence of empathy

Autism: A Dysfunctional Mirror System?

No common underlying mechanism has been identified

Deficits in imitation learning – Rogers and Pennington, 1991

Deficits in mirror neuron system - Williams et al., 2001

Hypothesis

If mu rhythms reflect MNS activity and the capacity to understand actions as well as learn through imitation, then autistics should show differences in mu rhythms compared to controls

Oberman et al., Cog. Brain Res. 2005, 24: 190-198

Experimental Paradigm

Measured mu power (2 min of EEG) in normals (n=12) and autistics (n=10) under different conditions:

Self-movement of hand

Watching video of someone moving their hand

Watching a video of a ball moving up and down

Oberman et al., Brain Res Cogn Brain Res. 2005, 24(2):190-8.

Results

Results

Oberman et al., Neuropsychologia, 2008 Jan 19 [Epub ahead of print]

Creating a Temporary “Autistic” Brain

Do sensorimotor mu rhythms reflect downstream modulation from cells in premotor cortex?

RATIONALEIf mirror neurons in IFG are involved in the direct modulation of mu rhythms, then temporary inhibition of these neurons should prevent suppression of mu rhythms and cause “autistic-like” behaviors.

Method

Measured EEG mu power in typically developing adults (n=8) under different conditions before and after IFG stimulation

Observation of movement (4 videos) Simple (hand movements) and complex (social

interactions) Baron-Cohen’s Eyes Task

Emotion and gender discrimination

1 Hz rTMS (5 min at ~ 40-50% MEP threshold) targeted at left IFG

Eyes Task

Results

0

5

10

15

20

25

30

Emotion Recognition Gender Recognition

Rea

ctio

n T

ime

(sec

)

Before IFG stimulation After IFG stimulation

0

0.2

0.4

0.6

0.8

1

Emotion Recognition Gender Recognition

Acc

ura

cy

Before IFG stimulation After IFG stimulation

Reaction Time Accuracy

Results

IFG STIMULATION

-0.1

-0.08

-0.06

-0.04

-0.02

0

0.02

0.04

0.06

0.08

0.1

C3 C4 C3 C4

SIMPLE COMPLEX

MOVEMENT TYPE

MU

SU

PP

RE

SS

ION

PRE

POST

Frontoparietal areas in an ASD brain may be underconnected

If we change the dynamics of the sensorimotor mu oscillations,

And these oscillations are functionally linked to the MNS network (IFG, IPL, STS),

Then we may change functional connectivity and recover MNS engagement,

Leading to positive changes.

IPL

STS

SM Cortex

IFG

Plasticity Induced Rehabilitation Training

Reversing Social Deficits in Autism?

Training 30 min x 3/week x 10 weeks HF ASD: 7-17 yr olds; n=20

Experimental/Control groups Mu activity above threshold (E) EMG activity below threshold

(E/C)

Pineda et al., Research in ASD, 2008

Pre/Post Assessments

Verification of diagnosis (IQ, ADI, ADOS)

Quantitative EEG (QEEG) Test of Variable Attention (TOVA) Imitation ability (Apraxia imitation test) Mu suppression index (MSI) Autism Treatment Evaluation

Checklist (ATEC) Neuroimaging (fMRI, fcMRI)

Facial Emotions (n-back) Eyes Emotion Task - ToM

Physical Causation - ToM

Mental Attribution- ToM

Pre/Post Assessments

R2 = 0.7068

0

50

100

150

200

250

300

350

400

0 2 4 6 8 10 12 14 16 18

SESSIONS

(HIT

S/M

IN)*

TH

RE

SH

R2 = 0.7673

0

50

100

150

200

250

300

350

400

0 5 10 15 20 25

SESSIONS

(HIT

S/M

IN)*

TH

RE

SH

ASD

TD

Behavioral Performance

Mu Suppression Index

MU SUPPRESSION INDEX

-0.1

-0.08

-0.06

-0.04

-0.02

0

0.02

0.04

0.06

HAND SOCIAL HAND SOCIAL

PRE-TRAINING POST-TRAINING

LO

G [

CO

ND

ITIO

N/B

AS

EL

INE

]

CONTROLS

EXPERIMENTALS

EEG Coherence

Sustained Attention

Reduction trend in ADHD score for

experimental group

Autism Treatment Evaluation Checklist

Functional connectivity

Diffusion Tensor Imaging structural

functional

Future: Neuroimaging Techniques

A Fundamental Organizational Feature of the Brain?

“Understanding others as intentional agents may be grounded

in the relational nature of our interactions with the world”

Beyond understanding actions emotions: the root of empathy? sounds and other senses language

Other problems in “mirroring” Aberrant imitation learning: addiction?

What Is It Like To Be…?

Thomas Nagel, The Philosophical Review 83 (1974).

Can aspects of subjective experience be reduced to brain activity?

Collaborators and Students

Vilayanur Ramachandran

Lindsay Oberman Eric Altschuler Andrey Vankov Bill Skinner Chulie Ulloa Brendan Allison Ed Hubbard Joe McCleery Erin Hecht David Brang Scott Carey

Adrienne Moore Rajiv Rao Chris Robinson Hanie Elfenbein Alex Bressler Steven Thurman Jena Davis Dong Suk Christa Futagaki Judith Kaye Lee Edwards Ralph-Axel Mueller Brandon Keehn

Oriana Clark Jia-Min Bai Derrick Asher Dane Chambers Matt Earhardt Heather Pelton Alicia Trigerio Albert Ayala Stephen Johnson Steve Gilmore Nick Pojman Kelly Head