Brain & Language 121 (2012) 261–266

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Brain & Language

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Short Communication

Different kinds of bilinguals – Different kinds of brains: The neural organisationof two languages in one brain

Maija S. Peltola a,b,c,⇑, Henna Tamminen a,b,c, Heidi Toivonen a,b, Teija Kujala d,e, Risto Näätänen e,f,g

a Department of Phonetics, University of Turku, FIN-20014, Finlandb Centre for Cognitive Neuroscience, University of Turku, FIN-20014, Finlandc LAB-lab, Department of Phonetics, University of Turku, FIN-20015, Finlandd Cicero Learning Network, P.O. Box 9, University of Helsinki, FIN-00014, Finlande Cognitive Brain Research Unit, P.O. Box 9, Cognitive Science, Institute of Behavioural Sciences, University of Helsinki, FIN-00014, Finlandf Centre of Functionally Integrative Neuroscience, University of Århus, Denmarkg Department of Psychology, University of Tartu, Estonia

a r t i c l e i n f o a b s t r a c t

Article history:Accepted 25 March 2012Available online 21 April 2012

Keywords:BilingualismSpeech perceptionMismatch negativity (MMN)Phonological processing

0093-934X/$ - see front matter � 2012 Elsevier Inc. Ahttp://dx.doi.org/10.1016/j.bandl.2012.03.007

⇑ Corresponding author at: Department of Phoneti20014, Finland.

E-mail address: maija.peltola@utu.fi (M.S. Peltola)

The aim of this study was to determine whether the type of bilingualism affects neural organisation. Weperformed identification experiments and mismatch negativity (MMN) registrations in Finnish andSwedish language settings to see, whether behavioural identification and neurophysiological discrimina-tion of vowels depend on the linguistic context, and whether there is a difference between two kinds ofbilinguals. The stimuli were two vowels, which differentiate meaning in Finnish, but not in Swedish. Theresults indicate that Balanced Bilinguals are inconsistent in identification performance, and they have alonger MMN latency. Moreover, their MMN amplitude is context-independent, while Dominant Biling-uals show a larger MMN in the Finnish context. These results indicate that Dominant Bilinguals inhibitthe preattentive discrimination of native contrast in a context where the distinction is non-phonemic,but this is not possible for Balanced Bilinguals. This implies that Dominant Bilinguals have separate sys-tems, while Balanced Bilinguals have one inseparable system.

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1. Introduction

Speech sound perception relies on the same general mechanismas, e.g. the perception of colours, namely the tendency to divide theperceptual space into discrete categories. Categorical perception(CP) enables the listener to focus on phonologically relevant infor-mation and disregard the redundant acoustic variation deriving, forinstance, from speech rate, gender, and age. Due to this mecha-nism, sound discrimination is accurate and reaction times (RTs)are short when a phonological category boundary is crossed,whereas within-category exemplars are difficult to discriminate(Liberman, Harris, Hoffman, & Griffith, 1957). The sensitivity peaksin the immediate vicinity of category boundaries are language-spe-cific, i.e. their acoustic locations are formed in accordance with themother tongue. These boundaries may have their roots in the na-tive language magnets, the prototypical representatives of thesound categories, which function as magnets and thus keep thecategory intact (Iverson & Kuhl, 2000). The effect of categorical per-ception was shown to have a neural correlate, a large MMN at a

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cs, University of Turku, FIN-

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category boundary (Sharma & Dorman, 1999), and the language-specificity of the memory traces governing this mechanism hasalso been established by using the mismatch negativity (MMN)component of the event related potentials (ERP) (Näätänen et al.,1997). This response is particularly suitable for studying speechsound perception, since it can capture differences in the discrimi-nation of native speech sounds (Diaz, Baus, Escera, Costa, & Sebas-tian-Gallés, 2008). In addition, it is a convenient tool for studyingthe learning of new contrasts, since its amplitude and latency re-flect discrimination sensitivity and changes in this sensitivity asa function of learning (Kujala & Näätänen, 2010). Following thesebasic findings, second language learning was shown to result inthe formation of new memory traces in immigrants who had ac-quired their second language in adulthood in an authentic environ-ment (Winkler et al., 1999), but not in classroom learners whowere exposed to a new language from the age of nine (Peltolaet al., 2003). In addition, early authentic input seems to enhancethe development of new representations (Cheour, Shestakova,Alku, Ceponiene, & Näätänen, 2002; Peltola, Kuntola, Tamminen,Hämäläinen, & Aaltonen, 2005).

A special case in speech sound perception involves bilingualism,since it entails a potential conflict in the specificity of individualsystems (for a comprehensive review, see Abutalebi, 2008).

262 M.S. Peltola et al. / Brain & Language 121 (2012) 261–266

Evidently, there is also a conflict in the research results: Chee et al.(1999) showed that early exposure to a non-native language re-sults in identically localised cortical activations during the process-ing of the two languages, and Klein, Milner, Zatorre, Meyer, andEvans (1995) suggested that late exposure has the same neuraloutcome. In contrast, Perani et al. (1996) showed that late expo-sure results in separate localisations, but that proficiency may havea more significant role in the neural organisation in comparisonwith the age of exposure (Perani et al., 1998). Kim, Relkin, Lee,and Hirsch (1997) showed that early bilinguals had the same local-isation for both languages, while later learners exhibited differentareas for the processing of their two languages, which suggeststhat there may be a difference in the neural outcome of learninglanguages in different settings. In addition to these discrepanciesin the localisation of activations in bilingual speech perception,the functional unity, or separateness has also caused confusion:Winkler, Kujala, Alku, and Näätänen (2003) measured the MMN re-sponse of immigrants in two language contexts and found that theresponses to the contrasts were identical in both language contextsdespite the fact that exposure had taken place in adulthood, whiletype of exposure was natural, whereas Peltola and Aaltonen (2005)suggested that second language learning in classroom may resultin the formation of functionally separate phonemic systems evenin learners who started learning a new language at an early age(9 years). Altogether, these studies indicate that the dichotomousclassification of bilinguals into compound (one system) and co-ordi-nate (two systems) bilinguals (Albert & Obler, 1978) on the basis ofmerely the age of exposure (AOE) may be too simplistic. However,the postulation of the term pair dominant – balanced (Albert & Ob-ler, 1978) should be studied in more detail, since it implies thatthere are two kinds of bilingual brains with dominants havingtwo separate systems and balanced a uniform one. This classifica-tion takes into consideration the proficiency level, the age of expo-sure and, most importantly, the manner in which the twolanguages were acquired, i.e. in a natural setting simultaneously,or in classroom consecutively.

The discrepancies in the findings may, in part at least, be ex-plained by two factors, namely methodological aspects and theinterpretation of the term bilingual. The methods used in questfor the neurophysiology of bilingualism have used positron emis-sion topography (PET) or functional magnet resonance imaging(fMRI) brain imaging technologies while the subjects were listen-ing to stories, producing internal speech or performing semantic-phonological tasks. In the phoneme acquisition experiments, thestimuli have been chosen with various different criteria rangingfrom the inspection of phonetic literature to extensive prior behav-ioural experiments. The subjects classified as bilinguals have in-cluded early exposed adult and child learners of a foreignlanguage, classroom learners, adult immigrants and bilingualswho have learned their two languages from birth. Certainly allthese findings add to our knowledge of bilingual speech process-ing, but the overall picture is by no means complete.

The present study compared two adult groups of bilinguals inorder to determine how the type of bilingualism, dominant or bal-anced, may result in different kinds of neural organisations. As sug-gested by Albert and Obler (1978), Balanced Bilinguals haveacquired both languages form birth in a natural ‘‘one parent –one language’’ setting. In contrast, Dominant Bilinguals have beenexposed to two languages consecutively, so that they have amother tongue and a second language that they have learned laterand possibly in a formal setting. It may, however, be the case thatthe proficiency of the original second language can reach a levelcomparable to the native language proficiency. The age of exposureand potential proficiency differences in dominant and BalancedBilinguals are a direct consequence of being a bilingual of eithersubtype; this implies that certainly the age factor has a role as well

as the proficiency aspect, but the distinction into two types of bil-inguals is a result of normal learning environments and thereforethe effects of age and proficiency cannot always be separated – itis impossible to simultaneously be a Dominant Bilingual and tohave identical age of exposure to both languages.

Theories of second language speech sound acquisition have pos-tulated that particular relations between the native and the targetlanguage phonological systems are especially difficult to acquire.Speech Learning Model (SLM) suggests that while there are someproblems with the perception of ‘‘New’’ speech sounds, the mostpersistent problems are located in speech sounds which are classi-fied as ‘‘Similar’’ to the mother tongue phonemes (Flege, 1987). Thesame idea is also presented in Perceptual Assimilation Model(PAM), which postulates that the most difficult speech soundsare those which are assimilated into one single native category(Best & Strange, 1992). In accordance with these theories, we se-lected a contrastively demanding stimulus set, i.e. an acousticclosed round vowel continuum, which is divided into two catego-ries in Finnish (/y/–/u/), but has three categories in Swedish (/y/–/

/–/u/). We performed identification experiments in both lan-guages, on the basis of which the stimuli for the oddball MMN reg-istration were selected individually for each subject. This was doneto ensure that the selected stimulus pair crossed the phonemeboundary /y/–/u/ in Finnish, but the two stimuli were located with-in the Swedish category / /. There may be inter-subject variationin the exact location of the category boundaries, so it was neces-sary to ensure individually the phonological status of the stimulito be used in the MMN registrations. As in Winkler et al. (2003)as well as in Peltola and Aaltonen (2005), we performed the sameexperiments in two different linguistic contexts. In this experi-ment, the order of these two sessions was counter-balanced andthe registrations took place at least a week apart. The DominantBilinguals were originally monolingual Finns, who were proficientin Swedish. These Dominant Bilinguals (average AOE 12.5 years)reported in a self-evaluation of language competence that theirproficiency was high both in Swedish production and comprehen-sion. This proficiency was also evaluated in a highly demandingproficiency test in the entrance examination, which only about15% of the applicants pass and are accepted to major in SwedishLanguage master’s degree programme. The proficiency level ofSwedish is quite high in Finland in general, since Swedish is theother official language in Finland and it is also a compulsory sub-ject in Finnish school curriculum. In contrast, the Balanced Biling-uals were Finnish–Swedish bilinguals from birth, and they hadused both languages concurrently. In a self-evaluation these Bal-anced Bilinguals reported a high proficiency in both languages.Our hypothesis was that behaviourally both bilingual groupsshould perceive the stimuli in accordance with the context lan-guage, but it is possible that the intermediate Swedish vowelmay interfere the boundary establishment in Finnish. If the Swed-ish phonology affects the category placement between Finnish /y/–/u/, it would suggest that there is behavioural interference formone language to another, which further suggests the possibility ofan intertwined system. When preattentive discrimination is mea-sured with the MMN, it is possible that bilinguals (either the bal-anced, the dominant or both) do not show an MMN response tothe vowel contrast when it is presented in the Swedish languagecontext (i.e. when it is phonologically irrelevant), but that the samecontrast in the Finnish context (i.e. when it is phonemic) will elicita response, which would indicate that the systems are separate.We consider this separateness to be functional, since it would im-ply that one system is inhibited in some way so that the phonolog-ical categories cannot be accessed. The other alternative would bethat the two languages are located in different areas, but this can-not be substantiated for by the EEG measurement with its limita-tions on place resolution. It can also be that top-down processing

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may explain this kind of a result, but this would be a more poten-tial explanation in the case of behavioural data (as shown in speechproduction by e.g. Videsott et al., 2010), instead of the MMN data,since preattentive elicitation may be less susceptible to top-downeffects. However, as Kiefer and Martens (2010) showed withsemantic processing and the N400 response, top-down processingmay well extent its influence on ERPs. However, this may be lesslikely on phonological processing and in our study in particular,since we are merely using isolated vowels that carry no semanticmeaning. The other possible result from our experiment wouldbe that, if the two phonological inventories are intertwined withinone system which is automatically activated by units of both lan-guages, the MMN response should be elicited in both contexts,i.e. irrespective of the phonological role of the stimulus pair in aparticular linguistic setting.

2. Results

To begin with, we analysed the identification results and fo-cused on the category boundary location and the steepness (orconsistency) of the boundary. There were no statistically signifi-cant differences between the groups in the locations of the bound-aries in either language. However, the steepness values weredifferent, since the analysis revealed the interaction betweengroup and context language (F (2,18) = 3.621, p = 0.048, seeFig. 1). Further analysis showed that this was due to less consistentidentification scores of the balanced group (mean 1.892) in com-parison with the Dominant Bilinguals (mean 1.592) in the target-ing of the Finnish boundary (F(2,18) = 4.737, p = 0.022). No othermain effects or interactions reached significant values.

We then analysed the latency of the MMN peak from the Czelectrode and the amplitude from six electrodes (Fz, Cz, F3, F4,C3, C4) from two consecutive time windows (see Table 1; Fig. 2).When the two types of bilinguals were compared, the peak latencyanalysis revealed the main effect of group (F (1,19) = 11.381,p = 0.003) suggesting a shorter latency of the MMN in the Domi-nant Bilinguals (Finnish context mean 200 ms, Swedish contextmean 223 ms) than in the Balanced Bilingual group (Finnish con-text mean 254 ms, Swedish context mean 253). This was alsoapparent in the mean amplitude analysis, which showed the signif-icant interaction between group, context language and the selected

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Bal. /y/ Bal. /u/ Dom. /y/ Dom. /u/

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Fig. 1. The identification scores from Balanced Bilinguals (thick line) and Dominant Bilinshows the vowel continuum with 18 exemplars and the Y-axis shows the times that thecategory boundary between the Finnish /y/ and /u/ was located at 8.8 (std dev 2.54) in BSwedish /y/–/ / boundary was located at 12.9 (std dev 1.23) in Balanced Bilinguals and at/u/ was at 4.6 (std dev 0.75) in Balanced Bilinguals and at 5.0 (std dev 0.60) in Dominan

time window (F(1,19) = 5.639,p = 0.028). Most importantly, therewas an interaction between group and context language(F(1, 19) = 5.369, p = 0.032), suggesting that the linguistic environ-ment had a different kind of an effect on the groups. This was ex-plained by the result that Dominant Bilinguals showed the maineffect of context language (F(1,8) = 8.843, p = 0.018), while therewas no such effect in the balanced bilingual group. No other maineffects or interactions reached significant values.

3. Discussion

Earlier studies on bilingual speech processing have indicatedthat bilinguals may have either one uniform linguistic system(e.g. Klein et al., 1995) or two separate ones with a switchingmechanism for the processing of their two languages (e.g. Garbinet al., 2011; Nakamura et al., 2010). In addition, it may be thatthe localisations of the two languages depend on the age of acqui-sition (Kim et al., 1997). These discrepancies may be caused eitherby the use of several different methods or by the various types ofbilinguals. The present study was performed in exactly the samemanner with two kinds of bilinguals, both of which can justifiablybe called bilinguals. On the basis of these new findings showingthat speech sound perception is dependent upon the linguistic con-text in Dominant Bilinguals, but not in Balanced Bilinguals, it is evi-dent that different kinds of bilinguals process their two languagesin different ways.

The behavioural results showed that Balanced Bilinguals wereless systematic in locating the Finnish category boundary. This isa clear indicator of the interfering role that the Swedish sound sys-tem has on the attention-dependent processing of Finnish speechsounds. The finding that Dominant Bilinguals showed less hesita-tion (indexed by less variability on the ability to locate the categoryboundary) at the Finnish boundary implies that – despite high pro-ficiency and the consequent ability to correctly locate the non-native boundaries – the later acquired language does not disturbthe perception of native categories. This implies that the two sys-tems are functionally separate in Dominant Bilinguals, whereasthe systems seem to be intertwined in Balanced Bilinguals. Theargued functional separation in Dominant Bilinguals in an attentiondependent task may be connected with top-down processing ordifferences in the neural organisation of the languages.

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Bal. /y/ Bal. Bal. /u/Dom. /y/ Dom. Dom. /u/

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guals (thin line) in the Finnish context (left) and Swedish context (right). The X-axissubjects identified the stimulus as a member of each category (max 10 times). Thealanced Bilingual group and at 10.1 (std dev 1.16) in the Dominant Bilinguals. The12.2 (std dev 0.94) in Dominant Bilinguals. The Swedish boundary between / / andt Bilingual group.

Table 1The average MMN amplitudes from Balanced Bilinguals and Dominant Bilinguals in two linguistic contexts as measured from six electrodes and two time windows.

Fz Cz F3 F4 C3 C4

180–230 230–280 180–230 230–280 180–230 230–280 180–230 230–280 180–230 230–280 180–230 230–280

BalancedFinnish .140 �1012 .248 �.935 .204 �.790 .087 �.792 .163 �.628 .282 �.644Swedish �.240 �.487 �.205 �.789 �.296 �.248 �.184 �.284 �.342 �.327 �.209 �.450

DominantFinnish �.938 �.504 �1033 �.444 �.810 �.458 �.966 �.654 �.956 �.496 �1049 �.650Swedish �.130 �.136 �.017 �.171 �.210 �.182 �.123 �.141 �.105 �.040 .082 �.119

Balanced Bilinguals: phonologically relevant contrast (Finnish)

Dominant Bilinguals: phonologically relevant contrast (Finnish)

Dominant Bilinguals: phonologically irrelevant contrast (Swedish)

Balanced Bilinguals: phonologically irrelevant contrast (Swedish)

F3 F4

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-2 µV

+2 µV

-100 ms

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Fig. 2. The MMN responses of the two groups in the two linguistic contexts. Balanced Bilinguals (thick lines) show a large and late MMN in both environments, whileDominant Bilinguals (thin lines) showed an early MMN of large amplitude in the Finnish context, but not in the Swedish context.

264 M.S. Peltola et al. / Brain & Language 121 (2012) 261–266

The neurophysiological results on preattentive perception sup-port the same interpretations as the behavioural results. Further-more, they indicate that the neural plastic changes caused by thetime of the second language acquisition are hard-wired, operatingin an automatic fashion. The later peaking of the MMN response inthe Balanced Bilinguals (as shown both in the latency analysisproper as well as in the mean amplitude analysis) may be seenas another indicator of the interfering effect that the two languagesimpose on each other when the systems are functionally insepara-ble. Dominant Bilinguals respond rapidly, which suggests thatthere are less exemplars (i.e. phonological categories) which needto be compared with acoustic properties of the presented stimuli.In contrast, the long latency of the Balanced Bilinguals may be anindicator of a more extensive category inventory available duringspeech sound processing, i.e. the phonological categories of bothlanguages. The finding that the amplitude of the MMN response

was context dependent in the Dominant Bilinguals, but not in Bal-anced Bilinguals, provides the most convincing evidence in supportof our interpretation of a one-store model for Balanced Bilingualsand a two-store model for the Dominant Bilinguals. In DominantBilinguals the exact same stimulus pair results in an extensive re-sponse when it is presented in the Finnish environment (i.e. whenit is phonologically relevant), but this contrast results in almost anon-existent MMN when it appears in the Swedish context (i.e.when it has no phonological relevance). This shows that DominantBilinguals are able to block the attention-independent perceptionof their native speech sounds, when they consider it to be a partof a non-native inventory, which suggests that the maternal Finn-ish phonology can be ‘‘switched off’’ in accordance with therequirements of the Swedish language context. This further impliesthe existence of two functionally separable phonological systems.This argument is made even stronger by the fact that the blocked

M.S. Peltola et al. / Brain & Language 121 (2012) 261–266 265

language was the mother tongue, which continues to be the pri-mary language, but still its phonological system can be disre-garded. The functional separation of the systems in DominantBilinguals may be induced by inhibition effects, top-down controlor even distinct cortical areas involved in the processing of thetwo languages. The finding that Balanced Bilinguals showed simi-lar MMNs in both contexts, indicates that the linguistic environ-ment had no role in preattentive perception, i.e. in the retrievalof memory traces. This clearly shows that, for Balanced Bilinguals,the two systems are so intertwined that exemplars from bothinventories are automatically activated regardless of the languagecontext. Taken together, preattentive processing is clearly relatedto the type of bilingualism: Balanced Bilinguals cannot keep thetwo languages apart, while Dominant Bilinguals can block one lan-guage so that it becomes inactive even in preattentive processing.

On the basis of both the identification and MMN results, we ar-gue that Balanced Bilinguals have one uniform speech sound sys-tem for the processing of their two maternal languages, whereasDominant Bilinguals have two separate phonological inventories.This interpretation may easily be seen as the evident outcome ofthe manner in which the languages were acquired: Dominant Bil-inguals learned the languages consecutively so that there were dis-crete environments where the languages needed to be used (homevs. language lessons), while Balanced Bilinguals acquired the lan-guages simultaneously in an environment where both were uti-lised all the time. It may be that the different types of demandsimposed by the learning settings trigger different kinds of storagemodels.

4. Methods

Group 1 consisted of 12 balanced Finnish–Swedish bilinguals(age range 16–31, mean 20.3 years, 7 females), who had acquiredboth languages from birth at home and had continued using bothlanguages in their everyday lives. Self-evaluations of language pro-ficiency showed that these Balanced Bilinguals had a high profi-ciency of both their maternal languages. None of these subjectshad lived in Sweden. The subjects in Group 2 were all advancedFinnish University students of Swedish (age range 20–24, mean20.2 years, 6 females), who had obtained a high command of Swed-ish. The high proficiency level was guaranteed by highly demand-ing entrance examinations before entering the Department ofSwedish Language at the University of Turku. In addition, all sub-jects had studied Swedish as their major minimum 2 years beforeparticipating in the present experiment. At the Department ofSwedish Language, only Swedish is used, so the everyday exposurewas high as well. The average AOE was 12.5 years. All subjectswere right handed (tested with Edinburgh Handedness Inventory)and they had normal hearing (tested prior to the experiment withperceptually relevant frequencies 250 Hz, 500 Hz, 1000 Hz,2000 Hz and 4000 Hz). The subjects in both groups participatedin the experiment twice, so that only one language per sessionwas used (the data were collected by two researchers), and the or-der of the sessions was counterbalanced. In other words, half of thesubjects were first contacted by a native speaker of Swedish, whothen arranged the laboratory schedules, conducted the backgroundinquires (handedness, language background etc.) and finally con-ducted the experiments in the laboratory so that only Swedish lan-guage was used. A week later, these subjects performed the testswith a native Finnish speaker so that only Finnish was used duringthe session. Otherwise the test sessions were identical. Also, therewas at least a week between the two sessions.

The stimuli for the behavioural identification experiment con-sisted of isolated vowels (synthesised using HLSyn software, 1.0.Sensimetrics, Inc.) from the closed rounded vowel continuum.The continuum contained 18 vowel stimuli, where the second

formant (F2) value varied from 703 Mel to 1553 Mel (606–2077 Hz) with 50 Mel steps. The values for F1, F3 and F4 were250 Hz, 2600 Hz and 3500 Hz, respectively. The F0 contour imi-tated the natural fundamental frequency and thus started from112 Hz, ascended to 132 Hz at 100 ms and descended to 92 Hzby the end of the stimulus, i.e. by 350 ms. The continuum hastwo discrete categories in Finnish (/y/–/u/), but three in Swedish(/y/–/ /–/u/).

In the forced choice identification experiments, subjects wereasked to identify the vowel stimuli in accordance with the phono-logical system of the context language. The subjects heard eachstimulus 10 times in a random order. They were instructed to pressa numpad button as soon as they heard the stimulus; with this but-ton press they identified the stimulus as either /y/ or /u/ on theFinnish session and /y/, / / or /u/ in the Swedish session. In thismanner, we were able to obtain individual category boundary loca-tions for both languages by subjecting the data to logit transforma-tion analysis using SPSS statistical analysis software. The analysisindicates the cross-over point in the continuum (i.e. the pointwhere the distribution of answers is 50%) and simultaneously itprovides the steepness value for this cross-over point (i.e. the con-sistency at which the subject was able to locate the boundary andalso when group averages were calculated, the consistency atwhich the group as a whole was able to locate the boundary).The steepness value was calculated so that we selected the maxi-mum point (i.e. the point where all subjects identified the stimulus10 times as belonging to a particular category) and the minimumpoint (i.e. the stimulus which none of the subjects identified asbelonging to that category) and the logit transformation providedthe steepness value for this curve. For example, steepness of thecross over point between Swedish context /y/ and / was deter-mined so that we selected the stimulus that was identified 100% as/y/ and the stimulus which was considered 0% /y/ and 100% / /,and then the logit analysis revealed the steepness of the connect-ing line. This data were then statistically analysed separately forthe two variables (location and steepness) by a Group (2) x Contextlanguage (2) Repeated measures analysis of variance (ANOVA).After the discovery of the significant interaction between Groupand Context language of the steepness value analysis, we per-formed further post hoc tests to discover the cause of thisinteraction.

On the basis of the identification data, we selected the stimuluspair for the MMN registration individually for each subject so thatit crossed the phoneme boundary /y/–/u/ in Finnish, but was with-in the Swedish category / /. The stimulus representing /y/ func-tioned as the standard and / / was the deviant. We registeredEEG in the oddball paradigm (ISI 550 ms, deviant probability0.13, 783 standards, 120 deviants; the standards following a devi-ant were excluded from the analysis) with Sn electrodes (Electro-Cap International, Inc.) using Synamps amplifier (sampling rate250 Hz; bandwidth 0.5–70 Hz). Eye movements were monitoredwith two electro-oculograms and impedance was kept under5 kO. The EEG was then filtered off-line (bandpass 1–30 Hz, arte-fact criterion at ±100 lV, epoch 600 ms including a 100 ms presti-mulus baseline). The separately averaged waveforms for thestandard and the deviant stimuli were computed for each subjectand the difference waveforms were then created by subtractingthe standard response from the response to the deviant stimulus.During registration the subjects sat in a comfortable armchairwatching a silent unsubtitled movie of their choice. We analysedthe MMN latency from the Cz electrode with one long Time win-dow (150–300 ms). The mean amplitude was determined fromFz, Cz, F3, F4, C3 and C4 electrodes with two consecutive time win-dows (180–230 ms and 230–280 ms) centred around the MMNpeak maxima. The latency data were subjected to a Group (2) xContext language (2) ANOVA analysis and the amplitude data to

266 M.S. Peltola et al. / Brain & Language 121 (2012) 261–266

a Group (2) x Context language (2) x Time window (2) x Electrode(6) Repeated measures analysis of variance (ANOVA). Further posthoc tests were used to determine the cause for the interaction be-tween Group and Context language.

Acknowledgments

This work was financially supported by the Academy of Finland(Project Numbers 206352, 128840, and 122745) and Emil AaltonenFoundation. We wish to thank Jyrki Tuomainen, PhD for his valu-able help at the beginning stages of this Project and Ms. Heli Kurt-tila, Jaana Hirvelä, M.A. and Laura Salonen, M.A. for their assistancewith data collection and analyses.

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