LANGUAGE DEVELOPMENT IN BILINGUALLY-EXPOSED
CHILDREN WITH AUTISM SPECTRUM DISORDERS
Reasoned Speculations about the Influence of Bilingual Exposure on the Executive Functioning
Skills in Children with Autism Spectrum Disorders
By Kacper Krzysztof Sulak
Thesis submitted in partial fulfilment of the requirements for the degree of
Master of Arts in General Linguistics
At
UNIVERSITY OF AMSTERDAM
Graduate School of Humanities
July 2013
Supervisor:
Dr. Jan de Jong
Second Reader:
Dr. René Genis
MA Thesis 2013
Kacper Sulak
Table of Contents
Acknowledgement ........................................................................................................................................ 2
1.
Introduction .......................................................................................................................................... 3
2.
Bilingualism ........................................................................................................................................... 7
3.
2.1.
Language Development in Typically-Developing Bilingual Children .................................. 8
2.2.
Bilingualism: Harmful or Beneficial? ...................................................................................... 10
2.3.
Language in Bilingual Children with Developmental Disorders ........................................ 11
2.3.1.
Bilingualism in Children with Down’s syndrome ......................................................... 13
2.3.2.
Bilingualism in Children with Specific Language Impairment.................................... 14
Autism Spectrum Disorders ............................................................................................................. 15
3.1.
Language in Monolinguals with ASD ..................................................................................... 16
3.2.
Autism-Related Factors Which Potentially Limit Bilingual Learning ................................ 18
3.3.
Language in Bilingually-Exposed Children with ASD ......................................................... 19
3.3.1.
Lexical Skills ....................................................................................................................... 20
3.3.2.
Early Language Milestones .............................................................................................. 22
3.3.3.
Language Characteristics in Toddlers ............................................................................. 26
3.3.4.
Language and Literacy ...................................................................................................... 27
3.4.
4.
5.
Findings and Limitations .......................................................................................................... 28
Executive Control .............................................................................................................................. 31
4.1.
Executive Control in Typically-Developing Bilinguals ........................................................ 32
4.2.
Executive Dysfunctions ............................................................................................................ 34
4.3.
Possible Effects of Bilingual Exposure on the EF Skills in Children with ASD ............. 36
Conclusions ......................................................................................................................................... 38
Bibliography ................................................................................................................................................ 40
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Acknowledgement
The writing of this thesis has been one of the most important academic challenges I have
ever had to face. Without the support, guidance, and patience of the following people, it would
never have been completed. It is to them that I owe my profound gratitude. I would like to
express my very great appreciation to my supervisor Dr. Jan de Jong for his valuable and
constructive suggestions, and motivation while writing this thesis. His willingness to give his time
so generously has been very much appreciated. I am also particularly grateful for the time and
assistance given by Dr. René Genis who very kindly agreed to review my thesis and participate in
the thesis defence. I would like to offer my special thanks to Dr. Jo van Herwegen from
Kingston University for her constructive criticism and witty comments.
My special thanks are extended to the staff of the Centre for Children and Adolescents
with Autism in Gdańsk who taught me “how to teach children with autism to live among us”. I
would also like to express my gratitude to Katarzyna Radtke-Michalewska who introduced me to
the “world” of speech and language disorders and shared with me her professional experiences
and observations. This study is dedicated to my beloved godmother Małgorzata Rybicka. She is a
wonderful person whose work and devotion in raising awareness of autism in Poland inspired my
academic interests and made me sensitive to how different yet amazing people with autism are.
Finally, I would like to thank my family and friends who have supported and motivated me all the
way while completing this thesis.
Amsterdam, July the 26th, 2013
Kacper Sulak
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1. Introduction
Approximately half of the world’s population speaks more than one language (Kremer-Sadlik,
2005). Moreover, early second language education is becoming a common language policy in the
Western countries (Calabrese & Dawes, 2008) as multilingual environments are becoming
increasingly prevalent worldwide (Valicenti et al., 2012). In the contemporary culture, bilingualism
has become a lifestyle, an advantage on the labor market, but also a necessity in the countries
where more than one language is spoken (e.g. Switzerland, Belgium, and India) (Kremer-Sadlik,
2005). From a layman’s point of view, bilingualism could be described as a capacity of speaking
and comprehending more than one language. While the previous description is not wrong, it fails
to account for the complexity of bilingualism as a sociocultural phenomenon and a socialpsychological behavior. It is crucial to realize that exposure to two languages not only implies
dealing with two language systems, but also with two sets of social interaction, which
subsequently leads to establishing intricate cognitive strategies. What is striking, bilinguals,
especially the ones who were exposed to two languages from a very early age, have been found to
have some linguistic and cognitive advantage over their monolingual peers. Many researchers
have recently stressed the beneficial effects of a bilingual up-bringing including its supposed
inhibiting effect on the onset of senile dementia (Bialystok, 2007).
In bilingual populations, typically-developing (TD) children have been found to follow the
same progression through acquisitional milestones (or language milestones) as their monolingual
age peers, but they may somewhat lag behind their monolingual peers in the further language
development (Paradis, 2010; Paradis et al., 2007; Allman; 2005; Nicoladis et al., 2012), since they
are exposed to quantitatively less rich input, as they have to divide it into two languages
(Unsworth et al; 2011). Nevertheless, bilinguals seem to benefit from the dual language learning
experience, as it provides linguistic and cognitive “boosts” (Marian et al., 2009), because they
have to constantly shift between two language systems and inhibit cues from the language that is
irrelevant to the social setting. Such ‘mental training’ has been argued to increase executive
control abilities in bilinguals (Bialystok et al., 2009).
However, it is important to realize that, just like in monolingual populations, many children
raised in bilingual families are born with developmental disorders (DD) which, in various ways,
delay and/or impair their language and cognitive development. These days, clinicians or speech
and language therapists who work with these children, sometimes advise their parents to stop
speaking two languages at home because it may “confuse” the children and, as a consequence,
lead to additional delays in language development(Kremer-Sadlik, 2005; Yu, 2013).
These
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children are much more dependent on language input when they are developing their first and/or
second language (Toppelberg et al., 1999), and thus, the use of high-quality “one-language” input
is argued to much more likely to improve their language outcomes (Kohnert et al., 2005; Paradis,
2007; Thordardottir, 2002).
Paradoxically, some developmentally delayed children who, despite professional’s advice,
have been exposed to more than one language, have been found to reach the same language
levels as their monolingual peers with the same disorders (Paradis et al., 2003; Kay-Raining Bird
et al., 2005). Studies including participants with specific language impairment (SLI) found no
significant difference between bilingual and monolingual children, with regard to their language
(deficits) profiles (e.g. Paradis et al., 2003). Moreover, studies of participants with Down’s
syndrome showed that bilingual children with this disorder presented the usual profile of
weaknesses relative to the error profile of the mental-age-matched typically-developing bilingual
controls (e.g. Kay-Raining Bird et al., 2005). These findings offer promising or even comforting
predictions for children affected by such disorders. However, still very little has been said about
the language development of children with Autism Spectrum Disorders (ASD) who are raised in
bilingual environments. It could be due to the fact that the social symptoms of ASD receive
much more attention during intervention than the language impairment in this disorder or
because language profile is so varied in this disorder. It may also be due to the fact that
individuals with ASD have particular problems with social interaction. Growing up in a bilingual
environment implies dealing with two languages, but, at the same time, with two sets of social
interaction. Since people with ASD already present with deficits in language and social interaction
in the monolingual populations, it is likely that dual language learning and exposure to two sets of
social interaction could potentially aggravate their language development (Hambly & Fombonne,
2012).
This issue is actually a fairly under-researched topic and only received some attention during
the past few years. Even though the extent to which bilingually-exposed children with ASD
acquire language is still unclear, research evidence of studies to date suggest that they acquire
language up to the same levels of competence as their monolingual peers with ASD (Hambly &
Fombonne, 2012; Petersen et al., 2012). Therefore, it is necessary to extensively discuss the
findings of those studies, consider their limitations and subsequently offer some new research
which could provide a clearer and more comprehensive profile of this population. This could
ultimately allow for predicting functional and language outcomes of these children and establish
an individualized intervention strategy for them. More importantly, cognitive aspects of
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bilingualism need to be taken into consideration: some children with ASD have severe cognitive
deficits and present with executive dysfunction (Ozonoff et al., 1991). Executive dysfunction is a
disruption to the efficacy of a group of cognitive processes that regulate, control and manage
other cognitive processes that play an important role in day-to-day social interaction and
functioning in a society (Elliott, 2003). For instance, people with ASD may have trouble with
dividing their auditory attention (Kenworthy et al., 2009), so they may not listen to what is being
said to them, but attend to the background noise, which makes conversing with them particularly
difficult.
At the same time, typically-developing bilinguals have been found to present with increased
executive functioning abilities which are said to result from exposure to two (or more) languages
at the early stages of language development (Bialystok et al., 2009). Keeping this in mind, it is
tempting to suggest that children with ASD will benefit from bilingual exposure, which would
compensate some of their cognitive impairments. Studies of populations with other
developmental disorders have shown that some bilingually-exposed children have an advantage in
the executive control tasks compared to their monolingual peers (Paradis, 2010; HermodsonOlsen, 2012). Therefore, it is worth considering that the same predictions could apply to
bilingually-exposed children with ASD. It is plausible that “cognitive training” by exposure to
two languages could increase cognitive abilities of these children and subsequently compensate
the effects of executive dysfunction which hinder their day-to-day social interaction.
The following review focuses on the interdependence and the interplay of the effects of three
cognitive entities: bilingualism, ASD and executive control. The first chapter will define the
notion of bilingualism, and present three theoretical accounts explaining this phenomenon.
Furthermore, the course of normal language development in bilingual children will be outlined,
followed by a brief presentation of some research evidence provided by the studies investigating
language outcomes in bilingual populations with developmental disorders. The second chapter is
devoted to the discussion of ASD as a language disorder. In the first place, language deficits
characteristic of ASD are specified, and, subsequently, results of the very recent studies regarding
language development in bilingually-exposed children with ASD are presented. The chapter
concludes with a discussion of limitations and constraints on these studies as well as suggestions
for future research. In the final chapter, a review of the studies discussing increased executive
control in typically-developing bilinguals is juxtaposed with a description of the executive
dysfunction profile in ASD. These considerations are concluded with some reasoned speculations
about the effect of bilingual exposure on the executive functioning abilities in people with autism
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spectrum disorders: some bilingually-exposed children with ASD would have increased executive
control abilities which would compensate for some of the effects of executive dysfunctions.
Contrasting evidence is provided by the research findings of the studies regarding populations
with other developmental disorders. Finally, with regard to these predictions, new research
objectives are proposed and factors which need to be taken into account in future research are
specified.
It has been agreed that children exposed to two languages may somewhat lag behind their
monolingual peers (Paradis, 2010; Paradis et al., 2007; Allman; 2005; Nicoladis et al., 2012), since
they are exposed to quantitatively less rich input, as they have to divide it into two languages
(Unsworth et al; 2011). Therefore, it is likely that bilingually-exposed children with developmental
disorders would show additive effects of disorder and of bilingualism on their language delay. In
the present review, two hypotheses about the effects of bilingual exposure in ASD are
entertained. First of all, it is contended that exposure to two languages would not have a delaying
effect on language development. Even though it is plausible that children with developmental
disorders could show additive effects of disorder and bilingualism, it is expect that this would not
lead to a disproportionate language delay in these children, compared to their monolingual peers
with the same disorders. Evidence from the studies discussed in this paper will be used to
support this assumption. Secondly, since it is expected that bilingual exposure is not a gross
liability to language development, it is further anticipated that it may actually have a compensating
effect on the executive dysfunctions in ASD; namely, that some children with ASD may benefit
from being bilingually-exposed and present with increased executive control abilities, because
interacting with two languages would act as a form of cognitive “exercise”. Using two different
languages requires quick attention-shifting, inhibiting irrelevant cues, and planning (Kovacs,
2009), therefore, in bilinguals, these abilities have been found to be increased (Bialystok &
Martin, 2004; Kroll et al., 2008). The following speculation will be reasoned by research findings
of studies into the effects of bilingualism on cognitive functioning
abilities of
neurodevelopmentally vulnerable children, and children with SLI.
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2. Bilingualism
In the simplest possible words, a bilingual could be described as an individual who “acquired
native-like control of two languages” (Bloomfield, 1933: 56). However, being bilingual implies
much more than speaking two languages on a native-like level. The presented view does not only
limit the number of people who could be recognized as bilinguals, but also its definition of
bilingualism makes it difficult to operationalize the notion of “native-like fluencies” (Butler &
Hakuta, 2004). A much broader definition proposed by Haugen describes a bilingual as an
individual who acquired fluency in one language, but who is also able to produce complete and
meaningful utterances in another language (1953), as he (Haugen) realises that acquiring a nativelike proficiency in two languages is an arduous task. This view is frequently used by researchers in
formulating their own definitions of bilingualism (Hakuta, 1986; MacNamara, 1967; Valdés &
Figueroa, 1994), since it takes into account the possible variability in bilinguals’ first and second
language proficiencies. In that way, even second language learners at the early learning stages
could be classified as bilinguals (Butler & Hakuta, 2004). Finally, Butler and Hakuta (2004)
characterise bilingualism in terms of communicative abilities. In their view, bilinguals acquire
communicative skills, with various levels of proficiency, in language and literacy, so that they are
able to interact with speakers of more than one language in a given society.
Indeed, there is no unanimous definition of bilingualism which could simply explain this
concept. It is however clear, that bilingualism is not merely “two-language-ness”, but a complex
psychological and sociocultural behavior with multidimensional aspects, thus it can be explained
in a number of ways. For instance, Hakuta et al. (1987) propose a three-way distinction for
bilingualism:

When bilingualism is characterized in terms of processing and cognitive abilities, we tend
to speak of cognitive bilingualism. Within the construct of this approach, bilinguals are
defined as individuals who possess two linguistic systems, and the approach aims to
explain how these two systems fit into the mind of an individual, and how they are
represented conceptually and neurologically. The variables of interest in cognitive
bilingualism are the levels to which individuals acquire mastery of the two languages and
the cognitive processes in which the languages are engaged.

On the other hand, when bilingualism is seen as a feature of the social condition and
affect of the individual, we define it as social psychological bilingualism. The social
psychological account concentrates predominantly on the social correlates of the two
languages. The linguistic aspects of bilingualism are much less emphasised within the
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scope of this approach, so, for instance, grammatical qualities of languages are of
marginal importance. What does matter is how the languages convey group affiliation to
the bilingual individuals.

Finally, the approach which concerns the between-group interactions is classified as
societal bilingualism. Within this account, bilingualism is characterised as a societal entity,
and “the two languages serve as a symbol over which interaction occurs” (Hakuta et al.,
1987). Similarly to social psychological accounts, in this perspective, language serves a
symbol of membership in a group, but more importantly, maintains group’s identity and
cohesiveness. The societal approach is also much less concerned with within-group
differences or with how the grammar and form of the two languages are sustained in the
groups.
Since the later considerations focus on the possible influence of bilingual exposure on
language development in ASD, the cognitive approach seems to offer the most corresponding,
“clinical” means for characterising bilingualism. It is however crucial to keep in mind that ASD
does not only involve a delay in linguistic and cognitive development, but also life-long social–
interaction impairment. Therefore, explanations offered by societal and social psychological
approaches also need to be taken into account when discussing the following issue.
2.1.
Language Development in Typically-Developing Bilingual Children
From the above discussion, one can draw the conclusion that being bilingual does not simply
boil down to understanding and speaking more than one language; it not only implies possessing
two linguistic systems, but also having knowledge of two different sets of social interaction.
Clinicians and language specialists are often asked whether exposing children to such diverse
input would confuse them and, as a consequence, delay their development. For all we know,
typically-developing children exposed to two languages develop similarly to their monolingual
peers, though somewhat later and/or slower. However, some distinctions need to be made with
regards to the timing of bilingual exposure (Fierro-Cobas & Chan, 2001). The one of most
agreed-upon typologies of bilingualism, which focuses on the age of exposure to two (or more
languages), distinguishes between early – simultaneous bilinguals, and late – successive bilinguals1
(Genesee et al., 1978). The first acquisition pattern – simultaneous bilingualism, regards children
who typically acquire two languages (from birth) before the age of 3;0. The second pattern –
successive (or sequential) bilingualism, regards children who acquire their second language by age
Unsworth et al. (2011) also add a group of early successive bilinguals (ESB), who are exposed to two languages
between the 1st and the 4th year of life.
1
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of 3;0 after having acquired their first language (Fierro-Cobas & Chan, 2001), however,
successive bilinguals often to begin learning their second language at school entry. For instance,
children from immigrant families speak a minority language at home and learn the majority
language at school (Paradis, 2010). Therefore, maturational and schooling differences are taken
into account when predicting the ultimate attainment in second language proficiency. In general,
it is believed that the earlier the age of second language acquisition, the better the second
language proficiency (Genesee et al., 1978), but it has also been found that early bilingual
exposure has positive or facilitating effect on cognitive development of children (Hakuta & Diaz,
1985; Kapa, 2010).
Simultaneous language acquisition is different from first language development in
monolingual children. In the course of simultaneous acquisition, bilinguals go through two stages
of language development: a stage of undifferentiated “single-language” system and a
differentiated stage (Fierro-Cobas & Chan, 2001). From birth up to the age of 3;0, language is an
undifferentiated system which is composed of elements from both languages of exposure. First
words may be produced slightly later than in monolinguals, but, as reported by Paradis et al.
(2003), the age of their appearance still falls within normal range. In general, simultaneous
bilinguals follow the same progression through language milestones as their monolingual age
peers. The same developmental processes that occur in monolingual acquisition, also occur in the
undifferentiated stage of simultaneous bilingualism, but in the latter two languages are involved in
those processes. Languages are differentiated and used as separate systems around the age of 4;0,
but before that, simultaneous bilinguals tend to blend and mix two languages; they may inflect
words from one language with affixes from the other language or use words from both languages
in one sentence (e.g. Batoreo, 1998). In the differentiated language stage, children begin to
associate each language with specific people or situations, then, gradually come to realise that two
different languages are being used, and, ultimately, learn to consciously and effectively codeswitch, as they come to recognize different language settings or specific contexts (Fierro-Cobas &
Chan, 2001).
On the other hand, up to the moment of exposure to a second language, successive
bilinguals are basically following the typical stages of monolingual language acquisition. However,
the way in which their second language develops is not exactly the same as in their first language.
First of all, successive bilinguals have already some prior knowledge derived from acquiring their
first language; for instance, they may have already developed some prototypes and categories
(Casasola & Bhagwat, 2007). More importantly, the rapidity by which another language is
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acquired varies across children and depends on individual differences, such as motivation or
temperament (Fierro-Cobas & Chan, 2001). Finally, the amount and quality of language input
essentially affects the extent to which a child is going to be proficient in the second language.
Successive bilinguals are rather unlikely to be exposed equally to both languages, and so, to
become balanced bilinguals (showing the same proficiency in both languages).Therefore, the
language in which they feel most comfortable, but not necessarily their first language, becomes
the dominant one (Fierro-Cobas & Chan, 2001). However, with respect to acquisitional tempo,
both simultaneous and successive bilinguals follow the same progression through language
milestones as their monolingual peers, the timing of bilingual exposure and the amount of
language input critically influence the extent to which children become proficient in two
languages.
2.2.
Bilingualism: Harmful or Beneficial?
Interestingly, until the end of the first half of the past century it was widely believed that
bilinguals may suffer from a so-called “language handicap”, and that bilingualism had negative
effects on the cognitive abilities of typically-developing children (MacNamara, 1967). However,
nowadays it is widely believed that bilingualism does not lead to such profound deficits during
language development. For instance, bilingual a recent study by Pena et al. (2009), which included
a sample of over 1200 preschool children who were exposed to varying amounts of English and
Spanish, provided convincing evidence that growing up bilingually does not increase the risk for
language impairment. Spanish-English bilinguals who were compared with English and Spanish
monolingual controls were screened in the domains of semantics and morphosyntax in both
Spanish and English. Even though the scores of bilingual children were considerably lower to the
scores of their functional monolingual peers, they were no more likely to fall in at-risk range,
based on the performance on the testing sets. Factors such as exposure to the second language
and maternal education were weakly associated with risk for language impairment, but not with
language group.
The research developments of the past five decades have shown that, contrary to previous
assumptions, growing up bilingually may have positive effects on linguistic and cognitive abilities
(Bialystok, 2001). Nair and Bhat (2013) even dare to argue that bilingualism should never be
considered a disadvantage, as it positively influences certain cognitive processing skills and
enriches socially and culturally. Thus, it is no surprise that Toppelberg et al. (1999) stress that
every typically-developing child, if possible, should be exposed to two or even more languages. It
is crucial to stress here that even though bilinguals and monolinguals show very little difference
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in their progression through linguistic milestones, there are other substantial differences between
these two groups. As previously stated, bilinguals have been argued to have some linguistic
advantage over monolinguals: children who are brought up bilingually are said to develop
understanding of taxonomic relationships in the lexicon earlier than their monolingual peers
(Sheng, McGregor, & Marian 2006), and bilingual adults were found to be better at learning new
words than monolingual adults, since the former group is argued to make use of a variety of
word-learning strategies with similar efficiency whereas the latter performed significantly worse
on the same task (Kaushanskaya & Marian, 2009). What is even more interesting, bilingualism has
been argued to be associated with a wide range of cognitive advantages (Diaz, 1985). For
instance: bilingual children have been found to exhibit superior performance in meta-cognitive
skills such as figure-ground discrimination or divergent thinking (Bialystok, 2001; Cummins,
1976); and they are also said to be better than monolinguals at inhibiting irrelevant verbal or nonverbal information – that ability is said to be slower to decline with age in bilinguals (Salvatierra &
Rosselli, 2011). Finally, bilingualism has been suggested to act as a protection mechanism which
buffers against the onset of Alzheimer’s disease (Bialystok et al., 2007).
The effects of
bilingualism on cognitive abilities will be discussed more extensively in the final chapter of this
paper.
2.3.
Language in Bilingual Children with Developmental Disorders
The previous section outlines the course and characteristics of typical language development
in simultaneous and successive bilinguals. Furthermore, linguistic and cognitive differences
between monolingual and bilingual groups were highlighted. Even though research evidence is
strong enough to contend that typically-developing bilingual children, just like their monolingual
peers, follow a timely progression through language milestones, and that they are unlikely to run
into any serious difficulties regarding bilingual exposure, it is still a matter of dispute whether the
same should apply to the children with developmental disorders, since their control of either
language, leaving aside bilingualism, is rarely attainable (Toppelberg et al., 1999).
In most of the developmental disorders (DD), language ability is said to be a reliable
predictor of functional outcome (Toppelberg et al., 1999; Nordin & Gillberg, 1998). TagerFlusberg and Sullivan (1997) argue that there is a strong correlation between language abilities
and social functioning and adaption in disorders such as autism spectrum disorders (ASD),
specific language impairment (SLI), and Down’s syndrome (DS). With regard to language
disability, developmental disorders can be divided into disorders with primary language effects,
and secondary language effects. Primary language disorders are generally described as language
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difficulties in the absence of any other impairments or disorders which could be held responsible
(Justice, 2006). A classic example of primary language disorder is SLI. On the other hand, in
secondary language disorders, language difficulties arise as a consequence of another disorder
(Justice, 2006). ASD and DS are considered to be typical instances of secondary language
impairments. The following discussion of language development in bilingually-exposed DD
populations will focus on evidence from SLI and DS. The former group was chosen due to the
fact that SLI is a classic example of a DD with language deficits that do not stem from another
disorder. Bilingual children with SLI have been suggested to have some cognitive advantage over
their monolingual peers with SLI, while having a severe language handicap (Paradis, 2007; Engel
de Abreuet al., 2013). This fact will become a crucial argument in the later considerations about
possible effects of bilingualism on the executive control of children with ASD. In addition, DS,
like ASD, is a disorder with secondary language effects. This chapter will focus on language
development of bilingually-exposed children with autism, and research findings from the studies
of SLI and Down syndrome will be used to support the further considerations.
Children with different developmental disorders present various language profiles; some
may present with deviant language, others with language delays (Bernstein Ratner, 1997).
However, professionals who work with these children need to be aware that, in general, capacities
of processing and organizing language input according to specific rules are impaired in those
children. They depend on language input much more than TD children; therefore, much greater
attention needs to be paid to the quality and quantity of language input that children with
developmental disorders receive – language needs to be modified (or even simplified) in order to
provide them with high-quality input which would maximise the contrasts between various
language features (Toppelberg et al., 1999).
What needs to be stressed here is that developmental disorders pose a challenge not only
to children affected by them, but also to their families. This problem may appear to be even more
complex when more than one language is spoken at home. When a child from a bilingual family
is diagnosed with a developmental disorder, parents often begin to wonder about the impact of
bilingual exposure. Language specialists report that parents often ask if bilingual exposure from
birth may lead to additional developmental delays in language; whether their child should be
exposed to a second language if it already shows delays in the first language; and whether they
should speak to their child in their home or heritage language (Fierro-Cobas & Chan, 2001;
Lowry, 2012). Those parents are often counselled away from exposing their children to two
languages by clinicians (Kohnert et al. 2005; Paradis 2007; Thordardottir 2002) and it is
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suggested to them to use only one language at home, preferably the dominant language of the
community in which they live, in order to simplify language input (Kremer-Sadlik, 2005; Yu,
2013). Clinicians usually support their advice by suggesting that bilingual exposure would
“confuse” the child, due to an exposure overload (Hambly & Fombonne, 2012), which, as a
consequence, would lead to additional delays in language development (Ohashi et al., 2012).
As reported by Thordardottir (2002), the advice of limiting language use to only one language
is frequently given to the ‘bilingual’ parents of children with Down’s syndrome. Nevertheless,
many of those parents choose to go against such advice and continue to bring up their children
bilingually, as they feel that their children are benefitting from it. Similar findings were reported
by Kohnert et al. (2005) and Paradis (2007) who investigated the issue of bilingual up-bringing of
children with SLI. Parents of children with SLI were also counselled against exposing children to
a second language. Even some parents of TD children encounter such opinions (de Houwer,
1999; Fierro-Cobas & Chan, 2001).
2.3.1.
Bilingualism in Children with Down’s syndrome
There is little research evidence to support or refute the suggestions that bilingualism
“meddles” with linguistic and cognitive development of children with developmental disorders
such as DS or SLI. Down’s syndrome is a neurodevelopmental genetic disorder caused by the
trisomy of chromosome 21 (Grant et al., 2010). In DS, children acquiring language have much
more trouble with expressive language, particularly with phonology and syntax, than with
receptive language (Martin et al., 2009). Studies of Down syndrome populations (Kay-Raining
Bird et al., 2005; Feltmate & Kay-Raining Bird, 2008) investigated the course of language
development of simultaneous bilingual children (n=8; M=7;1). Children were divided into two
groups according to their language proficiency: English-dominant bilinguals and balanced
bilinguals2. Control groups consisted of age-matched monolinguals with DS (n=14; M= 6;2) , and
mental age-matched TD monolinguals (n=18; M=2;6) and bilinguals (n=11; M=2;9). After
groups were matched according to their age and non-verbal cognition, their performance was
assessed on standardized and non-standardized language measures, in both languages for the
bilingual children. The analyses of the collected language samples revealed that bilinguallyexposed children with Down’s syndrome show development in both of their languages, but more
importantly, bilingual groups with Down’s syndrome demonstrated the usual profile of
weaknesses relative to mental age matched typically developing bilingual controls. At the same
time, the results of the study show that there were almost no consistent differences between the
2
They show equal strengths (or weaknesses) in both languages.
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mono- and bilingual children with Down’s syndrome on English measures. The authors
concluded that children with this disorder are able to become bilingual.
2.3.2.
Bilingualism in Children with Specific Language Impairment
Specific language impairment (SLI) is a neurodevelopmental disorder caused by genetic
factors. SLI is a disorder with primary language effects. It is characterised by significant delay and
impairments in expressive and receptive language, with prevalent deficits in morphosyntax3, but,
supposedly, no deficits outside of language (Justice, 2006; Paradis, 2010). Studies of bilingual
populations with SLI suggest that children with this disorder, despite clinicians advice, do not
experience any additional delays in language development due to bilingual exposure, and in fact
are able to become successfully bilingual (Paradis et al. 2003, 2011; Kohnert et al., 2005). For
instance, a study by Paradis et al. (2003) investigated the morphosyntactic abilities of
simultaneous French-English (n=8; M=6;11) bilinguals with SLI. The control groups consisted
of French (n=10; M= not specified) and English monolingual children (n=21; M= not specified)
with the same language disorder. Research evidence provided by the analyses of language
measures revealed that both monolingual and bilingual children with SLI had trouble with tensebearing morphemes (walk-ed). More importantly, the authors of the study reported that there was
no difference between the groups in terms of types and severity of errors, in either language. The
similarities between the language profiles of monolingual and bilingual children suggest that
exposure to two languages is not a liability for children with SLI.
Even though the presented studies provide some observations about the language
development in children with DS and SLI, their findings dot provide sufficient and satisfactory
evidence. Hambly and Fombonne (2012) correctly point out that the main limitations of these
studies were the small sample sizes, and the choice of participants: samples included
predominantly individuals with intensive bilingual exposure4, who possessed productive
expressive bilingual abilities. That suggests that, while some bilingually-exposed children with DD
are able to acquire language to extents comparable to their monolingual peers, this does not
automatically imply one can expect the same proficiency in all bilingually-exposed children with
DD (Genesee, 2006). Larger samples need to be tested, and children with DD need to be
followed longitudinally in order to understand the tempo and patterns of their language growth.
3
4
For instance, in English SLI, children have particular problems with finite verb morphology (Paradis, 2010).
With two majority languages: Canadians with English and French (Paradis et al., 2003).
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3. Autism Spectrum Disorders
Autism spectrum disorder (ASD) is a neurodevelopmental disorder in the category of pervasive
developmental disorders (PDD) which is characterized by severe and pervasive behavioral and
social communication impairments. Within the category of ASD, researchers and clinicians
include autism, Asperger’s syndrome, and pervasive developmental disorder – not otherwise
specified (Levy et al., 2009). According to the data collected by the ASD and Developmental
Disabilities Monitoring Network, 1 out of 110 children in the United States has an ASD. So, on
average, approximately 1% of the world’s population is affected by this disorder. It is also
generally agreed that ASD occurs equally across populations regardless of race, ethnicity, culture,
or socioeconomic background (Dyches et al., 2004; Jarquin, 2011). This predicts that
approximately 70 million people in the world have a disorder that falls within the spectrum of
ASD.
The Diagnostic and Statistical Manual of Mental Disorders, 4th edition, (APA, 2000) provides
standardized criteria to help diagnose ASD; qualitative impairments in social interaction and
communication, as well as restricted stereotyped and repetitive patterns of behavior, activities and
interests occur persistently in autistic disorder, Asperger’s syndrome and PDD-NOS. In the new
version of DSM – DSM-V these separate labels were replaced by one umbrella term of ASD
(APA, 2013). Further distinctions are made according to disorder’s severity levels. Diagnosing
and assessment of severity of ASD usually involves two standardized measures: ADOS and ADIR. The ADI-R is a structured interview used for diagnosing ASD, planning treatment, and
distinguishing ASD from other developmental disorders (Le Couter et al., 2003). The ADOS is a
measure which allows diagnosing and assessing the level of severity in ASD. The instrument
consists of a series of structured and semi-structured tasks that involve social interaction between
the examiner and the subject (Lord et al., 2003).
Individuals with ASD usually struggle to communicate and interact with other people, and
they have trouble with expressing their needs and feelings. They show a preference for routines
and a compulsive need of keeping and doing things in a specific order. Moreover, they often find
unusual hobbies, overly focus on topics of personal interest (Frith, 1991) and have strong food
likes and dislikes. Even though all people with ASD present some difficulties in the same areas,
their individual profiles vary greatly, i.e. they present heterogeneous behaviors which are
inconsistent across the ASD population (APA, 2000).
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3.1.
Kacper Sulak
Language in Monolinguals with ASD
The study of ASD puts particular stress on language ability, since it has been argued to be a
strong predictor of general functional outcome in this condition (Nordin & Gillberg, 1998).
Language development in ASD is characterized by a severe delay in, or total lack of, spoken
language development. The language use of the verbal people with ASD is marked by
repetitiveness, and it is often stereotyped. The individuals with adequate speech usually struggle
to initiate and sustain conversations with others (DSM-IV; APA, 2000). As argued by Williams
and Minshew (2010), this disorder clearly affects social functioning, but its effect reaches beyond
pragmatics in the development and use of language.
Siegal and Blades (2003) maintain that auditory processing is the key gatekeeper for later
development, since children normally come to encounter language through auditory processing.
They further suggest that impairments in auditory processing could be one of the underlying
factors in ASD, and support their argument with evidence provided by several studies (Plaisted et
al., 2003; Ceponiene et al., 2003). The effects of developmental disorders, and/or impairments
associated with these disorders, occur even prior to the diagnosis of an atypical development
(Geschwind & Levitt, 2007. These effects further influence the functioning of a child’s brain and
its development across the lifespan (Karmiloff-Smith, 2009). Consequently, the brain of a child
with ASD may develop alternative strategies of information processing which could either
interfere with- or facilitate optimal functioning of the brain. Therefore, two major factors play a
role in the way children with autism learn and use language: the inherent brain differences which
occur early in the development might influence language processing, and the response of the
brain to environmental input might influence alternative language processing strategies as a
consequence (Williams & Minshew, 2010; Siegal & Blades, 2003).
Because processing of auditory input in ASD is expected to be different from the typical
auditory processing (Siegal & Blades, 2003), people with ASD struggle to comprehend and attend
to spoken language. Typically-developing infants are able to differentiate speech from nonspeech sounds, and they can discriminate words and sentences within a stream of connected
speech (Bates, 1993; Friederici, 2005); these tasks cause difficulty for young children with ASD.
They do not show a preference for their mothers’ voice and often fail to respond to their own
names (Klin, 1991; Nadig et al., 2007). The speech of children and adults with ASD is often
characterized by the use of echolalia or parroting which is automatic “lexically, prosodic, and
syntactically faithful repetition” of other people’s speech (Walenski et al., 2006: 14). Individuals
with ASD may often repeat questions instead of answering them or repeat “chunks” of language
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such as television commercials, which suggests that these individuals store information
holistically, without analysing and integrating it (Wetherby & Prizant, 2005). During social
interactions, they may speak with an unusual intonation pattern, distinctive prosody, or timing
and rhythm (Diehl & Paul, 2012 & 2013, Paul et al., 2005). In general, their speech is sparse.
Compared to TD or DD age peers, people with ASD use shorter utterances, and their speech is
characterized by reduced syntactic complexity (e.g. Tager-Flusberg et al., 1990). On the other
hand, they may use complex sentences before naming an object, because they have trouble with
learning the conventional meanings of words and developing prototypes, due to difficulties in
determining saliency (Williams & Minshew, 2010). Learning concepts such as labels for emotions
or beliefs causes them particular trouble (Gastgeb et al., 2006). Finally, studies of spontaneous
speech show that children with ASD tend to omit inflectional morphemes, such as suffixes, and
produce bare forms more frequently than their typically developing or developmentally delayed
peers. This pattern was found to be consistent for both regularly inflected forms, such as present
participles, and regular past tenses (Bartolucci et al., 1980). Interestingly, children with ASD were
found to have no serious trouble with irregular forms (Bartolucci et al., 1980).
However, not all individuals with ASD have such severe difficulties with language use and
communication. Approximately 30% to 40% of people with ASD are defined as high-functioning
individuals (Fombonne, 2005). They present with some autistic disorders, but have relatively high
IQ scores and they are able to communicate verbally, even though for some of them verbal
communication is significantly limited. Like most of the people with Asperger’s syndrome which
is also included within ASD, some of them have relatively intact formal language skills and large
productive vocabularies (Reichow et al., 2008), but they tend to use precise syntax, even in
everyday speech, compared to their typically-developing peers whose speech may be more casual
and less precise (Frith and Happé, 1994, Shirberg et al., 2001). Although language disorders do
not always persist in ASD, social interaction and pragmatics are generally considered an area of
weakness in this population as is shown, for instance, by their problems with the comprehension
of figurative language (Norbury, 2004). Furthermore, people with ASD are said to have impaired
theory of mind which is the ability to attribute mental states, such as beliefs, intents or desires, to
oneself and other people, and to recognise the difference between one’s own beliefs, intents and
desires, and those of others’ (Frith & Happé, 1994). From the presented discussion, we may
conclude that language learning poses a great challenge for children with autism spectrum
disorders, due to a different architecture of their brain, and the way they process the input. As a
consequence, deficiencies during language acquisition lead to impairments in the use and
comprehension of language in individuals with ASD.
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3.2.
Kacper Sulak
Autism-Related Factors Which Potentially Limit Bilingual Learning
Some studies of disorders with primary and secondary language effects provide negative
evidence to the suggestions that bilingual exposure leads to additional delays in language
development, e.g. in Down’s syndrome or SLI. In ASD, severe social impairments, related to
attention to voice and joint attention, are persistent, whereas in SLI or Down’s syndrome they
generally do not occur. Therefore, we may expect that children with ASD could experience
additional delays growing up bilingually, since it involves not only dealing with two language
systems, but also with two sets of social interaction. Hambly and Fombonne (2012) convincingly
argue that joint attention and attention to voice are so crucial in the process of language learning
that these autism-related deficits could possibly restrict the abilities of bilingually-exposed
individuals to acquire language. As a result, these deficits could lead to additional language delays
which are not experienced by their peers from monolingual environments. They further specify a
number of autism-related factors which potentially limit language acquisition and bilingual
learning.

Due to deficits in attention to voice, children with ASD process “reduced” auditory
input. Auditory input plays an even more important role in bilingual learning, because a
child needs to recognise the phonological differences between the two acquired
languages.

Moreover, autistic children pay little attention to facial expressions and movements
during speech, which provide important visual cues for sorting languages (Weikum et al.,
2007).

Consequentially, deficits in joint attention are suggested to potentially worsen expressive
and receptive language delays for bilingually-exposed children with ASD.

Furthermore, these deficits could lead to problems with sorting referential cues of
pointing and eye gaze which help mapping labels to the appropriate referent (one or more
labels from each language).
Joint attention was suggested to be at least facilitative in lexical acquisition, irrespective of
whether a child is raised in a monolingual or a multilingual environment (Baldwin, 1993;
Tomasello, 1995). Indeed, joint attention focused on objects was found to facilitate learning
nouns, and focused on actions was suggested to facilitate learning verbs (Tomasello & Kruger,
1992); but, in particular, visual cues such as facial expressions or gestures have been found to
positively influence second language acquisition (Sueyoshi & Hardison, 2005; Hardison, 2003).
Von Raffler-Engel argues that ‘‘eliminating the visual modality creates an unnatural condition
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which strains the auditory receptors to capacity’’ (von Raffler-Engel, 1980: 235). Nonverbal
communication gives clues to what a speaker is thinking about, but cultural differences may
interfere with understanding a message (Pennycook, 1985). For instance, in the Korean culture
facial expressions are different from those in Western cultures in terms of subtlety. An ability to
correctly interpret others’ facial expressions or emotions plays an important role in nonverbal
communication (Yum, 1987). Therefore, a child learning two languages needs to realize that
different sets of social interaction may require attending to specific visual cues and, subsequently,
use of different means of nonverbal communication in a particular setting. Furthermore,
attention to voice could critically affect autistic children’s outcomes. One of the first studies of
the effects of bilingual exposure in ASD showed that high functioning children with ASD
acquired English (which was their L2) with a non-native accent that was closer to their mothers’
accent, rather than the native accent which characterized English of their peers (Baron-Cohen &
Staunton, 1994).
Leaving aside these factors, timing of bilingual exposure is also presumed to critically
influence bilingual acquisition – early exposure, i.e. within the first year of life, is said to have an
essential impact on differentiating and sorting linguistic input, including vowel and consonant
contrasts (Werker et al., 2009). Pons et al. (2009) suggest that toddlers between the sixth and
twelfth month of their lives become fine-tuned to a specific sensory input which characterizes
their environment. Based on these findings, Hambly and Fombonne (2012) hypothesise that
there may be differences in perceptual abilities and word-learning strategies between the
monolingual and the bilingually-exposed children with ASD during the first year of their life.
However, no study has yet investigated this issue; therefore, no evidence is available which would
provide an unequivocal support, or rejection, of this assumption. Nevertheless, it is indispensable
to present the available literature regarding language development in children with ASD who are
raised in bilingual families, since the premise that bilingual exposure is detrimental to the alreadydelayed language development is still popular among clinicians working with autistic children
(Hambly & Fombonne, 2012; Yu, 2013).
3.3.
Language in Bilingually-Exposed Children with ASD
Without doubt, language learning poses a great challenge to many people with ASD. As was
mentioned earlier, approximately 1% of the world population has an ASD. At the same time,
Kremer-Sadlik (2005) reports that about 50% of the world’s population speaks more than one
language, and in many places bilingualism is not only the norm, but also a necessity. It is, then,
plausible to say that there are several million children with ASD who are raised in bilingual or
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multilingual environments. More importantly, Hambly and Fombonne stress that “(…) there is
an urgent need to understand the impact of bilingual exposure on the language development in
(young) children with autism spectrum disorders, since there is a prevalent belief in clinical
settings that bilingually-exposed children with ASD may experience additional delays in language
development” (2012: 1342). The following section presents the studies hitherto-published, which
focus on the language development in children with ASD who are brought up in bilingual and
multilingual environments. Because there are few studies discussing this issue, it is even more
important to review their value, hence the amount of detail. The recent publication of the
discussed studies show that the present problem is still a very fresh research topic and a lot more
needs be investigated and discussed in this particular research area.
3.3.1.
Lexical Skills
There are several reliable predictors of language outcomes in ASD. Petersen et al. (2012)
chose to focus on lexical skills, since they have been argued to provide reliable predictions of
language development (Condouris et al., 2003). In the study, Chinese-English bilinguals were
compared with age-matched English monolinguals, with regard to the outcomes on the lexical
skills tasks. Bilingual participants were selected according to the amounts of language exposure
they received in each language, their proficiency, and other language-specific factors which could
have affected their vocabulary scores. This procedure ensured that the bilingual group was as
homogenous as possible. All bilingual participants were simultaneously-exposed to either the
Cantonese or the Mandarin variety of Chinese, and to English before the age of three(n=14;
M=4;11). Monolingual participants (n=14; M=4;11) were children who were enrolled in a
previous study which investigated the influence of early interventions for children with ASD
(Mirenda et al., 2005). The authors of the study expected that the monolinguals and bilinguals
would have conceptual production vocabularies that were comparable in size, and that bilinguals’
language scores and comprehension vocabularies would not be significantly smaller compared to
those of monolingual peers.
Participants were tested on a number of standardized measures. The Peabody Picture
Vocabulary Test, Third Edition, (PPVT-III; Dunn & Dunn, 1997) and its Chinese equivalent (Lu
& Liu, 1994)5 were used to assess single word receptive vocabulary for each language. To
measure the general level of language comprehension and production, the Preschool Language
Scale (PLS-3) (Zimmerman et al., 1992) was used. PLS-3 is a standardized diagnostic measure
which assesses comprehension and production language skills in infants and young children. The
5
It was used for testing Chinese-English bilinguals.
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Auditory Comprehension score and the Expressive Communication score were calculated for use
in the following study. Furthermore, to estimate the NVIQ of the participants, a combination of
Visual Reception and Fine Motor subscales of the Mullen Scales for Early Learning (MSEL)
(Mullen, 1995) was used. The MSEL is a measure of cognitive functioning for infants and
children from birth through 68 months of age (Mullen 1995). Parents of all participants were
asked to estimate the total number of hours their children spent in therapy; but, most
importantly, they were asked to fill in the English version of the Communicative Development
Inventories (CDIs) (Fenson et al., 1993). CDI is a long checklist tool which allows for measuring
vocabulary size and growth (Fenson et al., 1993). Parents of the bilingual participants were also
asked to complete a Chinese equivalent of the CDI (Tardif et al., 2008).
The measures were used to calculate a number of raw scores for English, and Chinese – for
bilingual children. Raw score was defined as the total number of words checked off by parents as
spoken by their child. Total vocabulary scores were calculated for bilinguals by summing English
and Chinese raw scores; for monolinguals, total vocabulary scores equaled their English raw
score. Total vocabulary scores were then converted into total conceptual vocabulary scores – a
measure which describes all concepts lexicalized in either language by the child.
For the
bilinguals, English and Chinese vocabularies were added together, and translated language
equivalents were counted only once.
Preliminary results of the study found no significant difference between the groups with
regard to the total number of therapy hours (p=0.58) or chronological age (p=0.99), in any
combination. However, a statistically significant difference between the groups was found with
regards to the NVIQ scores (p=0.001). Children from the bilingual group scored significantly
higher (91.36; SD=21.96) on the MSEL (Mullen, 1995) scales compared to the monolingual
controls (59.29; SD=23.62); so NVIQ scores were subsequently used a covariate in the further
analysis. Even though a significant group effect was found for total vocabulary scores, no such
effect was found for the English CDI scores or total conceptual vocabulary scores. After
controlling for the effect of NVIQ, the analysis of the data retrieved from the PLS-3 scales and
PPVT-III revealed no significant differences between the groups on either of the measures.
Ultimately, the same was found when English and Chinese scores of the bilinguals were
compared; descriptive statistics revealed that there was no significant difference between the
English and Chinese total vocabulary scores or English and Chinese PPVT-III scores.
Moreover, authors of the study report that when the effects of NVIQ were controlled-for,
results of the statistical analysis showed that bilingual children had equivalent English- and
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conceptual vocabulary sizes compared to their monolingual age-matched peers, but their total
production vocabularies were larger. This is consistent with findings of the study comparing
lexical skills of monolinguals and bilinguals in typically-developing populations, which has found
that the conceptual vocabulary sizes of typically-developing bilinguals are equal to or larger than
those of typically-developing monolinguals (Pearson et al., 1993). Petersen et al. (2012) conclude
their considerations by arguing that exposure to different languages in different environments,
for instance, to mainstream language at school and during interventions, to heritage language at
home, does not seem to have an impact on language development in children with ASD. They
further propose that children with ASD are apparently likely to become bilingual.
3.3.2.
Early Language Milestones
While Petersen et al. (2012) chose to test their predictions using lexical skills tasks, Hambly
and Fombonne (2012) chose to test their hypothesis by comparing bilingually-exposed children
with monolingual age-matched peers, with regard to achievement of early language milestone.
Similarly to lexical skills, early language milestones have been argued to be strong predictors of
later language development in children with ASD (Smith, Mirenda & Zaidman-Zait, 2007).
The authors of the study entertained a hypothesis which was derived from the suggestions of
many clinicians who deal with ASD, namely, that social interaction deficits in ASD are likely to
cause additional language delays for bilingually-exposed children, who would be, then, less likely
to reach the language level of their monolingual peers. They specified that the delays for
bilingually-exposed populations would manifest themselves in smaller expressive lexicons, lower
levels of language comprehension and production, and later onset of early language milestones.
The study focused, above all, on the timing of achievement of early language milestones in
simultaneous and successive bilinguals who were compared to age matched monolinguals. The
inclusion criteria limited the choice of participants to children whose spoken vocabulary was
English, French, Chinese or another language6 for which expressive vocabulary questionnaires
were available. Simultaneous bilinguals (n=24; 4;10) were defined as children who were exposed
to two languages during the first year of life, and sequential bilinguals (n=21; 4;10) – as children
who received bilingual exposure after the age of 12 months. Monolingual controls had no history
of bilingual exposure (n=30; M=4;6). The age of 12 months was chosen as the age distinguishing
simultaneous bilinguals from successive bilinguals, because around that age changes in toddlers’
speech perception occur (Werker et al., 2009; Pons et al., 2009).The more general hypothesis of
6
Second languages of exposure included Farsi, Hebrew, Italian, Spanish, Romanian and/or Tamil.
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the study predicted that successive bilinguals should present with even greater language delays
than simultaneous bilinguals, because their bilingual exposure started after infancy.
A variety of instruments was used in the study to assess the language development in the
tested groups, define their background and the socio-economic status of their families. Parents
were also asked to fill out week-long language diaries in which they had to specify the
communication partners of their child and estimates of language exposure for each day of the
week. They were also asked to specify any kind of treatment, therapy or intervention their child
received prior to the study. The Autism Diagnostic Interview, Revised (ADI-R) (Le Couteur et
al., 2003), the CDI and its available language adaptations (Fenson et al., 1993), were used to elicit
information about early language milestones, such as age of first words and phrases, overall level
of language, comprehension of simple language, pointing for joint attention initiation and
response. The total expressive vocabulary was used as an indicator of the total conceptual
vocabulary of monolinguals as well as bilinguals. In other words, CDI was used to assess whether
total expressive vocabularies of monolinguals and bilinguals were equal in size. For the latter
group, the two vocabularies were added together, and translated language equivalents were
counted only once. The Social Responsiveness Scale was used to measure the severity of the
disorder within a child’s natural environments (Constantino, 2002); this measure is applicable
only for children aged ≥4; 0. Lastly, Vineland Adaptive Behavior Scales, Second Edition (VABSII) (Sparrow et al., 2005) was chosen to measure expressive and receptive communication of
bilingual participants. Some effects of bilingual exposure could lead to increased social
impairment effects in ASD; therefore, the interpersonal subdomain of VABS-II measure was
capitalized as the variable of interest in the study, due to its focus on social skills and
interpersonal relations.
The results of the descriptive statistics analysis showed a significant difference between the
amounts of lifetime bilingual exposure between the simultaneous and sequential bilinguals. They
also showed that it was not constant across time (p<0.001), but the amount of recent exposure
was similar, when the data from language diaries and language environment interview from the
past 6-12 months were compared. In terms of social impairments, social abilities of participants
were evenly distributed in the sample. Among the three exposure groups, simultaneous bilinguals
scored highest and sequential bilinguals had the lowest scores in the Interpersonal subdomain of
VABS-II, which was found to be the only significant between-group difference (p= 0.038). Other
than that, there were no significant differences between the groups on the other expressive and
receptive measures. In general, simultaneous bilingual and monolingual children scored higher
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than the sequential bilingual children, but there was no significant difference between the groups
for the total conceptual vocabulary counts and dominant-language scores.
The findings of the study gave negative evidence to the assumption that bilingual exposure
may be an additional liability to language development in ASD. Timing of bilingual exposure
(infancy period versus post-infancy period) was found to be a factor which does not seem to
impact the dominant-language abilities of bilingually-exposed children. Even more surprising is
the fact that 62% of bilingually-exposed children were found to successfully acquire bilingual
vocabulary already in early childhood, but their minority language vocabularies were much
smaller than those of their majority languages. Furthermore, even though simultaneous bilinguals
could have some perceptual advantage due to bilingual exposure7, “the benefits of this (early)
exposure may not be fully apparent in early childhood” (Hambly & Fombonne, 2012: 1349). The
authors conclude that language development in children with ASD is unlikely to be further
aggravated due to exposure to two languages. They subsequently relate their findings to the result
of the studies of bilingual populations with Down’s syndrome and SLI. In the following disorders
social interaction impairments generally do not occur. Despite severe deficits in social interaction
abilities, bilingually-exposed children with ASD are able to develop language abilities comparable
to those of autistic monolinguals. In other words, children with ASD are likely to reach similar
language levels, regardless whether their linguistic environment is monolingual or bilingual, even
though there are theoretical reasons why they may react to bilingual language learning differently,
due to social interaction impairments.
Based on those findings, Ohashi et al. (2012) tested an even younger group of recentlydiagnosed, bilingually-exposed children with age-matched monolinguals, with regards to the onset
of early language milestones. The authors of this study contended that a bilingual environment
would not disadvantage language development in young children with ASD, even in the early
stages. They further argued that, in the previous studies (Hambly & Fombonne, 2012; Petersen et
al., 2012), some children received considerable amounts of corrective Autism-related and
language interventions which could have significantly influenced their development. Thus, very
young children with ASD, who received very little or no intervention, were selected as
participants in their study. Furthermore, they stressed that little has been said about the impact of
very early bilingual exposure in the absence of substantial intervention. Therefore, the total
number of intervention hours was used as a covariate in the statistical analysis of the collected
data.
7
Because simultaneous bilinguals had higher scores on the Interpersonal subdomain of VABS-II (p= 0.038).
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The participants were children with a diagnosis of ASD confirmed by ADOS (Lord et al.,
2003) and/or ADI-R (Le Couteur et al., 2003) and a clinician using DSM-IV (APA, 2000) criteria.
The ADI-R is a structured interview used for diagnosing ASD, planning treatment, and
distinguishing ASD from other developmental disorders (Le Couter et al., 2003).
The study compared early French-English bilinguals (BE) (n=20; M= 3;5) with early French
and English monolinguals (ME) (n=40; M=3;5) . The BE group consisted solely of simultaneous
bilinguals who had either English or French as their dominant language. The groups were
matched according to the NVIQ and chronological age at the time of the assessment.
Furthermore, children were compared with regard to the severity of autistic communication
impairments and occurrence of the following early language milestones: age of first words and
phrases; receptive and expressive vocabulary scores, and functional communication scores.
Research data were collected from a number of standardized measures. ADI-R (Le Couteur
et al., 2003) was used to collect information about the groups’ early milestones, first words and
phrases, for subsequent comparison. ADOS Communication total scores (Lord et al., 2003) were
used to determine and compare the severity of Autism-related communication impairments in
the monolingual and bilingual groups. Raw scores from the auditory- and expressive
comprehension subscales of PLS-4 (Zimmerman et al., 2002) were used to compare monolingual
and bilingual groups with regard to receptive and expressive language. VABS-II Communication
scores (Sparrow et al., 2005) were used to compare the groups with regard to functional
communication skills. Furthermore, service logs filled in by parents were used to estimate the
total number of hours of intervention received by a child.
Analysis of the statistics showed that monolingual and bilingual groups were well-matched
with regard to NVIQ (p=0.48) and chronological age (p=0.94). No statistically significant
difference was found between two tested groups when the scores from ADI-R and ADOS were
compared by group (p= 0.59), particularly with regard to early language milestones, but also with
regard to the number of hours of received intervention (Ohashi et al., 2012). Moreover, no
statistically significant difference between the groups was found on any other measures
capitalized in the study, which was consistent with the findings of the previous studies (Hambly
& Fombonne, 2012; Petersen et al., 2012).
Authors conclude that research evidence provided by the data supports the suggestions that
early bilingual exposure does not lead to additional delays in language development in children
with ASD (Ohashi et al., 2012). They further argue that, similarly to typically-developing bilingual
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and monolingual children who achieve early language milestones around the same age,
bilingually-exposed children with ASD, who received little or no substantial therapy, achieve the
same milestones around the same age as their monolingual peers with ASD, at least in case of
first words and phrases.
3.3.3.
Language Characteristics in Toddlers
The previously presented studies discussed language development in verbal children with
ASD. A recent study by Valicenti et al. (2012) focused on language development in bilinguallyexposed toddlers with ASD in the preverbal stages. Authors correctly pointed out that, until
recently, very little has been said about language abilities of bilingual infants with ASD. Their
study was a review of multidisciplinary assessments which aimed to determine whether there
were any differences between expressive and receptive language profiles of bilingually-exposed
English-Spanish toddlers (n= 40; M = 2;1) and age-matched monolingual English toddlers
(n=40; M = 2;3). Spanish monolingual children were not included in the study, because of the
small sample size.
Qualitative information on language skills of the toddlers was based on parental reports and
clinical observations. Presence of word combinations, cooing, babbling, vocalizations and
number of words reported or observed were all included in the assessment of expressive
language. Responses to ‘no’ or own name, following commands with or without gestures were
included in the analysis of receptive language skills. Assessment of communication means
involved records or observations of pretend play, gestures, pointing, eye contact and facial
expressions. Moreover, the children were assessed with some standardized tests, which included
the Rossetti Infant-Toddler Scale (Rosetti, 1990) – an assessment tool which measures the
preverbal and verbal aspects communication development in infants and toddlers; VABS-II
(Sparrow et al., 2005) was used to examine adaptive behaviors. The Bayley Scales of Infant
Development – Mental Developmental Index, 2nd-3rd Ed. (Bayley, 1993 & 2006) assessed the
developmental level of the toddlers, and Childhood ASD Rating Scale (Schopler et al., 1986) was
used to characterize their autistic features.
The results of the study revealed that bilinguals scored significantly higher (p=0.009) on the
adaptive behaviors composite of VABS-II, but, other than that, no differences between bilinguals
and monolinguals were found with regard to autistic characteristics. Bilingual toddlers cooed
significantly more often than monolinguals (p=0.02), but no other differences were found with
regard to expressive, as well as receptive, language profiles. With regard to their means of
communication, more bilingual toddlers used protoimperative gestures, such as leading to desired
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objects (0.02) or pointing (p=0.02), which is consistent with the findings from studies of bilingual
toddlers in typically-developing populations (Pika et al., 2006; Nicoladis et al., 1999). What is even
more interesting, bilingually-exposed toddlers scored higher on the VABS-II Adaptive Behavior
Composite, just like simultaneous bilinguals, in the study by Hambly and Fombonne (2012).
Since, monolinguals and bilinguals in this study presented comparable cognitive levels, core
features of language, and autistic severity, Valicenti et al. (2012) conclude their study with the
same conclusion as the authors of the previously discussed studies (Hambly & Fombonne, 2012;
Petersen et al., 2012; Ohashi et al; 2012), namely, that bilingualism does not seem to confer an
extra vulnerability in bilingually-exposed toddlers with ASD.
3.3.4.
Language and Literacy
The studies of ASD, discussed up to this point, used various standardized measures. On the
other hand, research by Kay-Raining Bird et al. (2012) was based on a worldwide on-line survey8
which included parental reports discussing reasons for and concerns about bringing up children
with ASD in a bilingual or a multilingual environment. While the following study was much more
of an analysis of a qualitative nature, since it focused on bilingual parents’ attitudes, beliefs and
concerns with regard to bilingual up-bringing of their autistic children; some quantitative data
regarding language and literacy outcomes of these children were provided.
Research data were collected from 49 surveys filled out by parents of children with ASD.
Children were primarily diagnosed with various primary diagnoses including Asperger’s
syndrome, PDD-NOS, autistic disorder, but two with secondary diagnoses of ASD in the
presence of other disorders. Sadly, the level of severity was not assessed or reported in this study.
The majority of respondents were from Canada, so the languages of exposure were most
frequently English and French, even though twelve different languages were identified by the
parents Twelve (25%) of the respondents reported that their children were exposed to only one
language (monolingual exposure), thirty (61%) respondents stated that their children were
exposed to two languages (bilingual exposure), and another seven (14%) reported exposure to
three languages (trilingual exposure), so, tallied together, 75% of these children were raised to be
bilingual or multilingual. “Seventeen children were reported to use sign language (…) or another
augmentative and alternative communication system although only five of these did so as their
primary mode of communication” (Kay-Raining Bird et al., 2012: 54) which implies their low
level of oral performance, and high severity of their disorder. Unfortunately, this issue was not
developed in the following study. The age of children with ASD ranged from 2;11 to 22;00. The
8
Five surveys were actually provided in a paper.
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parents were requested to describe their opinions, beliefs and concerns about the role of
bilingualism in social functioning of their children, and its effects on their development. More
importantly, parents were asked to rate their children’s language skills (understanding and
speaking) and literacy skills (reading and writing) in each language.
Descriptive statistics of the data retrieved from the parental ratings revealed no significant
difference between monolingual children and those, who were exposed to more than one
language, on any of the language or literacy ratings considering first reported9. There were also no
differences between the groups with regard to levels of the disorder’s severity. Some parents
reported that despite exposure to two or more languages their children acquired only one. More
interestingly, many of the parents (75%) reported that they children were acquiring their second
or third languages of exposure, albeit to varying degrees. The analysis of measurable data
provides evidence in support of the assumption that bilingualism has no further bearing on
language development in ASD. Research evidence suggests that children, who have been raised in
bilingual or multilingual environments and were in fact exposed to more than one language, may
be able to reach some levels of proficiency in their second or even third language. That does not
necessarily have to be demanding objective to achieve, if we agree that being bilingual implies
being able to “produce complete meaningful utterances in another language” (Haugen, 1953: 7).
More importantly, it should be kept in mind that parents are not researchers, so they may not be
able to critically and objectively assess their children’s language or literacy skills. In other words,
parents may present with a bias towards overrating their children’s outcomes. Therefore, such
cursory observations should be noted, but the researchers should probe deeper into second and
third language proficiency of people with ASDs living in multilingual environments, in order to
provide more conclusive evidence.
3.4.
Findings and Limitations
The literature review presented in the previous section aimed to discuss all the studies
hitherto-prevailing, considering the effects of bilingual exposure on language development in
children with autism spectrum disorders. Two issues appear in the discussed studies. In the first
place, all the studies provide unanimous evidence in support of the assumption that bilingual
exposure has no further bearing on language development in ASD. In other words, no significant
difference, between the language outcomes of monolinguals and bilingually-exposed (or bilingual)
autistic children, has been found. Moreover, all authors stress that the dearth of research does not
allow for unequivocal support to the above assumption. Indeed, to date, published studies,
9
That is, the dominant language.
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providing statistical findings, can be counted on the fingers of one hand. What can be concluded
so far is that some bilingually-exposed autistic children may acquire language to the levels
comparable with those of their monolingual autistic peers. It may also be contended that some
autistic children are able to become bilingual or even multilingual, though to various extent.
However, based on the stringent research evidence, it is not yet possible to generalize and
conclude that all bilingually-exposed children with ASD can reach the same language levels as
their monolingual peers with ASD (Genesee, 2006), and, what is more, it is not possible to
contend that all children with ASD have sufficient capacities to become bilingual.
Even though the studies discussed offer some promising research evidence, their designs
are not flawless; therefore, it is advisable to consider limitations and to offer some suggestions for
future research. The main problems of all these studies were small sample sizes – it is possible
that larger sample sizes would be able to detect smaller between-group and within-group
differences. Furthermore, the scope of these studies was narrow and focused predominantly on
lexical acquisition and early language development. Becoming a proficient language user implies
learning across all language domains. Therefore all of the language domains need to be taken into
consideration when assessing language outcomes of bilingually-exposed children.
Deficits in morphosyntax and pragmatics should be given particular attention, since they
are said to commonly occur in ASD (Bartolucci et al., 1980; Norbury, 2004). For instance, in
specific language impairment, where deficits in morphosyntax are prevalent, bilingual children
have been found to perform comparably to their monolingual peers on the tasks requiring the
use of accurate tense morphemes (Paradis et al., 2003). The English monolinguals and the
English-French bilinguals were age-matched and tested using the extended optional infinitive
framework (Rice et al., 1995). Paradis et al. (2003) examined their use of non-tense-bearing (go)
and tense-bearing morphemes (goes) in obligatory contexts (e.g. 1st person singular versus 3rd
person singular). The results of the study revealed that the monolinguals and bilinguals with SLI
showed greater accuracy with non-tense than with tense-bearing morphemes. The comparable
accuracy scores for tense-bearing morphemes indicate that the bilingual children do not seem to
exhibit additional deficits in the use of grammatical morphemes when compared to their
monolingual peers. These similarities suggest that bilingual exposure may not have additional
impeding effects on the acquisition of grammatical morphology in SLI (Paradis et al., 2003). With
respect to these findings, it would be wise to screen the autistic bilinguals and monolinguals in
the domain of morphosyntax using EOI framework or Agreement/Tense Omission Model
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(Schütze & Wexler, 1996) to determine whether such error-profile similarities maintain within the
population with autism spectrum disorders.
Furthermore, the report by Kay-Raining Bird et al. (2012) provides some cursory
observations about second language development in autistic children who live in multilingual
environments. These observations should definitely ignite researchers’ attention, since not study
has yet discussed the second language development in the autistic population. It would be also
advisable to test, if there are any language interference effects or language transfers in
typologically similar and typologically different languages of exposure. Finally, these crosssectional studies provide data which define only one stage in development, so “it would be
beneficial to follow bilingually-exposed children longitudinally in order to understand the pace
and patterns of language growth” (Hambly & Fombonne, 2012: 1349).
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4. Executive Control
The previous chapters focused on the linguistic aspects of bilingualism. Leaving aside the
linguistic aspects, bilingualism is still a very complex phenomenon which has been found to have
some surprising effects on cognitive and neural development. With regard to cognitive abilities,
research into bilingualism has recently addressed the issue of increased executive control in
typically-developing populations. At the same time, in ASD, cognitive disability and executive
dysfunction are persistent (Ozonoff et al., 1991). Before these findings are discusssed, it is
essential to clearly define the concept of executive control, otherwise known as executive
functioning or executive functions (EF).
Executive functioning is an umbrella term for a group of cognitive processes that regulate,
control, and manage other cognitive abilities which play an essential role in day-to-day social
functioning (Elliott, 2003; Lewis & Carpendale, 2009). Brown has poetically compared EF to a
conductor of a symphony orchestra: “Regardless of how well the musicians in a symphony
orchestra may play their instruments, they are not likely to produce very good symphonic music if
they do not have a conductor to select what piece is to be played, to start their playing together,
to keep them on time, to modulate the pace and volume of each section, and to introduce or fade
out various instruments at appropriate times (…)” (Brown, 2006: 36). In the following
description, musical instruments metaphorically represent various processes, such as:

Planning,

Working memory,

Attention,

Problem solving,

Verbal reasoning,

Inhibition,

Mental flexibility,

And task switching.
These musical instrument players (cognitive processes) are controlled by the said conductor –
executive functioning (Monsell, 2003). Executive functioning abilities mature at different rates
over time – while some peak in late childhood or adolescence, other abilities progress into early
adulthood. Maturation of these abilities occurs sometimes in spurts, but usually as a sequence, as
they underscore the different directions along which each of their components may develop
(Anderson, 2002; De Luca et al, 2008). While executive functions play a crucial role in social
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functioning and interaction (Elliott, 2003), they have also been suggested to develop through the
said social interaction (Lewis & Carpendale, 2009). Bilinguals, through exposure to two
languages, are simultaneously exposed to two sets of social interaction. It is, then, no surprise that
the studies investigating cognitive abilities found that bilinguals have an advantage on the EF
tasks, compared to monolingual controls.
4.1.
Executive Control in Typically-Developing Bilinguals
Whereas bilingualism had previously been accused of delaying language growth in normal
populations (MacNamara, 1967), more recent research finding show that, contrary to this
assumption, people benefit from a wide range of advantages that bilingual exposure brings.
Cognitive abilities and executive control abilities in particular, have been suggested to be
increased in bilinguals. This, however, raises the “chicken and egg” question; namely, whether
being bilingual enhances executive control, or whether greater cognitive capacity increases the
ability of learning more than one language. Hakuta and Diaz (1985) addressed this issue by
testing a group of bilingual children on Raven’s Matrices (Raven, 1981) which assess general
reasoning and meaning-making abilities. The result of their study showed that scores on the test
were highly-correlated with levels of bilingual proficiency and that bilingualism was in fact a
reliable predictor of children’s performance, and thus their cognitive abilities.
Since the degree to which someone is proficient predicts their cognitive abilities, it is, then,
right to expect that simultaneous bilinguals are most likely to benefit from bilingualism with
regard to increased cognitive abilities, because simultaneous bilingualism involves exposure to
two language systems from very early age, and thus, early cognitive “training”. For instance, Kapa
(2010) tested groups of age-matched simultaneous (n=21; M= 8;5) and successive SpanishEnglish bilinguals (n=36; M=8;11) against English monolingual controls (n=23; M= 8;10). All
children were tested on the Attentional Network Test (ANT) (Fan et al., 2002) which is used to
assess attention and inhibition skills10, Wisconsin Card Sorting Test (WCST) which measures the
mental flexibility abilities (Monchi et al., 2001). While simultaneous bilinguals outperformed
monolinguals children in monitoring, successive bilinguals’ performance was statistically
indistinguishable from both the performance of simultaneous bilinguals and monolinguals. Kapa
(2010) suggests that results of her study provide preliminary evidence to the assumption that age
of second language acquisition may affect the advantage of bilinguals over monolinguals on the
EF tasks (cf. Poarch & van Hell, 2012).
It puts a particular stress on the population with the Attention Deficit Hyperactivity Disorder, in which attention
and inhibition impairments are persistent (Fan et al., 2002).
10
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The reason why bilinguals’ executive control is greater than that of monolinguals may be the
fact that, in bilinguals, language input was found to activate both languages. Therefore bilinguals
need to constantly inhibit the competing two languages, in order to “pick” and use the language
that is relevant to the linguistic context (Bialystok & Martin, 2004; Kroll et al., 2008). Since
bilinguals have different sets of representations in each language for the same concepts, they need
to be constantly aware of which language they have to use in a specific context. The codeswitching ability in bilinguals was found to be directly linked to the increased capacities to inhibit
to irrelevant information, but also to attend to the relevant cues (Linck et al., 2012; Soveri et al.,
2011)
While the majority of the studies report that bilingual children present with increased
inhibitory processing capacities and attention-shifting abilities (e.g. Bialystok, 1999; Carlson &
Meltzoff, 2008; Martin-Rhee & Bialystok, 2008; Poulin-Dubois et al., 2010), some studies also
found that bilinguals display greater conflict-solving abilities (Costa et al., 2008; Carlson &
Meltzoff, 2008), increased working memory capacities and cognitive flexibility (Morales et al.,
2012; Bialystok & Viswanathan, 2011). Greater executive control abilities of bilinguals have also
been suggested to be positively correlated with performance on the tasks requiring learning of
novel word forms (Bartolotti et al., 2011).
Moreover, increased inhibitory processing was found to positively affect bilingual children’s
performance on the false-belief tasks testing theory of mind abilities (Kovacs, 2009; Goetz, 2003;
Rubio-Fernandez & Glucksberg, 2012). For instance, Kovacs (2009) suggested that even threeyear old bilingual Romanian-Hungarian children (n=32; M=3;3) were able to outperform their
monolingual Romanian age-matched (n=32; M=3;3) peers on simple theory of mind tasks. The
aim of the study was to explain which of the accounts: experience-based competence changes or
experience-based performance changes effect in better scores on the above tasks. On the one
hand, experience-based competence approach proposes that bilinguals’ extensive experience with
two languages from birth trains them to develop theory of mind. On the other hand, experiencebased performance changes account proposes that bilinguals would have general advantage in
inhibitory processing due to which would make them perform better on the ToM tasks. If the
first account was to be true, bilingual children would have advantage on the ToM task, as well as
on the control test. However, Kovac (2009) predicted that the increased inhibitory capacities
would make them outperform monolinguals on the theory of mind tasks, but they would not
exhibit such strength on the control task which would not require such abilities. Both groups
were assessed on two ToM tasks, and a control task.
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The first standard short false-belief story tested the general theory of mind skills, and the
second modified ToM task was supposed to mimic a language-switch situation. The control of
general information processing differences was tested by the gizmo task (Zaitchik, 1990). The
descriptive statistics revealed that bilinguals performed significantly better on both false-belief
tests, but, at the same time, had scored comparable to monolingual controls on the control gizmo
test. This gave positive evidence to the experience-based performance changes account. Kovacs
concludes her study with a conjecture that “selecting and monitoring two languages – possibly
beginning already in the crib– may result in improved inhibitory processing, which thus may give
them an advantage in all theory of mind tasks that involve inhibitory control” (Kovacs, 2009: 52).
With regard to the discussed study, this would be an interesting issue to investigate in bilingual
population with ASD, since, on one hand, autistic people are said to have spared inhibitory
control abilities (Robinson et al., 2009; Hill, 2004), but, on the other hand, their theory of mind is
impaired which makes their social functioning particularly difficult (Frith & Happé, 1994).
4.2.
Executive Dysfunctions
In contrast to typically-developing bilinguals, (monolingual) people with autism spectrum
disorders, compared to people from the typical populations, perform significantly worse on the
EF tasks (Ozonoff et al.; 1991, Kalbfleisch & Loughan, 2012; Robinson et al., 2009). These
executive functioning deficits, also known as executive dysfunctions, are defined as disruption to
the efficacy of executive control (Elliott, 2003). There are various causes of this condition, since a
number of neurocognitive processes is involved in the executive system, and each of them may
be compromised be a wide range of environmental factors, or disorders (Nigg, 2006). In ASD,
executive dysfunctions are inherent, since the autistic brain develops differently than a normal
one which leads to establishing atypical processing cues (Williams & Minshew, 2010). In ASD,
executive dysfunction involves impairment in many cognitive abilities, albeit not across the
board. Executive functioning was suggested to play an important role in the social and cognitive
deficits in ASD (de Bruin et al., 2006)
As previously stated, executive functions control a wide range of cognitive processes,
including planning, working memory, attention, problem solving, , inhibition – a capacity to
block inappropriate responses, mental flexibility, verbal fluency, and task switching (Monsell,
2003). In ASD, a distinct profile of the EF impairments includes deficits in fluency and planning.
People with ASD have been found to demonstrate particular impairment on the tasks requiring
planning, which involves developing, monitoring, re-evaluating, and updating a sequence of
planned actions (Hill, 2004). Moreover, with regard to fluency, children with ASD produce less
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complex responses and generate fewer novel words than typically-developing age peers (Gilotty
et al., 2002). While poor mental flexibility was previously suggested to be impaired in autistic
people, as they demonstrate deficits in regulation and modulation of motor acts, and
perseverative, stereotyped behaviors (Hill, 2004; Lopez et al., 2005). Geurts et al. (2009) suggest
that results of these and many other studies are not consistent, and, subsequently these deficits
do not necessarily result from deficits in cognitive flexibility which is consistent with the finding
of the study by Robinson et al. (2009). Interestingly, response inhibition has been recently found
to be spared in autistic people (Robinson et al., 2009; Hill, 2004). This suggestion is rather farfetched, since their performance on the false-belief tasks11, requiring inhibition of inappropriate
responses, is apparently low (Frith & Happé, 1994; Happé, 1995). They were also found to
demonstrate impaired performance on other tasks which require mentalizing12 such as use of belief
and idea words (Ward, 2006). However, people with ASD were found to perform relatively well
on tasks which do not require this ability, such as recognition of basic facial emotion expressions
or sequencing behavioral pictures, they were also Pellicano (2012) maintains that even though it
has been generally agreed that executive dysfunctions are not likely to play a primary causal role
in ASD, it is still likely that the degree of the difficulties in that area may play an important role in
the developmental outcomes of children with ASD, such as adaptive behaviors, social
competence, and educational success.
Deficits in executive control are not specific to ASD, since they have been found in other
developmental disorders, such as attention-deficit/hyperactivity disorder (ADHD) (Marchetta et
al., 2008; Barkley, 1997; Hermodson-Olsen, 2012) and SLI (Henry et al., 2012; Spanoudis &
Natsopoulos, 2011; Windsor & Kohnert 2009; Schwartz, 2009). In, ASD children have particular
trouble with the tasks requiring planning (Hill, 2004; Lopez et al., 2005) or fluency (Gilotty et al.
2002), but their inhibition abilities seem to be spared (Robinson et al., 2009, Hill, 2004). Children
with ADHD have problems with discipline, setting priorities, and organizing. The results of the
studies testing children with ADHD showed that they perform poorly on tasks requiring mental
flexibility, interference control, and semantic fluency (Marchetta et al., 2008; Barkley, 1997).
Moreover, children with SLI, which is primarily a language disorder, have been found to have
impaired processing capacities with regards to EF abilities (Im-Bolter et al., 2006). Studies of this
population showed that children with SLI perform much poorer than the controls on the tasks
assessing verbal and non-verbal executive-loaded working memory, verbal and non-verbal
The tasks which test theory of mind abilities (Happé, 1995).
It is the ability to understand the mental state of oneself and others which underlies overt behavior (Happé, 1995;
Fonagy et al., 2002).
11
12
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fluency, nonverbal inhibition and nonverbal planning, which suggest that children with SLI have
a broader set of cognitive difficulties than that been commonly assumed (Henry et al., 2012;
Spanoudis & Natsopoulos, 2011; Montgomery, 2003). Even though the studies discussed show
that people with ASD, people with SLI, and with ADHD present with different profiles of EF
deficits, it is clear that executive control impairments are generally associated with a range of
developmental disorders. More importantly, some recent studies of bilingual populations with
SLI (Engel de Abreu et al., 2013) and ADHD (Hermodson-Olsen, 2012) suggest that exposure to
one language may have compensating effects on the said deficits.
4.3.
Possible Effects of Bilingual Exposure on the EF Skills in Children with
ASD
Beyond doubt, there is a clear-cut difference between typically-developing bilinguals and
autistic (monolingual) children with regard to their executive control capacities. While the first
group benefits from bilingual exposure and exhibits increased executive control, the second
group demonstrates serious deficits in EF abilities. One obvious question, which could be
derived from these findings, is what could be the effects of bilingual exposure on the EF abilities
of children with Autism spectrum disorder. Considering some recent findings of the studies of
bilingual populations with ADHD and SLI, it is tempting to hypothesize that to some individuals
with ASD, namely, high-functioning individuals or people with Asperger’s syndrome,
simultaneous-bilingual exposure may have a mitigating effect on the previously discussed
processing deficits. Similar assumptions have already been expressed by Paradis (2010) when she
discussed bilingual SLI. She suggested that the superior executive functions emerging from
exposure to two languages may compensate to a certain extent for some of the EF deficits that
come along with SLI.
A recent study by Engel de Abreu et al. (2013) tested a group of bilingual children with SLI
(n=15; M=8;0) against typically-developing monolingual (n=33; M= 8;2) and bilingual controls
(n=33; M=8;1). Participants were tested on a wide range of measures tapping verbal and
visuospatial working memory, selective attention, interference suppression and different domains
of language. The results of the study showed that bilinguals with SLI displayed verbal working
memory limitations, but spared preserved visuospatial executive functioning, which suggests that
this group does not present domain-general deficits in EF. Moreover, a study of bilinguals (n=29;
M= 9;4) with ADHD tested against monolinguals (n=121; M= 10;5) with ADHD suggested that
the former group had fewer problems with EF skills (Hermodson-Olsen, 2012). The author
concludes her study suggesting that, for neurodevelopmentally vulnerable children (ADHD),
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“there may be a protective benefit to bilingual exposure in children otherwise vulnerable to
weakness in executive functioning” (Hermodson-Olsen, 2012: 13). It is important to stress here
that children with ASD are also neurodevelopmentally-affected (Williams & Minshew, 2010),
which could suggest that bilingual exposure may also have a beneficial effect on their EF skills.
Contrary to these “consoling” findings, a study which tested bilinguals with SLI against TD
controls for non-verbal inhibition and shifting abilities, and language proficiency, found a
correlation between language proficiency and EF abilities (Iluz-Cohen & Armon-Lotem, 2013).
While bilinguals with SLI were reported to perform much worse on the EF tasks than the TD
controls, it is rather striking that a monolingual control group with SLI was not included in the
study. It is likely that, although bilinguals with SLI did perform worse than their TD peers on the
EF tasks, they could still outperform their monolingual peers with SLI.
There are very few studies which focus on the performance of bilingual children with
developmental disorders on the EF tasks and their findings are not consistent with each other,
which does not allow for making any general predictions for these populations. Nevertheless, it is
tempting to speculate that, since, as far as we know, bilingually-exposed children with ASD do
not experience additional delays in language development, they could in fact benefit from dual
language learning, since it would act as a cognitive training improving their executive control
skills. Language proficiency was found to be positively correlated with performance on the EF
tasks in the TD populations (Hakuta & Diaz, 1985; Kapa, 2010). Therefore, one would be more
likely to find increased executive control abilities in autistic children who were bilingually-exposed
very early on rather than later. Even though, both simultaneous and successive bilinguals with
ASD should be tested to establish whether timing of exposure and amount of exposure would
influence the test results. Functioning levels and autistic severity should also be considered as
significant factors in future studies. Moreover, it would be advisable to carry out a longitudinal
study, since proficiency in both language changes over time, but also because executive
functioning abilities mature at different rates over time, and some of them occur in spurts, while
others develop gradually (Anderson, 2002; De Luca et al., 2008). Last but not least, bilingual
experience has been found to be positively correlated with performance on the false-belief tasks
(Rubio-Fernandez & Glucksberg, 2012; Kovacs, 2009). Since in ASD false-belief reasoning has
been found to be impaired (Frith & Happé, 1994), it would be important to test bilinguallyexposed autistic children on the theory of mind tasks. Ultimately, it would also be interesting to
follow and observe bilinguals with ASD in their day-to-day social interactions in order to assess
whether (presumably) greater performance on the EF tasks translates into improved social
functioning abilities.
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5. Conclusions
The current review discussed the interdependence and the interplay of the effects of
bilingualism, autistic spectrum disorders, and executive control with a specific focus on the
influence of bilingual exposure on language development in autism. This discussion was
motivated by reports from previous studies that that clinicians and language professionals often
counsel away from exposing children with ASD to more than one language. These professionals
support their advice by stating that, through dual language exposure, a child would be likely to
receive confusing input which would subsequently lead to additional language delays. Moreover,
social interaction impairments have been suggested to potentially negatively influence bilingual
learning in ASD, since bilingualism involves dealing with two language systems, but also implies
dealing with two sets of social interactions. The discussed studies of language characteristics in
bilingual populations with ASD provided modest, yet unanimous evidence which implies that
clinicians’ convictions and advice are unjustified. In other words, to date, no published study has
found that bilingual exposure has bearing on the already delayed language development in ASD.
Moreover, some of the presented studies reported that some children with ASD, who are
exposed to more than one language, are actually acquiring their second or even third languages of
exposure, albeit to different levels. I further argue that even though in the presented studies
bilinguals reach language levels comparable to their monolingual peers, these studies do not
provide enough evidence to make the same predictions for the whole population with autism.
Similarly, the study by Kay-Raining Bird et al. (2012) provides some cursory observations about
second language abilities of bilingually-exposed children with ASD, but many more studies need
to be carried out in order to provide sufficient evidence to support these observations.
Seeing the evidence discussed, bilingual exposure could have a compensating effect on
executive functioning abilities, which have been found to be impaired in people with ASD.
Although studies have provided inconclusive evidence about the effects of bilingualism on
executive control abilities in populations with developmental disorders, future studies that take
into account certain factors and limitations are required. It is crucial to realize that in other
developmental disorders, such as SLI or DS social functioning is typically not as profoundly
affected as in autism. To date, deficits in social interaction have not been found to have any
considerable bearing on language development in bilingually-exposed autistic children. This is a
very important observation, since it provides evidence to conjecture that the capacity of dealing
with two language systems may not be particularly affected by deficits in ASD. With regard to the
societal and social psychological accounts of bilingualism, it may also sound promising to the
“bilingual” families of children with ASD, since consent to use heritage language at home should
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maintain family’s cohesion of discourse, facilitate their communication with their autistic child,
and, subsequently, allow the child to develop heritage language identity (Kremer-Sadlik, 2005; Yu,
2013). Even though my thesis does not provide new research findings, it stresses some problems
which need to receive more attention, but, what is even more important, it exposes the issues
which have not yet been investigated – their study may provide some new interesting insights
about bilinguals with autism spectrum disorders. Future research should involve screening in the
domains of pragmatics and morphosyntax, since deficits within these domains remain
unaddressed in the bilingual population with ASD. When predicting the ultimate language
outcomes of this group, factors such as timing of bilingual exposure and levels of functioning or
severity of disorder should receive particular attention. The typological differences (or
similarities), between two languages that people with ASD are exposed to, may also considerably
influence these outcomes. Therefore, the next step may involve determining, whether certain
combinations of languages, for instance, with different phonological structures and phonemic
repertoires, could be particularly difficult for people with ASD, due to their auditory processing
impairment (Siegal & Blades, 2003).
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