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Therefore, in the last but one chapter of our essay we can mention some interesting cases, possibilities and opportunities to improve the cerebral areas in order that the patient could get the previous knowledge back. Also, it is very interesting to deal with because of the fact that some decades earlier experts thought that cerebral damage and neurons cannot recover Bence, However, in the past few years, scientists discovered that the tact areas could be improved, since the neurons are able to recover from the shock that a brain stroke hemorrhage, embolic, etc had caused.

That might be the reason why dealing with neurobiology in the case of language learning and acquisition seem to be so interesting and important. So dear reader, stay tuned.


Language acquisition is very similar to the process which children use in order to acquire first and second languages. It requires meaningful interactions in the target language in which speakers are concerned not with the form of their utterances but with the messages they are conveying and understanding. It often happens in real life communications and real life situations. Language acquisition is therefore a procedure in which the proper knowledge is acquired independently or - we could say - instinctively.

Even when error correction and explicit teaching of rules are not relevant to language acquisition Brown and Hanlon, , native speakers can modify their utterances in order to clarify what they are about to say or to help listeners understand it. These modifications, therefore, are thought to help the acquisition process, which - as we have already noted - happens spontaneously.

It means that language acquisition is a kind of end product we have to get at the end of the learning procedure. Moreover, when learning a second language, we have got to get to the point that remembering words and phrases do not take place on the ground of previous memorization, but on the ground of an instinct automatic recall.

It means that we have to get to the level when learning the language is not demonstrated and achieved by mugging up words and memorizing things wittingly. In other words, when anyone asks us where we get a word from, the proper answer would be that we do not remember. If it is so, it might be supposed that the words came from unwittingly acquired knowledge, which is actually language acquisition. There are many theories in the field of SLA. They are all trying to prove how the process is going on and how it leads to acquisition finally.

We have opted for his theories, which are, without any doubt, the closes to our theme. According to Krashen, there are five main components of his theory.

Neuroscience of Learning and Second Language Acquisition

Each of the components relates to different aspects of the language learning procedures: This hypothesis actually combines two basic theories of how individuals learn languages. Krashen concludes that there are two systems of language acquisition which are independent, however, absolutely related: The acquired system relates to the unconscious aspect of language acquisition. When people learn their first language by speaking the language naturally in daily interaction with others who speak their native language, this acquired system is at work.

It means that in this system, speakers are less concerned with the structure of their utterances than with the act of communicating meaning. In fact, Krashen privileges the acquired system over the learned system. Moreover, the learned system relates to formal instruction where students engage in formal study to acquire knowledge about the target language.

For example, studying the rules of syntax is part of the learned system Wiley, The monitor hypothesis seeks to show how the acquired system is affected by the learned system. Just when second language learners monitor their speech, they are applying their understanding of learned grammar to form, plan, and initiate their communication. This action can only happen when speakers have abundant time to think about the form and structure of their sentences.

Furthermore, the amount of monitoring occurs on a continuum. It suggests that some language learners over-monitor and some use very little of their learned knowledge and are said to under-monitor. Ideally, speakers point out a balance and monitor at a level where they use their knowledge, which, however, does not succeed always Tucker, This hypothesis assumes that there is a natural order to the way second language learners acquire their target language Krashen, Research suggests that this natural order seems to be characterized by age, the learner's native language, the target language, and the conditions beneath which the second language is being learned.

Normally, the order that the learners follow has four steps:. This hypothesis seeks to explain how second languages are acquired. In its most basic form, the input hypothesis argues that learners progress along the natural order only when they encounter second language input that is one step beyond where they are in the natural order Rivers, Therefore, if a learner is at step one from the above list, they will only proceed along the natural order when they encounter input that is at the second step.

This hypothesis describes external factors that can act as a filter that impedes acquisition. These factors include motivation, self-confidence, and anxiety. For example, if a learner has very low motivation, very low self-confidence, and a high level of anxiety, the affective filter comes into place and inhibits the learner from acquiring the new language Krashen, Students who are motivated, confident, and relaxed about learning the target language have much more success acquiring a second language than those who are trying to learn with the affective filter in place.

According to second language acquisition theory, the role of grammar in language acquisition is useful only when the learner is interested in learning grammar. However, Krashen argues that studying grammar equates to language appreciation and does not positively influence language acquisition. In our practice we have carried out most of the approaches and theories of LA, consequently, we do consider that second language acquisition is the end of an unconscious as well as conscious process by which adequate active language knowledge is obtained.

Even when there are many methods 2 or approaches - we would rather call them enterprises - focusing on early stage learning, we would question the effectiveness of these trials. Therefore, acquisition does never happen without any purposes. There should always be a reason, at least the purpose of the learners to study. In a way, we are to argue Krashen since he separates acquisition and deliberate learning categorically.

We say, however, that learning procedure is important for the final output of production, which is actually leading to acquisition. In addition, we should define production and acquisition. Are these the same or very similar things to each other? We would state that production of the language is of a more complex thing than acquisition, however, production cannot exist without acquisition, therefore the two are built upon each other. Memory is one of the cognitive capacities by which we recall information and reconstruct past experiences, usually bound for present purposes.

Memory is one of the most important ways by which our histories are related to our current actions and experiences. Memory seems to be a source and resource of knowledge Gallloway, We remember experiences and events which are not happening now, therefore memory differs from perception. We remember events which really happened - if there was not a brain damage - so memory is not like mere imagination. Biologically, there is a long procedure taking place in our brain while an event is inscribed into the hemisphere. The internal parts are used to store images and sound and to get memorized and inscribed.

The core of memorizing things is in cortical centers, whereas impulses and inputs are taken from different other parts, temporal lobes and well as the frontal lobe. Remembering is often suffused with emotion, and is closely involved in both extended affective states such as love and grief, and socially significant practices such as promising and commemorating Ramscar,. Getting back information from the storing hemispheres is another way of perceiving things.

Memorizing is also essential to make decisions both individually and collectively. Also, memorization is inevitable for learning languages as well. You have to memorize phrases and structures first in order to be capable of recalling them later. Moreover, it is connected in obscure ways with dreaming. Some memories are shaped by language, others by imagery. In addition, much of moral and social life depends on memory as well Bogen, When talking about memorizing, we have to conduct many other factors.

Memorizing takes place on a higher perceptivity in human brain. Animals can memorize things to, however, they cannot call back audio-lingual events. They can only memorize the pitch or song of the speech and then they carry out the orders we wish them to do. However, animal brain is not capable of reacting properly and is not able to create verbal communication. For instance, dogs can memorize many signs and can react to different situations instinctly. Dogs do not use their cortexes to retain information and recall the memories. Their use their pine glands and reticular formations to react the memorized motions, motifs and the pitch of speech they have heard many times.

Human brain, on the other hand, is capable of thinking cognitively, which means it is not only processes but also analyzes and responds to certain inputs. Moreover, the inputs are recorded in the cortex and become memory. Depending on the way of input audio, visual, senses, touches, etc it is recorded on the exact cerebral cortical area. Audio inputs, for instance, are recorded in the temporal lobe mainly, whereas visual inputs are stored in the occipital regions.

Moreover, in order to fill information with emotions, ideas and reactions, humans use their limbic system in their frontal lobe as well, therefore there is a strict connection between cortical centers all around the brain. The smallest equipment for transmitting information is the neurons, which get the information from the sensatory organs, and then transmit it to the exact brain area.

Neurons are responsible for sensing and transmitting information. When learning a new language, thousands of millions neurons are activated to inscribe the message that is to be transmitted and stored. Throughout this process the information is obtained, transmitted and stored in different areas of our brain. If these certain neurons are block in a way, the obtaining, transmission or storing might be blocked as well. We have carried out an experiment with our students how different blockages affect the learning procedure.

The results and findings will be presented later. In order to understand the results and findings or our study, one has to learn the certain biological processes. As learning is a biological process, it is based on biochemical reactions the create special proteins, so called marker proteins, to modify the electrical currents in the brain in a way that produces correct thoughts or saves information, facts or other sensual impressions we get through the sensory system McDonald, However, not only the brain as a whole is participated.

The neo-cortex does learn quite slowly, whereas the brain stem is about 10 times faster in doing things, but, other than the neo cortex, it can not learn in the formal way we train our neo- cortex. The brain stem learns from exercises. For instance, when we start to learn driving, first of all we try to memorize all the handles we have to use for gas, clutch, gears, blinking and whatever else is required to drive a car properly.

While we are trying to learn this, we use the neo-cortex and it takes us some hours of training to get better. Interestingly enough, learning a second language is a very complex process and still first language acquisition takes place in a very different way. It is because when we first learn our first langue, first we have only audio effects, since we cannot see the written form of the words, structures and texts. We first get the inputs through our hearing which goes into the temporal area lobus temporalis where the data are processed.

When a kid starts learning his or her mother tongue, he first listens to the voice and sound and try to decode them. Decoding takes place in another area, so after the first input the information is transferred to the sensory association area which is situated right above the temporal area, called the parietal area lobus partietalis. In this area all the information concerning the first language is gathered together, including eye movements, intonations, mimic, gestures and visual information as well. Thus, we could say that learning our first languages does not only rely on visual and audio effects which we are supposed to concentrate on when learning a second language , but also on other non-audio and non-visual happenings.

Indefrey , p. In some of these and related studies, the findings of nativelikeness have been interpreted as counter-evidence to critical-period predictions with respect to the attainment of nativelikeness in late L2 acquisition articulated. Recall, however, that proponents of the critical period hypothesis in the L2 context advance the criterion of across-the-board nativelikeness as necessary evidence for rejection of the hypothesis. As stated above, however, the position regarding falsification of the hypothesis by impeccable nativelikeness does not take into account the natural effects of bilingualism, which make it impossible for both early and late bilinguals to be exactly like monolinguals in either the L1 or the L2.

It was also noted that, by the logic of this position, for rejection of the nature-of-bilingualism account and for support of the critical period account one would need evidence of across-the-board monolingual-likeness in the first-learned language of late bilinguals, or in either language of simultaneous bilinguals Birdsong and Vanhove, As seen in the plateau at ceiling, participants with early AoA up to about 7 years of age perform relatively homogeneously and within or close to the range of native controls.

Results of a test of English morphosyntax, as a function of age of arrival in the United States. A Shows overall percent correct for Korean native speakers filled circles and native English controls open circles ; B breaks out test results by grammatical items top and ungrammatical items bottom ; C depicts different functions for ungrammatical rule-based items vs.

Adapted from Flege et al. Republished with permission from Elsevier. Both the top and bottom images reveal increased variability over AoA; however, the degree of variability depends on the grammatical status of the items analyzed, with the cone-shaped scatter of results more pronounced for responses to ungrammatical items than to grammatical items. As a second illustration of sources of variability, Ettlinger et al. In an artificial language based on Shimakonde, a Bantu language of Mozambique, university student participants were trained on noun stems, plurals, diminutives, and diminutive plurals representing animals.

For two types of diminutive plurals in the language, the diminutive and the plural morphemes are simply affixed on the singular stem. A third type of diminutive plurals is more complex, as the vowels in the stem and the plural affix require rephonologization. Some learners termed Simplifiers tended to apply the simple pattern in instances of both complex and simple diminutive plurals; others Learners successfully learned both the complex and simple diminutive plurals; others Non-learners performed poorly overall.

On a prior test of working memory, Learners, Simplifiers and Non-learners performed similarly. However, the groups varied on prior tests of procedural memory and declarative memory. Those participants who were Learners generally scored high on both procedural and declarative memory tests.

Those with high procedural memory scores, but lower declarative memory scores, tended to be Simplifiers. Those with poor procedural memory, irrespective of declarative memory scores, were Non-learners. Adapted from Ettlinger et al. Republished with permission from Cambridge University Press. In some studies, as AoA increases, the outcome of learning of L2 morphosyntax appears to become more variable see, e.

Candidate sources for such wide dispersions can be inferred from an increase over age of the range of values that are associated with relevant experiential variables. For example, in a random participant sample, the range of lengths of residence in the L2 environment, along with the range of years and types of education will increase correspondingly with AoA.

Along with such scaling effects on demographic variables, it is also possible that, with increasing AoA, motivation to attain accuracy in lexico-grammatical knowledge in L2 will become more heterogeneous across participants, particularly so as goals for L2 learning become more diverse. Cognitive aging may also figure in the mix of candidate reasons for age-related variability in L2 attainment. For example, Buczylowska and Petermann summarize age-related differences in six executive function tests administered to participants ranging in age from 18 to 99 years.

Declines in mean scores over age were accompanied by increased age-dependent heterogeneity in scores. Connecting this finding to the cone-shaped dispersion of L2 morphosyntax scores over AoA is not a straightforward matter, however, as the heterogeneity observed by Buczylowska and Petermann is most notable in the later age ranges, whereas most individuals undertaking L2 do not begin so late in life.

Further, the degree of dispersion varied greatly by task in this study. Similarly, Mella et al. Relatedly, Hartshorne and Germine find that the peaks in cognitive skill are not synchronized over skill types, with some occurring earlier than others. A strong case can be made for both general effects and inter-individual effects of progressive cognitive decline, as well as for effects of dopamine declines see above , progressive L1 entrenchment Marchman, ; Elman et al.

At the same time, it is fair to say that further study is needed to establish a direct link between heterogeneity in cognitive function over age and AoA-related patterns of dispersion of results on tests of L2 attainment. It is axiomatic that people vary widely in the effectiveness and efficiency with which they learn an L2.

Often the study of individual differences in L2 learning focuses on exceptionally successful learners. Although researchers do not all agree on terminological distinctions between the notions of ability, aptitude, talent, and giftedness in the context of L2 learning, the cognitive and conative attributes of high achievers in this domain are well understood; for a recent review, including the question of the mutability of aptitude with experience, see Singleton Individuals who attain near-nativelikeness in multiple languages tend to be endowed with high working memory capacity, are highly motivated to learn, and strategically apply metalinguistic knowledge and analysis across their learned languages.

Polyglots — defined by Hyltenstam as those who reach high proficiency in six or more languages after puberty — and hyper- polyglots — for Erard those who proficiently speak, read, or write in at least 11 languages — share the same traits as gifted multilinguals, while also possessing extraordinary verbal memory. They apply their superior analytic skills to recognize patterns in phonology and morphosyntax, and with remarkable executive control are able to switch between languages with little interference. The linguistic savant Christopher Smith et al.

Pring notes that autistic savants also differ behaviorally from non-autistic experts by their obsession with memorization and practice, which appears to be more about the pleasure of obsessiveness than about achievement. According to Pring, it is typical of high achievers, but not of savants, to strategically set goals and to use feedback when learning.

As suggested above, it is more apposite to point out that there are no exceptions to the effects of bilingualism, even among the most talented learners of languages. Turning to less exceptional cases, Della Rosa et al. Their longitudinal study of children living in the South Tyrol region of Italy, where German, Italian, Ladin and English are routinely used, showed specific multilingualism-induced gray matter volume increases in the LIPL.

The researchers suggest that such structural adaptations result from the necessity to apply general memory and attentional functions to the processing of more than one language. A neurogenetic approach to individual differences in L2 learning is advanced by Wong et al. Procedural learning is associated with concatenation of constituents in syntax and with abstract relations between phonology and morphology, and is localized in the prefrontal cortex and basal ganglia.

These differences extend to inhibitory function and executive control, which in L2 processing enable suppression of competing information such as knowledge and intrusion of the L1 Lee, Under the DA account, a mediating role of AoA can be postulated as well, as dopamine receptor and binding declines over age are well documented e.

Taking this approach to variation a step farther, Wong et al. Drawing parallels with personalized medicine in the pharmacological field, the authors suggest that understanding individual differences will lead to customization and optimization of language instruction. For other studies of individual differences in cognitive abilities in particular, differences in procedural, declarative and working memory , and how these play out in second language acquisition, see Morgan-Short et al.

A dual-systems learning model developed by Chandrasekaran et al. The reflective system explicitly develops and tests categorization rules; in contrast, the nature of the reflexive system is procedural and implicit. In experiments involving novel linguistic tone category learning, adult participants initially display a bias toward using the reflective system, which turns out to be ill-adapted to the task. Those individuals who succeed in tone learning are able to shift to the reflexive system, using cortico-striatal connections whose plasticity is regulated by DA reinforcement signals.

Relative to younger participants, older adults appear to be less likely to be able to shift from reflective learning to reflexive learning. Birdsong examines native-language literacy and education as sources of variability across participants in L2 attainment studies. These factors may interact with task type e. Birdsong also notes that both native speakers and L2 learners exhibit grammatical idiosyncrasies and other types of variability in representations of linguistic structure Dabrowska, ; therefore variability per se whatever the type or source is not necessarily evidence of learning deficiencies.

For an overview of individual variation in L2 processing as opposed to attainment , see Van Hell and Abdollahi A feature of bilingualism that conspicuously connects age, plasticity and variability is linguistic dominance. Regarding plasticity and age, it is not always the case that language learned in infancy is the dominant language of a bilingual: Among international adoptees and heritage speakers, dominance shifts involve attrition of the L1, a representational and functional loss which likewise reflects neural plasticity see below.

As concerns variability, inter-individual differences in dominance relationships are natural consequences of idiosyncratic experiences with, skills in, and use of the two languages. No two bilinguals are identical in terms of dominance. Linguistic dominance in bilingualism is understood in terms of dimensions — relative performance in a language skill such as speech rate, picture naming or grammatical accuracy — and in terms of domains — typically, the comparative frequency of use of each language at work, with family members, or at school.

Dominance is not uniquely equatable with relative proficiency as defined in terms of grammatical and lexical accuracy, speech fluency, etc. As with many other features of bilingualism, linguistic dominance is not inherently categorical. Accordingly, in order to faithfully capture the construct, dominance, like AoA, is properly operationalized and analyzed as a continuous subject factor. As with any other continuous variable, participant assignment to dominance categories may mask intra-group variability and result in loss of statistical power e. Some instruments for assessing dominance take into account both domains and dimensions of dominance.

Birdsong reviews methods of calculating dominance indices, along with problems of incommensurability in comparing individual bilinguals who may have the same composite dominance indices, but who vary with respect to the underlying dimensions and domains measured by the instrument. The term is sometimes used or assumed to denote very high or near- nativelike proficiency in both languages.

However, degree of proficiency is independent from degree of dominance. An individual who is at an equally low proficiency level in two languages, and an individual who is highly and equally proficient in two languages, are both by definition balanced bilinguals.

Bilinguals who are not balanced that is, who are dominant in either Language A or Language B are situated to one side or the other of the diagonal. Adapted from Goto Butler and Hakuta Republished with permission from John Wiley and Sons. The direction and degree of dominance in the two languages are dynamic over the lifetime of an individual bilingual. In some cases, and for similar reasons, the L1 may return to dominance, and still further shifts are possible. Grosjean details multiple dominance shifts over 60 years of his life. For a review of research and theory on the relationship between dominance and age, see Birdsong a.

Conceptually as well as in practice, the developmental dynamics of dominance relationships may reflect both L1 loss and L2 gains. For example, among some immigrants and adoptees, there may be little or no ongoing use of the L1; as the L1 withers in terms of domains or dimensions , the L2 perforce becomes the dominant language. On a developmental scenario, a sequential bilingual whose L1 is not fully developed may use and maintain the L1, but as a matter of relative gains in linguistic knowledge and proficiency over time, the L2 eventually outstrips the L1.

Losses in the L1 and gains in the L2, with consequent reflexes in the dominance relationship between the two languages, have been theorized together in terms of maturational constraints on plasticity. After this period the potential for both L1 attrition and L2 attainment declines, with the relevant geometry of both resembling a stretched Pallier advances a different view, whereby the AoA-ultimate L2 attainment function exhibits a linear decline, starting essentially at birth; by contrast, the likelihood and degree of L1 attrition start to drop off only after age For Pallier and Bylund et al.

Thus, with respect to plasticity in dominance relationships in the first decade of life, there are two distinct possibilities. One possibility is that L1 loss, the likelihood of which is highest for several early years, is a greater contributor to dominance shifts than L2 gains, which start to become less likely very early in life, with progressively less influence on shifts from L1 to L2 dominance.

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Another possibility is that L2 gains and L1 losses conspire simultaneously to enable L1-to-L2 shifts of dominance. The latter possibility relates L1 loss and L2 gain under a unified view of plasticity in early childhood development: For a recent empirical study and review of age effects on L1 attrition, see Ahn et al. As L1 loss slows, the point at which a complete shift to L2 dominance can be expected is delayed. Similarly, depth of attrition the degree to which a domain or dimension is diminished and breadth of attrition the number of dimensions and domains diminished should decrease with the age at which the loss begins.

Thus, indirectly through L1 loss, age contributes to variability in L1—L2 dominance relationships see also Montrul, b. Dominance has been shown to be a predictive factor in studies of bilingualism. As an example, Amengual looks at the elicited production of mid vowels among Spanish—Catalan bilinguals in Majorca. However, among the 30 Spanish dominants, those whose BLP scores approached balanced bilingualism i. Adapted from Amengual Republished with permission from Sage Publishing. A study of bilingual speakers in Guatemala by Baird illustrates how the dominance factor accounts for inter-individual variation in bilingualism.

In most varieties of Spanish, the peak of F0 rise occurs after the tonic syllable. In contact and bilingualism contexts, Spanish varieties display an F0 that is closer to sometimes before the tonic syllable. At the same time, for speakers from both communities, the degree of Spanish vs. Adapted from Baird A critical take-away from Baird is that the nature of inter-individual variation is obscured in a simple analysis by binary factors, in this instance place of residence and pre- vs.

More revealing can be examinations of variation along continuous dimensions, in this case distance of peaks from the tonic syllable and degree of Spanish vs. By such an analysis, individual variability along a continuum of peak F0 placement is predicted by degree of dominance, independently of residence.

Researchers have considered the possibility that dominance in the L2 may be associated with monolingual nativelikeness in pronunciation in that language. In a delayed sentence-repetition task for English sentences, Flege et al. A series of follow-up studies by Antoniou and colleagues look more closely at interference effects, in this case with respect to VOT among L2 dominants. For the same bilinguals, Antoniou et al. In contrast to the unilingual mode one language activated results of Antoniou et al. That is, the L1 appears to influence pronunciation in the dominant L2, but not the other way around.

Perception experiments with a larger sample of Greek—English bilinguals Antoniou et al. Results may vary according to production vs. Another illustration of the role of dominance in bilingualism relates to the question of executive control. A considerable body of research e. At the same time, since bilingualism is not a unitary phenomenon and thus not a categorical variable Luk and Bialystok, ; Yow and Li examine degree of dominance as a predictor of cognitive control within bilingual populations.

Among 72 English—Mandarin young adult bilinguals, the researchers find a positive effect for balanced use and balanced proficiency with respect to interference in Stroop task performance and mixing cost in a number-letter mental-set shifting task. In addition, early AoA of the second language is associated with less interference on the Stroop task.


As a related and final example, recent work by Onnis et al. Statistical language learning involves tracking the frequencies of, or the transitional probabilities between, grammatical elements, which results in implicit knowledge of structural regularities. In this study, success in statistical learning of artificial grammars is predicted by the degree to which participants approach or depart from balanced bilingualism, as measured by BLP scores: Thus, degree of bilingual dominance in adulthood is associated with differential ability to learn a novel language.

In this review we have seen how variation in L2 acquisition and bilingualism is conditioned by age, which itself conditions plasticity. We also know that age similarly conditions individual factors such as language experience, L1 attrition and linguistic dominance, which are themselves predictive of variation. Age-related effects of which neurobiological maturation within a critical period is one possible source cannot account for all varieties of non-nativelike outcomes in L2 acquisition, since departures from monolingual-likeness are found not just in post-childhood learning but among from-birth simultaneous bilinguals as well.

The Neurobiological Factors in Second Language Learning and Acquisition

By contrast, bilingualism effects can account for observed non-monolingual-likeness in both the L1 and the L2, whatever the age of learning. At the same time, the degree of L1 activation, L1 entrenchment, L1 attrition and relative L1—L2 dominance — all of which are affected by AoA — modulate attainment levels across L2 learners. The application of different statistical models and methods can result in different shapes of the function that relates AoA to L2 outcomes; such artifacts add another dimension of variability to the picture of L2 acquisition.

We have also considered possible sources of variability in L2 attainment with increasing AoA. These sources range from experiential education, length of residence , to representational L1 entrenchment and to cognitive decline with underlying neurologic causes such as dopamine levels that mediate domain-general learning and processing. The role of cognitive decline in AoA-related variability in L2 learning outcomes is of particular interest for future investigation. This review has brought these concerns into focus with illustrations from two areas of active research, individual differences and bilingual dominance.

With respect to individual differences in L2 learning, we have highlighted the roles of neurogenetic makeup, higher-order cognitive factors, language experience, age-conditioned learning styles and motivation. We have seen that the gradient phenomenon of dominance in bilingualism is dynamic over the lifespan, is conditioned by experience as well as by neural plasticity, and is predictive of phonetic variation, cognitive control, and statistical learning in artificial language paradigms.

In his classic position paper Bley-Vroman , p. From this understanding emerges heuristic guidance for further explorations of the richness of L2 acquisition and bilingualism. The author confirms being the sole contributor of this work and approved it for publication. The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. National Center for Biotechnology Information , U.

Journal List Front Psychol v. Published online Mar Author information Article notes Copyright and License information Disclaimer. This article was submitted to Language Sciences, a section of the journal Frontiers in Psychology. Received Jul 22; Accepted Jan The use, distribution or reproduction in other forums is permitted, provided the original author s and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice.

No use, distribution or reproduction is permitted which does not comply with these terms. This article has been cited by other articles in PMC. Abstract Much of what is known about the outcome of second language acquisition and bilingualism can be summarized in terms of inter-individual variability, plasticity and age. Introduction This review article examines a range of features of second-language L2 acquisition and bilingualism from the intersecting perspectives of plasticity, variability and age.

Notes on Terminology and Concepts In this review, the relationship between age and L2 attainment will be considered with respect to the time at which learning of the L2 begins, be it from birth or at any time thereafter. Plasticity, Variability and Age: Developmental Neurobiology and Behavioral Outcomes The notion of plasticity with respect to adult language acquisition is often traced back to Penfield and Roberts , p.

Open in a separate window. Plasticity, Variability and Critical Periods in L2 Acquisition It is commonly believed that L2 attainment to nativelike levels among adults is impossible because they have passed a critical period for successful learning. Non-nativelike Attainment As a second type of support for critical period effects in L2 acquisition, some researchers point to the lack of evidence for across-the-board nativelikeness in late L2 acquisition e. Nativelikeness It is important to emphasize that, despite bilingualism effects, there are late L2 learners who resemble native monolinguals with respect to targeted aspects of the L2 as opposed to bilinguals being indistinguishable from monolinguals in every measurable respect.

Possible Sources In some studies, as AoA increases, the outcome of learning of L2 morphosyntax appears to become more variable see, e. Individual Differences in L2 Learning It is axiomatic that people vary widely in the effectiveness and efficiency with which they learn an L2. Dominance, Plasticity, Variability and Age A feature of bilingualism that conspicuously connects age, plasticity and variability is linguistic dominance.

Dominance Shifts and Age The direction and degree of dominance in the two languages are dynamic over the lifetime of an individual bilingual. Examples of Prediction and Variation in Dominance Dominance has been shown to be a predictive factor in studies of bilingualism. Conclusion In this review we have seen how variation in L2 acquisition and bilingualism is conditioned by age, which itself conditions plasticity.

Author Contributions The author confirms being the sole contributor of this work and approved it for publication. Conflict of Interest Statement The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Age of onset and nativelikeness in a second language: Neural aspects of second language representation and language control. Age effects in first language attrition: The perception and production of language-specific mid-vowel contrasts: Inter-language interference in VOT production by L2-dominant bilinguals: Two ways to listen: Oxford University Press; , 58— Cascadilla Proceedings Project; , — Lawrence Erlbaum Associates; , — New conceptualizations of linguistic giftedness.

Ultimate attainment in second language acquisition. Decision making in second language acquisition. Psycholinguistic Approaches eds Kroll J. Oxford University Press; , — Age and second language acquisition and processing: John Benjamins; , 99— Three perspectives on non-uniform linguistic attainment. Dominance and age in bilingualism. Cambridge University Press; , 85— In faint praise of folly: On the evidence for maturational constraints in second-language acquisition.

American Psychological Association; , — The logical problem of foreign language learning. Simultaneous bilingualism and perception of a language-specific vowel contrast in the first year of life.