Linguistic ability and early language exposure. Nature, , 38, with permission of the publisher. Two studies longitudinally followed the spoken L1 acquisition of a deaf adolescent and an adult p. After 4 years, he acquired limited vocabulary, could combine single words with gestures, but produced only a single two-word utterance.
Another study followed the spoken English acquisition of a woman whose hearing loss was not identified until she was 31 years old. After 10 years of hearing aid use and spoken English instruction, she was reported to have a vocabulary of approximately 2, words and a grade 2—3 reading level, but her spoken utterances were described as being ungrammatical Curtiss, The slow rate of delayed L1 acquisition observed in this adolescent and adult contrasts sharply with the rate of L1 acquisition in young deaf and hearing children.
By the age of 6 years, hearing children can comprehend as many as 14, words and most grammatical structures of their language Clark, Another study longitudinally observed the L1 acquisition of ASL begun at age 13 by two deaf adolescents who had received no special services in their home countries prior to immigrating with their families to North America Morford, No vocabulary assessment was made, but comprehension tasks given after 7 years of exposure showed both adolescents to suffer from severe comprehension deficits in ASL Morford, Deaf individuals who are not exposed to language in childhood are not completely devoid of communication with those in their surroundings.
Deaf children who acquire little functional, spoken language in early childhood have been observed to gesture for communicative purposes with their families, a phenomenon called home sign in ASL. Detailed analyses of home sign show that deaf children combine points with iconic gestures in a rule-governed fashion to name things in their environment, make comments, and make their needs known to some extent Goldin-Meadow, This line of research shows that the deaf child creates the gesture system and, although they understand it, hearing parents do not appear to use it with the deaf child instead of speech.
Home sign has been documented to occur cross-culturally among deaf children who have otherwise not acquired a spoken or sign language Goldin-Meadow, Home sign was the means of communication used by the two adolescent L1 learners of ASL studied by Morford Although home sign displays many language-like features, it does not appear to function as early L1 acquisition in the critical period phenomenon.
The deaf delayed L1 learners who participated in the experimental and case studies described here did not attain near-native levels of ASL proficiency despite years of using it, even though they had used home sign as young children. Together the results of these diverse studies indicate the effects of critical period for language to be threefold: 1 early L1 acquisition leads to native-like language proficiency in adulthood; 2 early L1 acquisition supports and facilitates subsequent L2 learning, often leading to near native-like L2 proficiency in adulthood; and 3 a lack of early L1 acquisition impairs the ability to learn language throughout life, that is, L1 acquisition that begins uncommonly late in human development leads to limited language proficiency for any language in adulthood.
The critical period phenomenon described here may explain the frequent clinical anecdotes from several countries, including the United States, Canada, Norway, Denmark, and Sweden, that young deaf children who have acquired sign vocabulary are more successful with cochlear implants than those with no sign vocabulary. The first stage of language acquisition is vocabulary learning. This is an area where research is needed due to the substantial rise in the number of deaf children receiving cochlear implants see Chapters 9 and 29 , this volume.
Preliminary research suggests that delayed L1 acquisition has significant neural consequences as well. The degree to which the classic language areas of the anterior left hemisphere are activated during sign language processing are negatively correlated to p. Given that early L1 acquisition facilitates subsequent L2 learning to near-native levels, but late L1 acquisition impedes it, the next question is whether this critical period phenomenon relates to reading development in the deaf population.
Some, but not all, theories of reading development posit that the reader must be able to speak the language represented in the written text in order to comprehend it. In these models, recognizing word meaning occurs only after written letters have been mentally transformed into the speech sounds they represent. Such theories predict that readers who are deaf and do not speak well will have difficulty reading. Early spoken language acquisition supports later sign language acquisition and vice versa, including written representations of spoken language.
This line of research suggests an alternative explanation for low, median literacy levels in the deaf population. If L1 acquisition in early life scaffolds subsequent L2 learning, then it should support L2 reading too, even when the first language is ASL and the second is English. Many deaf individuals have weakly developed language skills in any language, for all the reasons just described. The question is how such weakly developed language skill relate to reading achievement.
Data from Chamberlain, C. ASL syntactic and narrative comprehension in skilled and less skilled adult readers: Bilingual-bimodal evidence for the linguistic basis of reading. Applied Psycholinguistics, 28 , — The two groups of signers were also given standardized reading tests. The results were striking. There was a bimodal distribution of reading achievement between the two groups with no overlap, as Figure Average English reading achievement for the group with strong ASL skill was between the grade 10 to college level, depending upon the particular reading test.
Thus, sign language proficiency is a strong predictor of reading achievement among p. Note that the average reading level of the signers with weak ASL skill was identical to the median reading achievement reported for the deaf school-aged population in the United States, namely between grades 3 and 4 Traxler, This review of research investigating age of acquisition effects on L1 and L2 outcomes allows us to reconsider the question of whether Victor could have become proficient in French Sign Language in the early s had the idea to use it occurred to Itard.
Victor was believed to be about 12 years old when Itard began to teach him French Frith, Toddlers use objects to communicate with their caretakers and then begin to use their hands and arms to point at objects and people before they speak their first words Bates, This means that Victor achieved a prelinguistic level of communication. The research summarized here completes the picture by suggesting that Victor would not have become proficient in French Sign Language because he had grown into adolescence without having acquired any language.
Scholars have suggested that Victor may have been autistic Lane, Socially isolated children, including feral children, often develop autistic-like tendencies, but young autistic children can and do acquire sign and spoken language Frith, If the critical period phenomenon for language described here is robust and a key factor in adult sign language proficiency, why are incomplete language acquisition and low sign language proficiency among deaf signers not more often identified and urgently treated by clinical and educational professionals?
One reason is a lack of educational or clinical models of normal versus delayed sign language acquisition, such as are in place for spoken language acquisition, including assessment tools and specialists. Educators and clinicians need to be trained to assess language development in sign. A clinical anecdote illustrates the serious nature of the problem. An adolescent boy who had been educated in total communication in a public school for deaf students was brought to a university clinic for an educational assessment.
His ability to read English was limited, as was his ability to comprehend simple sentence structure in ASL or signed English. When asked about his sign language skills, his teachers uniformly replied that they could not understand him and attributed this to his quick signing rate.
Language Acquisition Theory | Simply Psychology
His parents, who did not sign, were aware of his limited reading ability but assumed him to be a proficient signer, again due to his fast signing rate. In short, neither his teachers nor his family were aware of his aphasic-like symptoms in sign language. Magnetic resonance imaging MRI scans revealed numerous and widespread brain lesions due to birth complications.
The lesions explained the aphasic-like symptoms in his signing, but they were invisible to professionals unprepared to ascertain the difference between normal and aphasic development in sign language. L2 research with sign and spoken language has found a negative correlation between age of acquisition and L2 attainment. Nonetheless, near-native skills are often achieved by older L2 learners depending upon amount of education undertaken in the second language and the linguistic similarities between the first and second languages.
However, unlike the findings for L2 acquisition, delayed L1 acquisition impedes the ultimate proficiency attained in any language, signed or spoken. Anderson, D. Journal of Deaf Studies and Deaf Education , 7 , 83— Find this resource:. Bates, E. The emergence of symbols: Cognition and communication in infancy. New York: Academic Press. On the inseparability of grammar and the lexicon: Evidence from acquisition, aphasia and real-time processing. Language and Cognitive Processes , 12 , — Birdsong, D. On the evidence for maturational constraints in second language acquisition. Borovsky, A.
Language input and semantic categories: A relation between cognition and early word learning.
Journal of Child Language , 36 , — Chamberlain, C. Applied Psycholinguistics , 28 , — Clark, E. First language acquisition. New York: Cambridge University Press. Corina, D. Sign language processing and the mirror neuron system. Cortex , 42 , — Curtiss, S. Abnormal language acquisition and the modularity of language.
Newmeyer Ed. Dickensen, D. Bringing it all together: The multiple origins, skills, and environmental supports of early literacy. Learning Disabilities Research and Practice , 16 , — Emmorey, K.
Language, cognition and the brain. Effects of age of acquisition on grammatical sensitivity: Evidence from on-line and off-line tasks. Applied Psycholinguistics , 16 , 1— Eubank, L. Critical periods and second language acquisition: Divide et impera. Birdsong Ed. Flege, J. Age constraints on second-language acquisition. Journal of Memory and Language , 41 , 78— Frith, U.
Autism: Explaining the enigma , 2nd edition. Oxford: Blackwell. Garmon, L. Writer The secret of the wild child. Garmon Producer , Nova. Goldin-Meadow, S. The resilience of language. New York: Psychology Press. Greenough, W. Induction of brain structure by experience: substrates for cognitive development. Nelson Eds. Hillsdale, NJ: Lawrence Erlbaum. Grimshaw, G. First language acquisition in adolescence: Evidence for a critical period for verbal language development.
Brain and Language , 63 , — Hakuta, K. Critical evidence: A test of the critical-period hypothesis for second-language acquisition. What are the challenges faced when introducing a programme of early language learning? Are they maintained when children begin with more formal methods? Is there a risk that teachers start again from the beginning, and that children lose the early enthusiasm?
How do schools meet the needs of their learners when some will have started early whilst others have not? What skills are required by those teaching languages to young learners? What kind of training do they need? Should there be specific qualifications? What are the specific language learning outcomes of early language learning?
What quality criteria can be used to assess early language learning? These are issues which require further research and exploration. How the work of the ECML contributes to early language learning A variety of ECML projects provide support for the development of professional competences in this area. Content and language integrated learning CLIL Increasingly in primary schools a language is taught using a CLIL approach — young learners use the foreign language to learn the content of other subjects.
Plurilingual and intercultural education Early language learning is intrinsically linked to plurilingual and intercultural approaches. Featured resources European portfolio for pre-primary educators. The plurilingual and intercultural dimension This portfolio is designed for educators and teachers in the pre-primary sector, either in initial or in-service training.
Current projects. Inspiring language learning in the early years This project aims to help teachers and other educators prepare young children to successfully face the challenges of a culturally and linguistically diverse world. It will provide them with learning and teaching resources and strategies which take existing linguistic repertoires into account in order to further develop the linguistic and intercultural competences of both learners and educators. View project pages. The approach has several features that make it unique: the models are implemented as computer programs, which enables clear-cut and quantitative predictions to be made; they learn from naturalistic input, made of actual child-directed utterances; they produce actual utterances, which can be compared with children's utterances; and they have simulated phenomena in several languages, including English, Spanish, and German.
Based upon the principles of Skinnerian behaviorism , RFT posits that children acquire language purely through interacting with the environment. RFT theorists introduced the concept of functional contextualism in language learning, which emphasizes the importance of predicting and influencing psychological events, such as thoughts, feelings, and behaviors, by focusing on manipulable variables in their context. RFT distinguishes itself from Skinner's work by identifying and defining a particular type of operant conditioning known as derived relational responding, a learning process that, to date, appears to occur only in humans possessing a capacity for language.
Empirical studies supporting the predictions of RFT suggest that children learn language via a system of inherent reinforcements, challenging the view that language acquisition is based upon innate, language-specific cognitive capacities. Social interactionist theory is an explanation of language development emphasizing the role of social interaction between the developing child and linguistically knowledgeable adults. It is based largely on the socio-cultural theories of Soviet psychologist Lev Vygotsky , and made prominent in the Western world by Jerome Bruner.
Unlike other approaches, it emphasizes the role of feedback and reinforcement in language acquisition.
Specifically, it asserts that much of a child's linguistic growth stems from modeling of and interaction with parents and other adults, who very frequently provide instructive correction. Another key idea within the theory of social interactionism is that of the zone of proximal development. Briefly, this is a theoretical construct denoting the set of tasks a child is capable of performing with guidance, but not alone.
Early language acquisition: cracking the speech code
As syntax began to be studied more closely in the early 20th century, in relation to language learning, it became apparent to linguists, psychologists, and philosophers that knowing a language was not merely a matter of associating words with concepts, but that a critical aspect of language involves knowledge of how to put words together—sentences are usually needed in order to communicate successfully, not just isolated words. In the s within the Principles and Parameters framework, this hypothesis was extended into a maturation-based Structure building model of child language regarding the acquisition of functional categories.
In this model, children are seen as gradually building up more and more complex structures, with Lexical categories like noun and verb being acquired before Functional- syntactic categories like determiner and complementiser. One influential proposal to the origin of these errors is as follows: the adult state of grammar stores each irregular verb form in memory as well as a "block" on the use of the regular rule for forming that type of verb. In the developing child's mind, retrieval of that "block" may fail, causing the child to erroneously apply the regular rule instead of retrieving the irregular.
A Merge linguistics -based Theory. In Bare-Phrase structure Minimalist Program , since theory-internal considerations define the specifier position of an internal-merge projection phases vP and CP as the only type of host which could serve as potential landing-sites for move-based elements displaced from lower down within the base-generated VP structure — e. Internal-merge second-merge establishes more formal aspects related to edge-properties of scope and discourse-related material pegged to CP.
See Roeper for a full discussion of recursion in child language acquisition. Generative grammar , associated especially with the work of Noam Chomsky , is currently one of the approaches to children's acquisition of syntax. In the principles and parameters framework, which has dominated generative syntax since Chomsky's Lectures on Government and Binding: The Pisa Lectures , the acquisition of syntax resembles ordering from a menu: the human brain comes equipped with a limited set of choices, from which the child selects the correct options by using the parents' speech, in combination with the context.
An important argument, which favors the generative approach, is the poverty of the stimulus argument. The child's input a finite number of sentences encountered by the child, together with information about the context in which they were uttered is, in principle, compatible with an infinite number of conceivable grammars. Moreover, few, if any, children can rely on corrective feedback from adults when they make a grammatical error, due to the fact that adults generally provide feedback regardless of whether a child's utterance was grammatical or not, and children have no way of discerning if a response was intended to be a correction.
Additionally, when children do understand that they are being corrected, they don't always reproduce accurate restatements. An especially dramatic example is provided by children who, for medical reasons, are unable to produce speech and, therefore, can never be corrected for a grammatical error but nonetheless, converge on the same grammar as their typically developing peers, according to comprehension-based tests of grammar.
Considerations such as those have led Chomsky, Jerry Fodor , Eric Lenneberg and others to argue that the types of grammar the child needs to consider must be narrowly constrained by human biology the nativist position. Recent advances in functional neuroimaging technology have allowed for a better understanding of how language acquisition is manifested physically in the brain, Language acquisition almost always occurs in children during a period of rapid increase in brain volume.
At this point in development, a child has many more neural connections than he or she will have as an adult, allowing for the child to be more able to learn new things than he or she would be as an adult. Language acquisition has been studied from the perspective of developmental psychology and neuroscience ,  which looks at learning to use and understand language parallel to a child's brain development. It has been determined, through empirical research on developmentally normal children, as well as through some extreme cases of language deprivation, that there is a " sensitive period " of language acquisition in which human infants have the ability to learn any language.
Several findings have observed that from birth until the age of six months, infants can discriminate the phonetic contrasts of all languages. Researchers believe that this gives infants the ability to acquire the language spoken around them. After such an age, the child is able to perceive only the phonemes specific to the language learned. The reduced phonemic sensitivity enables children to build phonemic categories and recognize stress patterns and sound combinations specific to the language they are acquiring.
In the ensuing years much is written, and the writing is normally never erased. After the age of ten or twelve, the general functional connections have been established and fixed for the speech cortex. Deaf children who acquire their first language later in life show lower performance in complex aspects of grammar. Assuming that children are exposed to language during the critical period,  it is almost never missed by cognitively normal children—humans are so well prepared to learn language that it becomes almost impossible not to. Researchers are unable to experimentally test the effects of the sensitive period of development on language acquisition, because it would be unethical to deprive children of language until this period is over.
However, case studies on abused, language deprived children show that they were extremely limited in their language skills, even after instruction. At a very young age, children can already distinguish between different sounds but cannot produce them yet. However, during infancy, children begin to babble. Deaf babies babble in the same order when hearing sounds as non-deaf babies do, thus showing that babbling is not caused by babies simply imitating certain sounds, but is actually a natural part of the process of language development.
However, deaf babies do often babble less than non-deaf babies and they begin to babble later on in infancy begin babbling at 11 months as compared to 6 months when compared to non-deaf babies. Prelinguistic language abilities that are crucial for language acquisition have been seen even earlier than infancy. There have been many different studies examining different modes of language acquisition prior to birth. The study of language acquisition in fetuses started back in the late s when different researchers discovered that very young infants could discriminate their native language from other languages.
In Mehler et al.
These results suggest there are mechanisms for fetal auditory learning, and other researchers have found further behavioral evidence to support this notion. Prosody is the property of speech that conveys an emotional state of the utterance, as well as intended form of speech whether it be a question, statement or command. Some researchers in the field of developmental neuroscience would argue that fetal auditory learning mechanisms are solely due to discrimination in prosodic elements.
Although this would hold merit in an evolutionary psychology perspective i. This ability to sequence specific vowels gives newborn infants some of the fundamental mechanisms needed in order to learn the complex organization of a language. From a neuroscientific perspective, there are neural correlates have been found that demonstrate human fetal learning of speech-like auditory stimulus that most other studies have been analyzing Partanen et al. In this same study, there was "a significant correlation existed between the amount of prenatal exposure and brain activity, with greater activity being associated with a higher amount of prenatal speech exposure," pointing to the important learning mechanisms present before birth that is fine-tuned to features in speech Partanen et al.
The capacity to acquire the ability to incorporate the pronunciation of new words depends upon many factors. Before anything the learner needs to be able to hear what they are attempting to pronounce. Another is the capacity to engage in speech repetition.
A lack of language richness by this age has detrimental and long-term effects on the child's cognitive development, which is why it is so important for parents to engage their infants in language. If a child knows fifty words or less by the age of 24 months, he or she is classified as a late-talker and future language development, like vocabulary expansion and the organization of grammar, is likely to be slower and stunted.
Two more crucial elements of vocabulary acquisition are word segmentation and statistical learning described above. Word segmentation, or the segmentation of words and syllables from fluent speech can be accomplished by eight-month-old infants. Recent evidence also suggests that motor skills and experiences may influence vocabulary acquisition during infancy. Specifically, learning to sit independently between 3 and 5 months has been found to predict receptive vocabulary at both 10 and 14 months of age,  and independent walking skills have been found to correlate with language skills around 10 to 14 months of age.
Studies have also shown a correlation between Socio-Economic-Status and vocabulary acquisition. Children learn, on average, ten to fifteen new word meanings each day, but only one of these words can be accounted for by direct instruction. It has been proposed that children acquire these meanings with the use of processes modeled by latent semantic analysis ; that is, when they meet an unfamiliar word, children can use information in its context to correctly guess its rough area of meaning.
For instance, a child may broaden the use of mummy and dada in order to indicate anything that belongs to its mother or father, or perhaps every person who resembles its own parents, or say rain while meaning I don't want to go out. There is also reason to believe that children use various heuristics to properly infer the meaning of words. Markman and others have proposed that children assume words to refer to objects with similar properties "cow" and "pig" might both be "animals" rather than to objects that are thematically related "cow" and "milk" are probably not both "animals".
According to several linguists, neurocognitive research has confirmed many standards of language learning, such as: "learning engages the entire person cognitive, affective, and psychomotor domains , the human brain seeks patterns in its searching for meaning, emotions affect all aspects of learning, retention and recall, past experience always affects new learning, the brain's working memory has a limited capacity, lecture usually results in the lowest degree of retention, rehearsal is essential for retention, practice [alone] does not make perfect, and each brain is unique" Sousa, , p.
In terms of genetics, the gene ROBO1 has been associated with phonological buffer integrity or length. Although it is difficult to determine without invasive measures which exact parts of the brain become most active and important for language acquisition, fMRI and PET technology has allowed for some conclusions to be made about where language may be centered. Kuniyoshi Sakai proposed, based on several neuroimaging studies, that there may be a "grammar center", where language is primarily processed in the left lateral premotor cortex located near the pre central sulcus and the inferior frontal sulcus.
Additionally, these studies proposed that first language and second-language acquisition may be represented differently in the cortex. Even the number of times an examinee blinked was taken into account during the examination process. It was concluded that the brain does in fact process languages differently, but instead of it being directly related to proficiency levels, it is more so about how the brain processes language itself. During early infancy, language processing seems to occur over many areas in the brain. However, over time, it gradually becomes concentrated into two areas — Broca's area and Wernicke's area.
Broca's area is in the left frontal cortex and is primarily involved in the production of the patterns in vocal and sign language. Wernicke's area is in the left temporal cortex and is primarily involved in language comprehension. The specialization of these language centers is so extensive that damage to them results in a critical condition known as aphasia.
Some algorithms for language acquisition are based on statistical machine translation. Prelingual deafness is defined as hearing loss that occurred at birth or before an individual has learned to speak. In the United States, 2 to 3 out of every children are born deaf or hard of hearing. Even though it might be presumed that deaf children acquire language in different ways since they are not receiving the same auditory input as hearing children, many research findings indicate that deaf children acquire language in the same way that hearing children do and when given the proper language input, understand and express language just as well as their hearing peers.
Babies who learn sign language produce signs or gestures that are more regular and more frequent than hearing babies acquiring spoken language.
Just as hearing babies babble, deaf babies acquiring sign language will babble with their hands, otherwise known as manual babbling. Therefore, as many studies have shown, language acquisition by deaf children parallel the language acquisition of a spoken language by hearing children because humans are biologically equipped for language regardless of the modality. Deaf children's visual-manual language acquisition not only parallel spoken language acquisition but by the age of 30 months, most deaf children that were exposed to a visual language had a more advanced grasp with subject-pronoun copy rules than hearing children.
Their vocabulary bank at the ages of 12—17 months exceed that of a hearing child's, though it does even out when they reach the two-word stage. The use of space for absent referents and the more complex handshapes in some signs prove to be difficult for children between 5 and 9 years of age because of motor development and the complexity of remembering the spacial use. Other options besides sign language for kids with prelingual deafness include the use hearing aids to strengthen remaining sensory cells or cochlear implants to stimulate the hearing nerve directly.
Cochlear Implants are hearing devices that are placed behind the ear and contain a receiver and electrodes which are placed under the skin and inside the cochlea. Despite these developments, there is still a risk that prelingually deaf children are may not develop good speech and speech reception skills. Although cochlear implants produce sounds, they are unlike typical hearing and deaf and hard of hearing people must undergo intensive therapy in order to learn how to interpret these sounds.
They must also learn how to speak given the range of hearing they may or may not have. However, deaf children of deaf parents tend to do better with language, even though they are isolated from sound and speech because their language uses a different mode of communication that is accessible to them; the visual modality of language.
Although cochlear implants were initially approved for adults, now there is pressure to implant children early in order to maximize auditory skills for mainstream learning which in turn has created controversy around the topic. Due to recent advances in technology, cochlear implants allow some deaf people to acquire some sense of hearing.
There are interior and exposed exterior components that are surgically implanted. Those who receive cochlear implants earlier on in life show more improvement on speech comprehension and language. Spoken language development does vary widely for those with cochlear implants though due to a number of different factors including: age at implantation, frequency, quality and type of speech training. Some evidence suggests that speech processing occurs at a more rapid pace in some prelingually deaf children with cochlear implants than those with traditional hearing aids.
However, cochlear implants may not always work. Research shows that people develop better language with a cochlear implant when they have a solid first language to rely on to understand the second language they would be learning. In the case of prelingually deaf children with cochlear implants, a signed language, like American Sign Language would be an accessible language for them to learn to help support the use of the cochlear implant as they learn a spoken language as their L2.
Without a solid, accessible first language, these children run the risk of language deprivation, especially in the case that a cochlear implant fails to work. They would have no access to sound, meaning no access to the spoken language they are supposed to be learning. If a signed language was not a strong language for them to use and neither was a spoken language, they now have no access to any language and run the risk of missing their Critical period.