Language and Brain Development
Language distinctively distinguishes man from other animals. Language is the single most important element in the understanding of humanity, as well as what makes humans what they really are (Fromkin, Rodman &Hyams, 2009). Fascinating, however, is the fact that regardless of the complexity of language as an aspect of human cognition, children easily grasp different aspects of language much before they can grasp other social and motor aspects of life (Christiansen &Chater, 2008). This begs the question of whether language is indeed nature or nurture driven. The question therefore brings into focus two schools of thought over the acquisition of language among children. One of the schools of thought suggests that the brain mechanism for the acquisition of language have evolved over time according to the natural selection. The other view is that the mechanisms are not a product of adaptive evolution, but natural occurrences within the human body (Christiansen &Chater, 2008). Regardless of these divergent views, what is true is the fact that language and the brain have an intimate connection. The intimacy of the connection between the brain and language is so close that any injury to these parts of the brain areas leads to a disruption of language (Fromkin, Rodman &Hyams, 2009). This alone provides evidence to the close intimacy between the brain and language. Even more is the fact that evidence points to the role of language exposure to the normal development of the brain. In this paper therefore, we look at the relationship between the language and brain development, some of the theories of language acquisition among children and the effects of some brain disorders on language development and acquisition with the view of understanding the close relationship between language and the brain.
Language plays an important role in the normal development of a child. According to Fromkin, Rodman and Hyams (2009), although children do not necessarily need language instruction, they do need an exposure to the language for normal development. It is the reason, therefore, that most of the children who do not receive sufficient linguistic exposure during their formative years do not eventually reach native-like competence in the particular language (Fromkin, Rodman &Hyams, 2009). Attestation to this fact is the discovery by imaging studies showing the effect of late exposure to brain development; it (late exposure) changes the basic organization of the brain for language.
It is hypothesized that the formative years (also known as critical period) are important for language acquisition, as the brain is biologically primed to receive/learn language at this time. It is the argument that at this period learning of the language proceeds easily and swiftly without any external assistance (Fromkin, Rodman &Hyams, 2009). Missing this critical period, however, is catastrophic as it not only becomes difficult to learn the language, but also becomes difficult to achieve fully native-like grammar. Moreover, deprivation of language at this critical period has effect on the brain. Children without exposure to language at the period show “atypical patterns of brain lateralization” (Fromkin, Rodman &Hyams, 2009, p. 62).
Case studies’ evidence shows the necessity of language in brain development, particularly in the processing and acquisition of language grammar. Genie is a good example of a child who had remained isolated during the critical formative years (birth-middle childhood). Exposed to human contact at 14 years, Genie was unable to speak, and although she was able to speak after years of language instruction, she was still unable to acquire grammar (Fromkin, Rodman &Hyams, 2009). Her speech was a string of content words, with the inability to use grammatical words such as articles and conjunctions in her speech. Moreover, brain lateralization experiments pointed to right hemisphere lateralization of her brain (Fromkin, Rodman &Hyams, 2009). Even more is that although Genie’s brain showed no signs of damage, she was unable to use grammar. The explanation here is “that after the critical period, the usual language areas functionally atrophy because of inadequate linguistic stimulation” (Fromkin, Rodman &Hyams, 2009, p. 63).
Brain comparisons between children exposed to language at the critical period and those not exposed to language show a big difference between the two. There is a stark difference in the brain asymmetry between the two. This confirms the argument that “children cannot fully acquire language unless they are exposed to it within the critical period—a biologically determined window of opportunity during which time the brain is prepared to develop language” (Fromkin, Rodman &Hyams, 2009, p. 64). Even more is the link between the critical period and brain lateralization. Fromkin, Rodman and Hyams inform that although the brain’s architecture is in such a way that the areas of the left hemisphere are primed for language acquisition, “the normal process of brain specialization depends on early and systematic experience with language” (p. 64). This is a view shared by Kuhl (2010), who contends, “exposure to language in the first year of life influences the brain’s neural circuitry even before infants speak their first words” (713). Evident therefore is the fact that language acquisition is crucial to, and perhaps plays a vital role in triggering the realization of normal cerebral lateralization, for more cognitive functionalities, and not specifically language.
The significance of exposure to language in brain development and language development cannot be overemphasized. Linguists consider the knowledge and competence for human language as an acquisition with various modalities and means of access. Many of these linguists consider speaking, singing and comprehension of language as primary faculties of language—innate and biologically determined (Sakai, 2005). On the other hand, abilities such as reading and writing according to linguists are secondary. A pointer to this is the fact that children learn their first language through exposure to it and develop exponential linguistic knowledge. In contrast, reading and writing as language skills require conscious effort and repetition largely at an institution with an instructor and a syllabus that determines what is learnt at whichever level (Sakai, 2005).
Noteworthy is that with the acquisition of language faculties, there are considerable changes in the brain volume. According to Sakai (2005), with increased development of the first language faculties, the brains volume also increases, particularly in the first years of the development of these language faculties. Language acquisition therefore helps in further development of the brain not only for the purpose of language, but also for other complex tasks during the development process.
What is fascinating about language and brain development is the effect that exposure to language has on the development of the brain. As aforementioned, a child takes in speech at birth. The child is able to initiate a conversation with the mother or caregiver by looking into the eyes of these two, as well as terminate the conversation by looking away. However, in listening to speech, the baby will prefer sounds with happy connotations and shuns sounds with negative or neural emotions. It is perhaps for this reason that the baby cries when one raises their voices, while they smile or laugh at soft sounds (Ko, 2015). With constant exposure to language therefore, the brain’s language areas get stimulated. More exposure to the language therefore stimulates the growth of these language areas and to an extent, other areas of the brain. Consequently, before the child gains the ability to speak and use language, the child already has an understanding of the emotional undertones of a language.
Exposure to language at an early age does not only affect the development of the brain but also the acquisition of a second language. Research has indicated that exposure of children to more than one language leads to proficiency in both languages (Sakai, 2005; Watterndorf et al., 2014). Moreover, the acquisition of a second language in early life has “not only been proposed to promote flexible learning of multiple, new speech items in bilingual infants, but is also supposed to advance cognitive control and selection abilities in children and adults” (Watterndorf et al., 2014, p. 49). Perhaps the best use and effect of bilingualism is in the brain functions. According to Sakai (2015), the left frontal region of the brain is the grammar center. These are stimulated when a child is exposed to more than one language during the critical period. Thus, while the capacity to learn another language is at a different area of the brain, exposing children to two different languages brings the storage of the second language at the same place as the first language (Kennedy, 2006). This fact makes it easier for children to not only learn a second language, but also attain the same level of proficiency as the native speakers in both languages. This is contrary to adults, who even after lengthy exposure to the language remain incapable of achieving native-like pronunciation in the second language (Bialystok, 2011).
Apart from the ability to speak different languages, bilingualism has a great impact on the brain and its development. Kennedy (2006) informs, “in response to second language acquisition (SLA) and use, the human brain undergoes cortical adaptation to accommodate multiple languages either by recruiting existing regions used for the native language (Ll), or by creating new cortical networks in distinct adjacent areas of the cortex to handle certain functional aspects of L2”(p. 475). Even more is that with the inferior frontal gyrus responsible for the activation and learning of a language and therefore increasing the proficiency level, exposure to two different languages increases the level of inferior frontal gyrus activation. Accordingly, therefore, cortical activations increase at the onset of language acquisition. Exposing a child to two languages exponentially increases these activation levels until the child reaches proficiency of both languages. The brain then maintains these activations to allow for the consolidation of the linguist competence in both languages. After the attainment of proficiency in the two, the activation decrease, while maintaining the proficiency levels (Sakai 2005).
Yet the perquisites of bilingualism do not stop at improved inferior frontal gyrus activation but extend to improved cognition. According to the Work and Family Life Journal (2012), bilingualism forces the brain to be continually in conflict with itself. This continuous conflict is apparently advantageous to the brain as it strengthens the brains cognitive muscles, and thus improving some aspects of cognition. Evidence provided by different research point to better problem solving and cognitive control among bilinguals in comparison with their monolingual counterparts (Bialystok, 2011; Friederic, 2006; Khul, 2010). Bilinguals additionally outperform monolinguals in monitoring tasks given their ability to stay constantly aware of their environment. Moreover, most bilinguals constantly anticipate the use of either of the languages, making them more alert than their monolingual counterparts.
Even more advantageous to bilinguals is the onset of some diseases. The Work and Family Life Journal (2012) reports that individuals with higher degree of bilingual proficiency “were more resistant than others to the onset of dementia and other symptoms of Alzheimer’s disease.The higher the degree of bilingual proficiency, the later the age of onset” (p. 3). Part of the reason for bilinguals’ advantage over some of these diseases is the ability of bilingualism to slow down some mental functions. It is for this reason that bilinguals are diagnosed with Alzheimer’s disease much later among the elderly as well as report the onset of the disease’s symptoms more than five years after their monolingual counterparts. Therefore, while bilingualism keeps the brain active, it slows down some negative effects that come with the brain remaining dormant for a long time. It therefore keeps the brain active and therefore contributes to cognitive reserve through the engagement and intense activity (Simmons, 2011).
Relatedly, bilingualism has a great effect on cognitive aging. Thus, apart from protracting the onset of diseases, the ability to speak more than one language protects the speakers from the effects of cognitive aging (Bialystok, Craik & Luk, 2013). This is particularly because of the ability of bilinguals to inhibit incongruent stimuli in the processing of information. Therefore, while it is possible for both monolinguals and bilinguals to learn how to disregard any distractive effects of interfering stimuli, bilinguals have an upper advantage learning how to deal with the inhibition more rapidly (Bialystok, Craik & Luk, 2013).
Research into the effects of bilingualism on the brain further indicates the positive effect it has on mental function apart from the ability to keep dementia and Alzheimer’s disease at bay. According to Simmons (2011), bilingualism juggles the brain and in so doing improving the individual’s ability to multitask. It (bilingualism) also helps in keeping the brain in shape and bolstering mental function. Moreover, bilingualism additionally bolsters some skills in that bilinguals outperform monolinguals in mental tasks such as removal of irrelevant information while focusing on relevant information, as well as being better off at prioritizing (Simmons, 2011).
The advantage further extends to performance of difficult task or conditions that require deeper brain concentration. Bialystok, Craik and Luk (2013) enthuse, “bilingual young adults outperformed their monolingual counterparts on the directional arrow Simon task, but only on the condition that included more monitoring and switching than a simpler condition” (p. 245). Conditions involving any congruent and incongruent trials therefore brought the mental superiority of the bilinguals given their higher mental cognition and work. This points to an advantage by the bilinguals as they reflect a “more efficient monitoring system for conflict resolution, in that bilinguals may be better at determining when the misleading information can be safely ignored” (Bialystok, Craik & Luk, 2013, p. 245).
Bilingualism additionally has significant effect in both adults and children executive control as well as the ability to suppress a pre-potent response (Khul, 2010). Adult bilingual speakers have exhibited superior executive control, a skill that is also visible among bilingual children. It is conclusive therefore from these observations that cognitive skills are closely related to phonetic leaning at the initial stages of phonetic development (Khul, 2010). The idea here is that with bilingualism, these individuals have a greater attention span given the brains development in balancing the conflicting activations of bilinguals in comparison to monolinguals; bilinguals are therefore much better in conflict resolution (Bialystok, 2011).
The flexibility of the brain language centers and other areas related to other cognitive functions is one fascinating factor in reference to the bilingualism. By learning a second language, the brain’s language centers are expanded and pressured into accepting the second language. This is especially true for individuals learning the second language after the critical period. By putting pressure on the brain’s language areas in learning a second language, new areas of the brain are developed. This development enhances the brains natural ability to not only focus, but also process information faster, as well as entertain different possibilities to a situation. Bilingualism, consequently acts as an exercise to the brain; the language mirroring effect helps sharpen the mind, improve an individual’s communication skills as well as improve decision-making.
Aside from the bilingualism and the development of the brain as well as the advantage it brings to the bilingual speaker is the very process of language acquisition. Herein, the debate remains on the role of nature and nurture on the child’s acquisition of language. The paper has discussed some of the mental developmental changes triggered by exposure to language. The discussion on the acquisition of language on the other hand remains controversial with proponents of language as nature driven insisting that language acquisition comes naturally, while proponents of nurture argue for the environment as a rich source of language from where a child picks his/her language. One of the notable theories pegged on nurture as the most important element in language acquisition is the behaviorist theory. Tracing back to JB Watson’s habit formation hypothesis, the behaviorist theory associates a particular response with a corresponding stimulus, which in the end constitutes a habit (Islam, 2013). In their argument, behaviorists indicate that a habit is formed at the regular linking of a response to a specific stimulus.
Among the best-known behaviorist theorists was Skinner, who insisted on the consequence of the response to the stimulus. Following Pavlov’s classical conditioning with dogs and Thorndike’s experiment with cats in a puzzle box, behaviorists see the stimulus as the very basic avenue for acquisition of language (Islam, 2013). It is the claim of the behaviorists that all animals, inclusive of humans, have an innate set of instinctive responses to external stimuli. With reference to language learning, Skinner argued for operant conditioning as a means of language acquisition where reinforcement and punishment increase or decrease the likelihood of adapting a behavior (Islam, 2013). Positive reinforcements (rewards) therefore encourage and reinforce the behavior and in so doing strengthening the association between the two. In learning, according to Skinner, imitation and reinforcement play instrumental roles. Thus, the learner (child) copies a behavior to a point that it becomes automatic and reinforcement, where either punishment or reward only encourages the appropriate responses (Islam, 2013).
In relating Skinner’s theory to language learning, the stimuli in this case are utterances within the child’s environment, which demand some response from the child. The family members, teacher or caregiver then reinforces the child’s appropriate responses through rewards such as praise (Islam, 2013). The result becomes the prospect of the behavior increasing. On the other hand, with negative reinforcement, the possibility of making some utterances decreases, with less imitation, which eventually leads to the stoppage of the inappropriate imitation. For Skinner therefore, language becomes a habit (Islam, 2013).
Although many have poked holes on the argument of the theory, especially in relation to its failure to explain the creative production among people of language, it helps to explain some issues in language. These include language features such as pronunciation as having been imitated from the surrounding environment. An additional fault on the theory is the aspect of the learners thinking and mind. By emphasizing on imitation alone, the theory does not take into consideration other aspects of language such as the defined sets of structure and rule. Moreover, it fails to acknowledge that the learner has a mind of his/her own, which plays an important role in language acquisition and use (Islam, 2013).
The alternative theory to the behaviorist theory stemmed from the criticism of the behaviorist theorists. This emphasizes on nature as a determinant of language acquisition. Called the mentalist theory, the theory has its leader in Noam Chomsky, who argued that the extension of laboratory results on animals to human beings did not show anything regarding the acquisition of language among humans (Islam, 2013). Mentalist theorists particularly take issue with the supposed passive position of the child in learning a language. In their argument, behaviorists site the creativity of child language, in which children make utterances never heard before, and can therefore not be a result of imitation as argued by the behaviorist (Islam, 2013). Mentalists, Chomsky in particular, have laid claim on the fact that the child’s knowledge of language is innate and derived from Universal Grammar (Hashamdar, 2012). The Universal Grammar (UG) according to Chomsky dictates the very basic form of a natural language can take.
The UG, according to Chomsky “exists as a set of innate linguistic principles which comprises the initial state and which controls the form which sentences of any given languages can take” (Islam, 2013, p. 503). The biological ability, for Chomsky, is the language acquisition device (LAD) contains the language principles common to all human languages. Through his ability therefore, children are capable of constructing sentences in their native language by mastering the grammar rules. Moreover, by possessing these grammar principles, children tend to use the same principle even in learning the second language (Heidar, 2012).
Thus, for LAD’s activation, only the language input is necessary. According to mentalists, the child has an innate ability to learn any language, and that only humans have the ability to access this device. This is evidenced by the fact that regardless of their intellectual capability, as well as their social living, chimpanzees are still incapable of mastering language (Heidar, 2012). Even more is that regardless of them passing the critical period of grammar learning, the children bred in isolation such as Genie, as aforementioned, skill had the capability of learning and producing language, although absent of the grammatical elements (Fromkin, Rodman &Hyams, 2009). Nature therefore plays an important role in the acquisition of language, to enable the child produce sentences never heard. The language input is hence of importance for the child, whose mental faculties sort the language to identify the type of language and the specific rules that govern such a language. The complexity of language, and especially for multi-linguals, can therefore not be a product of imitation as fronted by behaviorist theorists. Only an innate system of language processing and compartmentalization can enable the production of unique sentences that children, and later as they become adults, produce. This in essence points to an innate capability, which Chomsky refers to as the language acquisition device.
As the center of human processes and reasoning, the brain plays a major role in the everyday activities of humans. It however requires development to be able to perform all these functions properly. Human language has been known to activate the development of the brain and therefore aiding in the very fundamental purpose of the brain. Language forms the very basis of human communication. Whether in sign or gestures, language remains the core to human communication. More than communication, language triggers the development of the brain, not only in the acquisition of the grammatical rules of any language, but for efficient motor and cognitive performance. The ability to speak two or more languages on the other hand, is even more advantageous to the speakers, not only in terms of communication but also in enhancing some skills. Executive control, multitasking, and decision-making are all enhanced with bilingualism. The benefits of bilingualism extend to mental health where bilingualisms plays a role in slowing some mental functions while keeping the brain active and in so doing slowing the diagnosis of some mental illness among the elderly such as dementia. Therefore, although bilingualism does not in any way cure the mental illness, it slows down its diagnosis and symptoms by four and five years respectively, making it not a linguistic interference as earlier suggested by some linguists. In looking at language acquisition, many theories have tried to explain how humans acquire language. The debate over nature and nurture in acquisition of language presents two theories: behaviorist and mentalist theories of language acquisition. Led by Skinner, behaviorists argue that humans acquire language through imitation, where both negative and positive reinforcements establish language into a habit. Conversely, mentalists argue that humans have an innate ability to acquire language. This innate ability, according to Noam Chomsky allows humans to learn natural language principles and produce an infinite number of unique sentences. Conclusively therefore, language is unique to humans, and they undergo a process in acquisition of language. In itself, language triggers the development of different human faculties within the brain, a fact that make it (language) uniquely human.
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