Throughout the article titled “Domain-General Learning Capacities,” contributors Jennv Saffran and Erik Thiessen employ evidence found in previous studies in order to support the argument that language acquisition in humans involves more domain-specific processes, implying “an innate, modular, knowledge system” (Saffran and Thiessen, 2008, pg. 80), than domain-general processes, implying “a set of generalized simple learning devices that can operate over any types of input” (Saffran and Thiessen, 2008, pg. 79). Saffran and Thiessen’s assertion suggests that infants are born with a language acquisition device, which is an innate biological ability accessible to all humans to acquire and develop language (Language Acquisition Device). In this paper, however, I intend to argue that infants are born depending on their domain-general ability to acquire language, but, after only several months of infancy, depend primarily on their domain-specific ability in order to acquire language. Ultimately, all humans are born with a language acquisition device, but infants need time to activate it.
Researchers commonly analyze language acquisition in humans through utilizing evidence found from speech category distinction tests. According to Saffran and Thiessen, “Infants must learn which acoustic distinctions are productive in their linguistic environment … When presented with a set of exemplars with a highly variable distribution, infants form broad, inclusive categories. When familiarized with a more focused distribution of exemplars, infants form categories with tighter boundaries” (Saffran and Thiessen, 2008, pg. 72). Such findings convey that infants are able to identify a wider range of sounds that could have linguistic relevance early on in infancy, but once an infant has had several months of exposure to their native language, they are only able to identify sounds as linguistically relevant only if they are able to recognize them as linguistically relevant in their native language. Furthermore, these findings show that infants rely on their more general, perceptive abilities before accessing their language acquisition device, for infants recognize essentially all verbal sounds as potentially having linguistic relevance before being able to recognize the linguistically relevant sounds that they will soon learn to communicate with.
Another way that researchers analyze language acquisition in humans is through using evidence found from word segmentation tests. Infants tend to begin learning how to distinguish different words through transitional probabilities (Saffran and Thiessen, 2008, pg. 74), which allow infants to make an inference about whether a word has ended or has another part to it depending on the sound that they most recently heard. Saffran and Thiessen remark, “in English, stress is correlated with word beginnings, and between 8 and 9 months, infants begin to treat stressed syllables as word onsets … While young infants favor transitional probabilities over stress cues, older infants rely more on stress cues” (Saffran and Thiessen, 2008, pg. 74). Stress only has linguistic relevance depending on the language at hand, so infants’ transition from relying on transitional probabilities to relying on stress cues to distinguish words indicates that infants must first be able to recognize whether or not stress is a linguistically relevant factor before they may use it to distinguish words. Infants must have exposure to some language and begin learning about the linguistically relevant sounds of their respective language for their language acquisition device to be activated.
In a study involving multiple experiments titled “Rule Learning by Seven-Month-Old Infants” conducted by G. F. Marcus, S. Vijayan, S. Bandi Rao and P. M. Vishton, it was discovered that “7-month-old infants attend longer to sentences with unfamiliar structures than to sentences with familiar structures” (Marcus et al., 1999, pg. 77). Additionally, “The design of the artificial language task used in these experiments ensured that this discrimination could not be performed by a system that is sensitive only to transitional probabilities” (Marcus et al., 1999, pg. 77). The 7-month olds in this experiment have had several months of exposure to language at the time the experiment was conducted, but the language they heard in this experiment was made-up, so their lack of previous experience prohibited them from using transitional probabilities to distinguish words. Once infants have had adequate exposure to language, however, they are able to derive certain rules and grow into having the ability to distinguish structures that are either linguistically relevant or not linguistically relevant. The overarching finding from this study conveys that infants are able to deduce rules in language at around the same time that they only attend to sounds in their own language and begin depending more on stress cues than on transitional probabilities. Consequently, it seems as though the language acquisition device of infants are consistently activated after several months of learning about different aspects of language.
Evidence that infants are born depending primarily on domain-general processes to acquire language but ultimately depend primarily on domain-specific processes in order to acquire language is important in that such findings begin to bridge the gap between the non-nativist theory of language and the nativist theory of language. From the information that I have uncovered regarding this debate, I contend that humans do in fact have an innate capability to acquire language, but infants must begin to learn about the foundational attributes of language before accessing the abilities that the language acquisition device provides.
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References
Language Acquisition Device. Retrieved from https://www.alleydog.com/glossary/definition.php?term=Language+Acquisition+Device+%28LAD%29
Marcus, G. F., Vijayan, S., Rao, S. B., & Vishton, P. M. (1999). Rule Learning by Seven- Month-Old Infants and Neural Networks. Science, 284(5416), 77-80. Retrieved from http://www.jstor.org/stable/2897195
Saffran, J. R., & Thiessen, E. D. (2008). Domain-General Learning Capacities. Blackwell Handbook of Language Development, 68-81.