Psychology of Second Language Acquisition by Daniel P. Auld
One debatable aspect of second language acquisition is when is the ideal time for second language instruction to begin. Lenneberg was the first to discuss the critical period for language acquisition, which proposes that the most effective learning of a second language takes place during early childhood and ends around puberty (as cited in Newport, 1991; Bernicot 1989). There are two schools of thought on the cognitive changes occurring during the critical period as described by Newport (1991). The first school asserts that targeted domains (such as language acquisition) are at their peak of learning at certain ages (at childhood for language acquisition), after which the ability for the domain to be mastered diminishes over time. The second school contends that when one is in the early stages of cognitive development, innumerable domains are ready to be conquered. As one focuses on one domain, however, the mechanism for learning increases in that domain while other domains remain stagnant and undeveloped. Given that adults begin studying a foreign language and gain proficiency and even fluency, the second theory seems more adequate in explaining the critical period of language acquisition.
Another factor contributing to the critical period involves differences in learning strategies between children and adults. In the Less is More Hypothesis proposed by Newport (1991), children achieve a better morphology for the language because they process language in small pieces and gradually increase cognitively and in the amount of material to which they are exposed as they mature. Adults, however, extract at a word or sentence level and then find that they have difficulty putting it together in a foreign language (Newport, 1991).
Recognizing that adults and children approach language learning differently, Chen and Leung (1989) classified them among three groups based on their experimental studies. The first group, based upon a word-association hypothesis, is a direct word-to-word association from the native language to the foreign language, which is typical of adults learning a new language. The second is a concept-mediation hypothesis, where the two languages are created as separate systems in the mind and are linked through a conceptual system, common to children being raised with two languages. The third hypothesis is a mixture of the first two hypotheses. Here one begins with the word-to-word, but gradually, as a distinct system develops for the second language, the learner converts to the concept-mediation approach. More specifically, as one reaches a certain level of mastery of a foreign language, the individual essentially establishes an independent system of the second language and no longer depends upon the first language for clarification of the second. This is represented by the novice fluent in one language learning a second, but who ultimately gains fluency parallel to a bilingual native to the two languages.
Bernicot, J. (1998). Communication and language development. In A. Demetriou, W. Dosie & C.F.M. van Lieshout (Eds.) Life-Span Developmental Psychology (pp. 137-178). New York: John Wiley & Sons.
Chen, H. & Leung, Y. (1989). Patterns of lexical processing in a nonnative language. Journal of Experimental Psychology: Learning, Memory, and Cognition, 15, 316-325.
Newport, E. (1991). Contrasting conceptions of the critical period of language. In S. Carey & R. Gelman (Eds.), The epigenesis of mind: essays on biology and cognition (pp. 111-130). Hillsdale, NJ: Lawrence Erlbaum Associates.
Daniel P. Auld, MS is a doctoral candidate in Educational Psychology in the Division of Psychological and Educational Services at Fordham University.
Neural Mechanisms for Language Processing in Bilinguals by Caroline J. Hoang
Are there really distinct language systems in bilinguals? The answer is both yes and no. The most convincing data supporting independent systems are reported in clinical case studies which show either selective impairment and/or differential recovery of one or more languages in multilingual aphasic patients (Nilipour & Ashayeri, 1989; Paradis & Goldbum, 1989). At the anatomical level, however, many studies show that the brain activation patterns of bilingual persons during language processing can 1) overlap between languages, suggesting a shared system, or 2) be restricted to one language, suggesting separation. Moreover, studies using stimulation of specific brain areas in presurgical patients have shown both selective and shared disruption of the first and second language (Ojemann & Whitaker, 1978).
So, how can language systems in fluent bilinguals appear to be shared AND independent? The answer lies in the details of the experiments. First, one must consider the technical limitations in studies that image brain activation. More specifically, different techniques (e.g. functional magnetic resonance imaging, or fMRI, versus positron emission tomography, or PET) have different image resolutions, which can yield varying results (as discussed in Illes et al., 1999). In addition, although the pattern of brain activation may be similar between languages, one must consider that the pattern represents thousands (if not hundreds of thousands) of individual neurons. Thus, while the pattern of activation may be similar on a macroscopic level, the same may not necessarily be true at a microscopic (or single cell) level. Second, one must consider the type(s) of language processing under examination. Literature published thus far suggests that phonological (Marian et al., 2003) and semantic (for review, see Illes et al., 1999) processing are shared systems in fluent bilinguals while lexical processing is a separate system (Marian et al., 2003).
With both shared and separate language processing systems, how do bilinguals process one language without interference from the other? This is presently a very hot topic in the field of language and cognition, with focus on the following question: Is bilingual lexical processing selective for one language or is there parallel lexical processing in the two languages? It has been proposed that selective processing consists of a "language switch" mechanism that activates the appropriate lexicon while "switching off" the inappropriate lexicon (Gerard and Scarborough, 1989; MacNamara and Kushnir, 1971). This is supported by a behavioral study in bilinguals showing that a lexical decision task took less time to complete following a same-language repetition exercise compared to a different-language repetition exercise. The longer time required for the lexical decision in the latter case was suggested to result from "switching off" one lexicon and "switching on" the other (Gerard and Scarborough, 1989). Other studies using different experimental protocols also support the selective activation theory but reviewing them is beyond the scope of this article. For more information, see Marian and Spivey, 2003
In the case of parallel processing, it is proposed that both lexical systems in bilinguals are simultaneously active and compete for recognition. This is supported by a behavioral study which required Russian-English bilingual subjects to locate an object under monolingual conditions (Marian and Spivey, 2003). More specifically, subjects were asked in either Russian or English to pick up one of four objects placed within their view while their eye movements were simultaneously tracked by camera. In one of the experimental paradigms in English, subjects were asked to pick up an object whose name in English (e.g. "shovel") bore phonological similarity to the name of one of the other objects in Russian (e.g. "sharik", the word for balloon). The other two objects were filler objects with no phonological overlap in either language. Interestingly, based on their eye movements, subjects became distracted by the balloon before they picked up the shovel. This suggested that both the language systems for English and Russian were simultaneously active, thereby supporting the idea of parallel activation. Additional studies using different experimental protocols also support the parallel processing theory, For more information, please see Marian and Spivey, 2003.
So which hypothesis is right? The answer, according to Marian et al., 2003, is probably a little bit of both. Their parsimonious hypothesis proposes that language processing in bilinguals initially takes place with parallel activation of the lexicons of both languages but, with time to process context, the lexicon of the appropriate language becomes completely activated. The magnitude of parallel processing can be influenced by phonological overlap of words between languages, the frequency with which a word is used in each respective language, and the level of proficiency a bilingual person has for each language (Marian and Spivey, 2003). And though ultimately complete activation is limited to the lexicon of one language, it is possible that the lexicon of the other language remains active but to smaller degree (Marian and Spivey, 2003).
How does this apply to Céline and the barley "incident"? I would propose that Céline goes to the job with both languages primed for activation. Because Céline is highly proficient in both French and English (in addition to being a very clever bunny), she makes flawless transitions between the languages (i.e. flawlessly discerns and activates the appropriate lexicon). When she cannot retrieve the French equivalent for barley, however, she panics inside her head in English while speaking in French effortlessly. This results from the brain’s ability to multi-task (i.e. parallel processing of different brain functions; for example, driving a car and holding a conversation with your friend simultaneously). In this case, Céline’s brain manages to multi-task interpreting English to French in the dominant French lexicon with emotions/thoughts of panic in the less active but distinct English lexicon.
Gerard, L.D. and Scarborough, D.L. (1989). Language-specific lexical access of homographs by bilinguals. Journal of Experimental Psychology: LMC, 15, 305-313.
Illes, J., Francis, W.S., Desmond, J.E., Gabrieli, J.D.E., Glover, G.H., Poldrack, R., Lee, C.J., and Wagner, A.D. (1999). Convergent cortical representation of semantic processing in bilinguals. Brain and Language, 70, 347-363.
MacNamara, J. and Kushnir, S. (1971). Linguistic independence of bilinguals: The iput switch. Journal of Verbal Learning and Verbal Behavior, 10, 480-487.
Nilpour, R. and Ashayeri, H. (1989). Alternating antagonism between two languages with successive recovery of a third in trilingual aphasic patient. Brain and Language, 36, 23-48.
Ojemann, G.A. and Whitaker, H.A. (1978). The bilingual brain. Archives of Neurology, 35, 409-412.
Paradis, M and Goldblum, M.-C. (1989). Selective crossed aphasia in a trilingual aphasic patient followed by reciprocal antagonism. Brain and Language, 36, 62-75.
Marian, V. and Spivey, M. (2003). Competing activation in bilingual language processing: within and between-language competition. Bilingualism: Language and Cognition, 6(2), 97-115.
Marian, V., Spivey, M., and Hirsch, J. (2003). Shared and separate systems in bilingual language processing: converging evidence from eyetracking and brain imaging. Brain and Language, 86, 70-82.
Caroline J. Hoang, PhD is a research fellow in the Department of Neuroscience at the Albert Einstein College of Medicine of Yeshiva University.