6. The Neurological Correlates of Language Acquisition: Current Research

Research and speculation on the neurological correlates of language acquisition have been growing at a rapid and accelerating rate, and it is increasingly difficult for the nonspecialist to adequately cover and evaluate current discoveries. This paper will attempt to review some of the current research in this area, that dealing with what is perhaps the most obvious neurological phenomenon relating to language, cerebral dominance, or lateralization, and attempt to update the reader on recent progress and suggest some interpretations of this research.

Cerebral Dominance

It is by now a well-established finding that for most people (practically all right-handers and most left-handers), the two sides of the cortex perform different functions. As Table 1 indicates, the left hemisphere

    Table 1. Functions of the two hemispheres
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Left hemisphere                  Right hemisphere
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Language                         Spatial relations
Time-related functions           "Gestalt" perception
                                 Part-to-whole judgments
"Propositional" thought           Music
                                 "Appositional" thought
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is responsible for most linguistic performance in adults. Recent studies strongly suggest that the left brain is also involved in certain non- linguistic functions, specifically those related to the perception of time: for example, the left hemisphere is superior to the right in judging temporal order, or deciding which of two stimuli was presented first (see, for example, Carmon and Nachshon, 1971; Papcun, Krashen, Terbeek, Remington, and Harshman, 1974). The "other side of the

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