Second Language Acquisition and Second ... - Stephen Krashen

might expect some cases of aphasia involving second languages to involve the right
hemisphere, which is precisely what Galloway found. Also, it is quite possible that
the subjects used in the experiments listed in (2) above that did not show L1-L2
differences utilized subjects of advanced second language competence (probably
true of all but Carroll, 1978; see discussion below). Finally, Obler's hypothesis
allows a neat parallel between first and second language acquisition, both involving
right hemisphere participation in early stages.
There are, however, the inevitable problems and potential counter-examples. In a
recent TESOL presentation, Carroll (1978) reported a clear right-ear advantage
using dichotic listening for Spanish as a foreign language, the second language in
fact appearing to produce a greater right-ear advantage than English, the first
language. A possible explanation is that foreign language learning may involve the
conscious grammar, which may be located in the left hemisphere (but not
necessarily in the language areas). Indeed, conscious grammar use may be heavier
in the second language than the first language, accounting for the greater right-ear
advantage in English. Thus, we might refine the stage hypothesis: it would be
proposed that the right hemisphere plays a role in early language acquisition, not
language learning. But this does not solve everything. First, dichotic listening uses
words, not sentences: is the conscious grammar called up when only words are
perceived in isolation? Also, Carroll reported that those with more "natural"
exposure to Spanish before age 6 showed less of a right-ear advantage, which would
appear to be consistent with the stage hypothesis, but another older group of
"informal" acquirers showed a strong right-ear advantage for the second language.
Thus, age might be a factor: Carroll (personal communication) reminds us that the
Gaziel et al. subjects were also fairly young (age 12 in the grade 7 group).
Another potential counter-example is Rogers, TenHouten, Kaplan, and Gardiner
(1977). Using EEG with bilingual Hopi children in the United States, they found
greater left hemisphere lateralization for English, the second language. They
interpret their data as being consistent with the hypothesis that the language itself
may be responsible for their results, with Hopi directing the performer's attention
more to the perceptual field (encouraging more right hemisphere use)
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