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Abstract:
Abstract: A crosslinguistic (Chinese, English) PET (positron
emission tomography) study investigated the influence of linguistic
experience on the perception of segmental (consonants, vowels) and
suprasegmental (tones) information. Subjects (10 per group) were
presented binaurally with lists consisting of five Chinese
monosyllabic morphemes or low-pass filtered versions of the same
stimuli, and asked to make same-different judgements of the first
and last items. PET scans were acquired for five tasks presented
twice: one passive listening (pitch); and four active (consonant,
vowel, tone, pitch). Significant regional changes in blood flow
were identified from comparisons of group-averaged images of active
tasks relative to passive pitch. Activation in Chinese listeners
was found in the left premotor cortex on all four active tasks, in
the left pars opercularis on the consonant, vowel, and tone tasks,
and in the left pars triangularis on the consonant and vowel tasks.
Activation in English listeners was found in the left frontal lobe
(premotor cortex/pars opercularis) on the vowel task only, but in
the right frontal lobe on the pitch task. Findings suggest that
functional circuits engaged in speech perception depend on
linguistic experience, all linguistic information signaled by
prosodic cues engages left hemisphere mechanisms, and storage and
executive processes of verbal working memory implicated in
phonological processing are mediated in discrete regions of the
left frontal lobe.
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