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Abstract:
Abstract: Children with specific language impairment (SLI)
have deficits in processing brief auditory and grammatical
information. These deficits have been related to deviant anatomical
and functional asymmetry of peri-sylvian cortex and to slowed
processing in auditory cortex. Event-related potentials (ERPs) were
recorded from 31 scalp sites to ìtheî in
auditorally-presented story and nonsense contexts in children with
typical language development (TLD) and SLI. Because this morpheme
is both brief in duration and serves a grammatical function, we
predicted that SLI children would show a deviant ERP topography
and/or time-course in processing ìthe". Children in both
groups showed similar patterns of processing up to approximately
200 ms following the onset of ìtheî. By 220 ms, five
of six SLI children showed suppressed activity indexing the
processing of ìtheî at the left temporal site and a
striking asymmetry between the left and right temporal sites across
all contexts. In general, TLD children's responses showed symmetry
or left-greater-than-right activity. Scalp current density maps
suggest that the source of these generators is the surface of
lateral temporal cortex. The cortical location and relative
lateness of this activity suggests that a deficit in higher-order
auditory processing underlies this language impairment.
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