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Abstract:
Abstract: Rediscovery of the cerebellum's role in cognition
has led to an interest in the effects of cerebellar abnormalities
on thought processes. Consequently, cerebellar atrophy has been
linked to both symptomatology and cognitive deficits in
schizophrenia. This study addressed the possibility that linguistic
processing problems in schizophrenia reflect a disrupted neural
pathway that includes the cerebellum. The cerebellum is
anatomically and functionally linked to the frontal cortex, and
coactivation of the frontal cortex with the cerebellum is commonly
observed in verb generation tasks. While generating verbs related
to nouns in the context of competing responses (i.e., high
selection demands) involves the left inferior frontal gyrus
(Thompson-Schill, 1997), basic search strategies have been
associated with the cerebellum (Desmond, 1998). We assessed
strategic search and selection of information from semantic memory
using a verb generation task with high versus low selection
demands. We reasoned that deficits specific to high selection items
would reflect frontal impairments, whereas increased errors in both
high and low selection items would indicate pathology of a wider
neural network. Relative to healthy controls, patients did not show
a selective impairment for high selection items but did produce a
greater number of retrieval errors overall. Generalized impairment
on this task indicated a fundamental disruption in search
strategies, suggesting a dysfunction in frontocerebellar circuitry
in schizophrenia.
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