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Abstract:
Abstract: The existence of separate pathways for visual
object and spatial processing is well established (Ungerleider
& Mishkin, 1982). These findings coupled with our previous
research on priming deficits in schizophrenia patients (Salo et al,
1996), motivated us to compare inhibitory and facilitatory priming
effects for spatial (location) and non-spatial (features and
objects) stimuli in schizophrenia patients. Priming is an implicit
measure of previously experienced objects or events on subsequent
processing and can be either inhibitory (i.e. negative priming), or
facilitatory (i.e. positive priming). We compared the time course
of object versus location priming in 16 hospitalized schizophrenia
patients compared to matched controls. The spatial and object tasks
both employed 2-letter displays. Results showed that while spatial
inhibition (i.e. negative priming) decayed across time in the
patients with schizophrenia, inhibition for features and objects
remained robust and even increased at long time delays compared to
controls. Differences in facilitatory priming also emerged between
the groups and differed as a function of task demands. These
results suggest a dissociation of implicit processing for spatial
and non-spatial information consistent with processing of domain
specific information by separate cortical regions on more explicit
tasks (Wilson et al., 1994).
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