Neuroscience 2005 Abstract
| Presentation Number: | 643.22 |
|---|---|
| Abstract Title: | Semantic priming in schizophrenia: a magnetoencephalography study. |
| Authors: |
Froud, K.*1
; Levy, D.2
; Marantz, A.3
; Titone, D.4
1Department of Biobehavioral Sciences, Teachers Col., Columbia Univ., New York, NY 2MA, 525 West 120th St, 10027, 3USA, 525 West 120th St, 10027, 4Mailman Research Center, 525 West 120th St, 10027, |
| Primary Theme and Topics |
Cognition and Behavior - Human Cognition, Behavior, and Anatomy -- Language |
| Session: |
643. Language III Poster |
| Presentation Time: | Tuesday, November 15, 2005 9:00 AM-10:00 AM |
| Location: | Washington Convention Center - Hall A-C, Board # FF28 |
| Keywords: | LANGUAGE, BRAIN IMAGING, M350, LEXICAL ACCESS |
Semantic priming in schizophrenia is of interest because semantic memory abnormalities may play a role in numerous cognitive deficits apparent in this population (especially language processing). Behavioral investigations of semantic priming in schizophrenics have yielded mixed results, however; and brain imaging experiments have typically concentrated on sensory processes in schizophrenic brains, including preattentional auditory processing, sensory gating & correlates of sensory hallucination.
We present preliminary results from a magnetoencephalography study of semantic priming in six schizophrenic adults, using a cross-modal lexical decision paradigm. Behavioral results showed normal effects of prime relatedness on reaction times, with priming for words preceded by semantically related items, and inhibition for words preceded by unrelated items. Brain data were collected at 1kHz from a 156-channel axial gradiometer system, and subjected to standard noise-reduction and averaging techniques, before being interrogated for components indexing lexical access, in particular the M350. Schizophrenic individuals demonstrated a range of abnormalities in the M350 field distribution and time window compared to controls, including unusual dissociations between conditions and unusual component properties (e.g. unexpectedly high signal amplitude, anomalous field distributions). We interpret the dissociation between normal behavioral responses to the semantic priming paradigm and extreme (and variable) abnormality in the brain responses to the same task to suggest that semantic knowledge is available in this population, but the neural processes which mediate access to this knowledge are impaired.
We present preliminary results from a magnetoencephalography study of semantic priming in six schizophrenic adults, using a cross-modal lexical decision paradigm. Behavioral results showed normal effects of prime relatedness on reaction times, with priming for words preceded by semantically related items, and inhibition for words preceded by unrelated items. Brain data were collected at 1kHz from a 156-channel axial gradiometer system, and subjected to standard noise-reduction and averaging techniques, before being interrogated for components indexing lexical access, in particular the M350. Schizophrenic individuals demonstrated a range of abnormalities in the M350 field distribution and time window compared to controls, including unusual dissociations between conditions and unusual component properties (e.g. unexpectedly high signal amplitude, anomalous field distributions). We interpret the dissociation between normal behavioral responses to the semantic priming paradigm and extreme (and variable) abnormality in the brain responses to the same task to suggest that semantic knowledge is available in this population, but the neural processes which mediate access to this knowledge are impaired.
Supported by NARSAD
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2005 Neuroscience Meeting Planner. Washington, DC: Society for Neuroscience, 2005. Online.
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