Attentional modulation of perceptual organisation in schizophrenia.
BACKGROUND
Previous studies indicated impaired perceptual organisation in schizophrenia. This study investigated lateral connection and attentional modulation in early visual cortex of schizophrenia patients.


METHODS
Contrast threshold was measured for a central Gabor patch, flanked with orthogonal and collinear Gabor patches. In the attended condition, participants performed a concurrent vernier task by determining the spatial offset of the flankers.


RESULTS
The controls (n=25) had lower contrast thresholds in the collinear condition than in the orthogonal condition, whereas the schizophrenia patients (n=43) did not benefit from the presence of collinear flankers. This deficit was not ameliorated by attentional modulation. Antipsychotic medication did not affect the performance.


CONCLUSIONS
These results suggest that lateral connections are impaired in early visual cortex of schizophrenia patients. This deficit cannot be restored by top-down attentional modulation of target-flanker interactions.
Semmelweis University, Department of Psychiatry and Psychotherapy, Budapest, Hungary. keriszabolcs@psych.sote.hu
Szabolcs
S
Kéri
Oguz
O
Kelemen
György
G
Benedek
D000328:Adult; D000704:Analysis of Variance; D014150:Antipsychotic Agents / Q000494:pharmacology; D001288:Attention / Q000502:physiology*; D003627:Data Interpretation, Statistical; D004493:Education; D005260:Female; D006801:Humans; D007360:Intelligence; D008297:Male; D010775:Photic Stimulation; D012559:Schizophrenia / Q000145:classification; D012565:Schizophrenic Psychology; D014793:Visual Cortex / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*
D014150:Antipsychotic Agents