IMPAIRED EARLY VISUAL PROCESSING IN DISORGANIZED SCHIZOPHRENIA

Topographic differences in flash/pattern shift VEP data are evaluated in paranoid (n : 38), disorganized (n :23) and residual (n : 23) schiz ophrenic subtypes and compared to normal controls. Increased early P-1 and a restricted diffusion of the late P-2 responses suggest dopamine rgic over- and cholinergic underactivity in paranoid and residual schi zophrenia. A distinctive pattern N-145 reflects well-preserved attenti onal resources in the paranoid subtype. Latency increase and amplitude decrease of the pattern N-145 concur with abnormal antisaccades docum ented in disorganized behaviour. VEP-data might help differentiate bet ween schizophrenic subtypes.