Abnormal premovement brain potentials in schizophrenia.
We assessed scalp-recorded movement related potentials (MRPs) generated prior to voluntary movements in chronic, medicated schizophrenics (n = 9) and age matched normal controls (n = 9). MRPs were recorded in a self-paced button press task in which subjects pressed a button with either their right, left or both thumbs (experimental condition I, II and III respectively). Controls generated a slowly rising readiness potential (RP) at about 1000 ms, a negative shift (NS') at about 450 ms and a motor potential (MP) at about 100 ms prior to movement. The initial MRP components (RP and NS') were reduced in schizophrenics indicating an impairment of the voluntary preparatory process in schizophrenia. Results of the present study indicate a similarity of MRP findings in schizophrenics and reported MRPs (Singh and Knight, 1990) in patients with unilateral lesions of the dorsolateral prefrontal cortex. These findings provide further support for frontal lobe dysfunction in schizophrenia.
Department of Psychology, Northwestern University.
J
J
Singh
R T
RT
Knight
N
N
Rosenlicht
J M
JM
Kotun
D J
DJ
Beckley
D L
DL
Woods
D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use; D001143:Arousal / Q000187:drug effects / Q000502:physiology*; D001288:Attention / Q000187:drug effects / Q000502:physiology*; D001931:Brain Mapping / Q000295:instrumentation; D002540:Cerebral Cortex / Q000187:drug effects / Q000503:physiopathology; D003265:Contingent Negative Variation / Q000502:physiology; D004569:Electroencephalography / Q000295:instrumentation*; D005625:Frontal Lobe / Q000187:drug effects / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011597:Psychomotor Performance / Q000187:drug effects / Q000502:physiology*; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D012559:Schizophrenia / Q000188:drug therapy / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*
D014150:Antipsychotic Agents