The interhemispheric functional organization on human visuo-spatial perception.
To investigate the number of correct responses (NCR), the reaction time (RT) and the event-related potentials (ERPs), the visuo-spatial perception of geometric figures in conditions of backward masking was studied in healthy subjects and patients with chronic alcoholism. The performance of a visuo-spatial task of mentally constructing geometric figures was found to be achieved better if a figure-standard could be formed from the presented fragments. The NCR was significantly lower and the RT longer in patients than in healthy subjects. During the solution of this task in controls the RT was shorter if the stimuli were presented in the left visual field. No interhemispheric differences were observed in alcoholics. The late components of ERPs N200 and P300 occurred with a longer latency and lesser amplitudes in patients than in normal controls. Smaller ERP amplitudes were observed in the right hemisphere. The findings support the view that in chronic alcoholism the hemispheric interaction is disturbed due to predominant deficiency of the visuo-spatial function in the right hemisphere.
Tsagareli
M G
MG
Pathophysiology Laboratory, Serbsky Research Institute of General and Forensic Psychiatry, Moscow, Russia.
D000328:Adult; D000437:Alcoholism / Q000523:psychology; D005074:Evoked Potentials, Visual / Q000502:physiology; D005556:Form Perception / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D014785:Vision, Ocular / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology