Simple reaction times to lateralized visual stimuli in a case of callosal agenesis.
Simple reaction times (RTs) of a young acallosal woman were measured using three different intensity levels of the visual stimulus. It was found that "'crossed" stimulus/hand combinations yielded finger RTs about 20 msec longer, on average, than "uncrossed" combinations. In addition, an inverse relation was found between stimulus intensity and the magnitude of this crossed/uncrossed difference in RT. It was also found that vocal RTs displayed a large advantage (18 msec) for right visual-field stimulation. It is suggested that the stimulus information in crossed finger reactions must cross the midline through visually-coded neurones in the acallosal brain.
D000328:Adult; D061085:Agenesis of Corpus Callosum; D003337:Corpus Callosum / Q000502:physiology*; D004193:Discrimination Learning / Q000502:physiology; D004292:Dominance, Cerebral / Q000502:physiology*; D005260:Female; D006801:Humans; D009048:Motor Skills / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D013477:Superior Colliculi / Q000502:physiology; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission; D014795:Visual Pathways / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*