Hemispheric asymmetries in a signal detection task.
Reaction time and signal detection performance were measured during a 78-min. vigilance task. 12 right-handed male subjects served in two experimental sessions. Subjects focused on a central fixation point and responded to signals presented at unpredictable times in one of three locations: 2.5 degrees to right of central fixation, central, and 2.5 degrees to the left of center. Subjects decided whether to press a response key with either the left or right hand with each presentation. Over-all vigilance performance (signal detections and response time) was similar for left and right visual-field presentations. Evidence from reaction times indicated that responses controlled by the left hemisphere were faster to a verbal stimulus (T) while reactions controlled by the right hemisphere were faster to an apparent non-verbal stimulus, an inverted T.
D000328:Adult; D001288:Attention; D004193:Discrimination Learning; D004292:Dominance, Cerebral; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008875:Middle Aged; D010364:Pattern Recognition, Visual; D011930:Reaction Time; D014794:Visual Fields; D014796:Visual Perception