The reaction time experiment was extended by requiring patients with unilateral hemispheric disease to respond differentially to one of one, two, three, or four stimuli. Evaluation was based on the performance of control patients without cerebral disease. Reaction time was found to be an increasing function of the complexity of the task in all groups. While both groups of brain-damaged patients were slower than control patients, under all conditions, the performance of those with unilateral right hemisphere disease paralleled that of controls. The patients with left hemisphere disease, however, showed a more marked retardation in speed of response as the task grew more complex. The results suggest patients with disease of the left hemisphere show relatively greater impairment in speed of decision making in situations of increased complexity than do patients with right hemisphere disease.
Henry L. Dee, Maurice W. Van Allen. Speed of Decision-Making Processes in Patients With Unilateral Cerebral Disease. Arch Neurol. 1973;28(3):163–166. doi:10.1001/archneur.1973.00490210043004