Central and peripheral visual choice-reaction time under conditions of induced cortical hyperthermia

Six right-handed male subjects performed a central and peripheral visual choice-reaction time (RT) task. After two initial practice periods, subjects performed counterbalanced manipulations of control, placebo, and heat conditions. In the heat condition, a helmet selectively raised cortical temperature, measured in the external auditory meatus, by 7 degrees F while the placebo condition utilized the helmet with no external heat applied. Analysis indicated that the elevation of cortical temperature caused an increase in RT and decreased rate of errors. This conservatism in subjects' response under induced cortical hyperthermia is contrasted with previous accounts of visual RT performance under manipulations of whole-body heat stress.