Effects of task difficulty and invested mental effort on peripheral vasoconstriction

We conducted four experiments to test the effects of task difficulty and invested mental effort on peripheral vasoconstriction. Finger pulse wave amplitude was recorded from male undergraduatestudents by means of a newly developed finger plethysmographthat measures peripheral arterial tone (PAT) during both rest and cognitive performance. The difference in PAT amplitude between rest and task periods suggests that PAT amplitude reflects changes in sympathetic activity due to task engagement. As the demands of the task increase, PAT amplitude tends to decrease. Our results seem to suggest that peripheral vasoconstriction may be more sensitive to the amount of voluntary effort invested in task performance rather than to the objective task demands.