Interaction of task difficulty, activation, and work load

The performance of 25 subjects in three reaction tasks of different complexity was compared at different activation levels induced by five different work loads on a bicycle ergometer. Heart rate and blood pressure were used as indexes of activation. The results were in agreement with the Yerkes-Dodson law in that the optimal physiological activation level for rapid performance varied with the degree of task difficulty, relatively lower activation being more favorable the more difficult the task.