Arousal and Task Performance: The Ubiquitous U-Curve,

It is suggested that arousal is a combination of several relatively independent, imperfectly coupled mechanisms. This view is supported by the extensive literature on the dissociation of the electrocortical, autonomic and behavioural aspects of the arousal paradigm. In the case of electrocortical arousal an inverted U-curve can be demonstrated for tasks involving competing mechanisms e.g. correct detectionfalse positives. The nature of this relationship is that arousal level total for optimum performance is greater for more difficult discriminations. This apparent contradiction of the Yerkes-Dodson Law is explained in terms of the fear-induced drive peculiar to the experimental situation causing a high level of internal task-related arousal. Thus, measured incentive levels, which provide additional arousal through manipulation of the payoff matrix, may be seen to decrease as discriminations become more difficult. Author