AUDITORY STRESS EFFECTS ON PREPARATION AND EXECUTION OF GRAPHICAL AIMING - A TEST OF THE NEUROMOTOR NOISE CONCEPT

Effects of physical and mental stress, on the preparation and executio n of a psychomotor task were studied to test the applicability of the neuromotor noise concept (Van Gemmert and Van Galen, 1997) as an expla nation of stress effects. Central to this notion is that both physical stress and mental load raise neuromotor noise levels in the human inf ormation processing system. It is proposed that increased levels of ne uromotor noise lead to decreased processing times during task preparat ion (activation effect), decreased or increased reaction times during task initiation, depending on task difficulty (impoverished signal-to- noise effect) and increased limb stiffness during task execution (biom echanical filtering effect). To test these predictions, an experiment was conducted in which two types of auditory stressors, physical stres s and mental load, were manipulated across the stages of preparation, initiation, and execution of a graphical aiming task. The results conf irmed the notion that the neuromotor noise concept is a tenable approa ch to explain the effects of stress on human performance. (C) 1998 Els evier Science B.V.