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 execution of a psychomotor task were studied to test the applicability of the neuromotor noise concept (Van Gemmert and Van Galen, 1997) as an explanation of stress effects. Central to this notion is that both physical stress and mental load raise neuromotor noise levels in the human information processing system. It is proposed that increased levels of neuromotor noise lead to decreased processing times during task preparation (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 (biomechanical filtering effect). To test these predictions, an experiment was conducted in which two types of auditory stressors, physical stress and mental load, were manipulated across the stages of preparation, initiation, and execution of a graphical aiming task. The results confirmed the notion that the neuromotor noise concept is a tenable approach to explain the effects of stress on human performance.