Arousal Effects on Cognition: New Strategy Which Isolates Movement and Heart Rate Effects Inherent in Physical Work

Most experiments which have sought to determine the effects of arousal, exercise and/or physical work on psychomotor performance have been tainted by methodological problems. This paper presents a strategy that was developed to overcome one methodological shortcoming inherent in many such studies: the confounding of movement and heart rate. The technique involves administering mental tests during both movement and non-movement intervals, at pre-selected exercise states. Results of a validation experiment, in which 11 subjects performed numerous psychomotor tasks with and without movement at four work intensities (rest, 30% VO ₂max, 60% VO ₂max, and post-exercise) on two testing days indicate that this method was sufficiently sensitive to identify previously undetected effects, e.g., movement slows index finger tapping rate and may impair an individual's ability to stabilize speed-accuracy tradeoff strategies in serial choice reaction time tasks. Inverted-U effects were also found, replicating some previous investigations. The novel strategy detailed herein, which isolates the relative effects of movement and elevated heart rate, appears appropriate for use in studies aimed at quantifying the effects of exercise-induced arousal (via cycle ergometry) on mental performance before, during, and after exercise. This work has implications for improving research methodologies and predicting which sorts of everyday speeded mental tasks will be affected when one is simultaneously engaged in physical work.