REACTION TIME AND MOVEMENT TIME AS A FUNCTION OF AGE, STIMULUS DURATION, AND TASK DIFFICULTY

Abstract

Abstract This study investigated the effects of age, stimulus duration, and task difficulty on reaction time and movement time. Subjects made a simple guided movement in response to the onset of a stimulus light. Two levels of task difficulty (simple and two-choice reaction) and three durations of the light (50 msec, response terminated, and movement terminated) were used to define six experimental conditions. Forty-eight subjects were used : 24 college sophomores with a median age of 20. and 24 elderly persons with a median age of 75. Older subjects reacted 11 per cent slower and moved 38 per cent slower than young. Choice reactions wore slower than simple reactions. Old subjects, but not young, moved faster in simple trials than in choice. The effect of stimulus duration was not significant. A predicted interaction of stimulus duration and age was also not supported. Proportionately greater slowing of reaction time for old subjects as difficulty increased was observed but failed to reach an acceptable l...