EFFECTS OF FOREPERIOD AND TIME ON TASK ON REACTION-TIME AND MOVEMENT TIME

The study was undertaken to investigate the effects of foreperiod (range 0.5 to 5.0 sec.) and 80 min. time on task (TOT) on reaction time (RT) and three subsequent fractions of movement time (MT) in a visual reaction-time experiment. Main effects of foreperiod and TOT, and an interaction between them appeared on RT. During the first 40 min. TOT, the most rapid RTs were observed at the foreperiods exceeding 1.5 sec., while after 40 min. TOT an increment in RT also emerged at the 5-sec. foreperiod. The interaction indicates that some kind of time-dependent fatigue affects ability to maintain preparatory set mainly with long foreperiods. A main effect of foreperiod was observed on all the three fractions of MT; the measurements lengthened with prolonged foreperiods, indicating that onset of foreperiod generates a general preparedness in the motor system. TOT did not affect MT. The study indicates that temporal factors affect the perceptual component of simple human performance more than the motor components.