To understand how task switching affects human performance, there is a need to investigate how it influences the performance of tasks other than those involving bivalent stimulus categorization. The purpose of this study, therefore, was to investigate the effects of task switching on anticipation timing performance, which typically requires participants to track the apparent motion of a light along a series of lamps and press a button when the target lamp is illuminated. Participants were 36 university students who gave informed consent and participated voluntarily. Participants had no prior experience with the task and were naive to the purposes of the study. The switching effects observed in both constant error (CE) and absolute constant error (ACE) confirmed the prediction that switching between tasks resulted in degraded performance compared to conditions that repeated a single task. These findings verified that switching effects occur outside the stimulus categorization tasks used in most previous studies. Although switching effects have been previously attributed to inadequate preparation, either from a lack of time or response uncertainty, it was unlikely these contributed to the present results because of the relatively long intertrial intervals and a predictable schedule used in the alternating condition. Thus, the effects observed in the present study were consistent with the perspective that persisting activation causes interference when switching to a different task. (Contains 3 figures.)