Abstract

Movement complexity, method of foreperiod presentation (blocked or random), and foreperiod duration have been shown to affect response latency. Previous studies have examined the complexity effect (Henry and Rogers, 1960) and foreperiod effects (Posner and Keele, 1972) independently. However, the present study evaluated whether these processes were additive or interactive in their influences on response latencies. The two experiments in this study used a simple reaction-time (RT) paradigm. In Experiment 1, foreperiod presentation and duration were shown to have an interactive effect on RT for discrete limb movements to a single target. For block presentations of fore-periods, RTs were an increasing function of foreperiod duration whereas for random presentations, RTs were a decreasing function of foreperiod duration. In Experiment 2, the movement complexity effect was found to be independent of the foreperiod effects. That is, the same pattern of RTs for the foreperiod effects was found for both the simple and complex movements. Thus, the complexity effect and the foreperiod effects have an additive relationship, suggesting that each is influencing a separate aspect of response preparation. Verf.-Referat