Serial reaction time as a function of the nature of repeated events

Past research into the phenomenon of reduced latency to repeated events in serial reaction time tasks resulted in attempts to partition reaction time into components attributable to separate cognitive processes. These attempts focused on many-to-one condensing paradigms, which permitted direct assessment of the effect of response-only repetitions but not stimulus-only repetitions. The three experiments reported in the present study used a technique designed to overcome this limitation. It was found that repetition of only the symbolic content of the total stimulus-response event was a sufficient condition for a reduced response latency and that response-only repetitions tended to be facilitative only when stimulus-response relations were compatible. These and related findings were discussed with respect to their bearing on contemporary issues concerning the analysis of cognitive operations into separable and additive components.