Repetition effect and short-term memory.

2 experiments are reported which attempted to determine the basis of the "repetition effect," i.e., the observed shorter reaction time (RT) for repeated events than for nonrepeated events. The 1st experiment was designed to determine whether the effect was due primarily to peripheral response facilitation, or primarily to more central coding effects. By employing a condensing task in which the same response was made to 2 different stimuli, it was concluded that the effect was not due to peripheral response facilitation, but appeared to be more central in origin. The 2nd experiment tested the hypothesis that the repetition effect resulted from short-term activation of the S-R memory trace. Some support was found for this prediction. It was found that the repetition effect declind with increasing intertrial interval (ITI) over a range in which decline in short-term memory (STM) is typically reported, and that RT for both repeated and nonrepeated events increased with increased ITI, indicating that increased fading of the memory trace occurred in both conditions.