Serial Choice Reaction-time as a Function of Response versus Signal-and-Response Repetition

Abstract

IN serial self-paced choice reaction, reaction times (RTs) to repeated signals, that is, to a signal identical to the immediately preceding one, are shorter than RTs to new signals, that is, to a signal different from the preceding one, provided the time-lag separating the onset of each signal from the end of the previous response is short. This was shown in tasks involving either two signals and two responses^1,2 or four signals and four responses², where repetition of the response was, except for the very rare errors, obtained only through repetition of the signal. The present letter reports a first trial to distinguish the effort of signal repetition, not confounded with that of response repetition, by considering a task where more than one signal is associated with each response. In such a situation, the relationship of a cycle to the preceding cycle can be one of ‘identity’ (same signal), of ‘equivalence’ (different signal but same response) or of ‘difference’ (different response). By comparing RTs on cycles belonging to the first two categories, one could then examine if repetition of the signal has an effect per se.