The lateralized readiness potential and P300 of stimulus-set switching.

The present study aimed at investigating whether stimulus-set switching involves the same stages of information processing as response-set switching. A pair-wise task switching paradigm in which the trial sequences comprised only two tasks was used. The effect of preparation was manipulated so that the participants performed only the repeat trials in some blocks and only the switch trials in other blocks, or both the repeat and switch trials were randomly mixed within a single block. P300 peak latency and stimulus- and response-locked lateralized readiness potential intervals were used to indicate the processing stage of stimulus identification, response selection and motor execution, respectively. The results demonstrated that the stimulus-set switching involves stages of information processing following stimulus identification and before motor execution.