Switch-specific and general preparation map onto different ERP components in a task-switching paradigm

We examined whether the cue-locked centroparietal positivity is associated with switch-specific or general preparation processes. If this positivity (300-400 ms) indexes switch-specific preparation, faster switch trials associated with smaller RT switch cost should have a larger positivity as compared to slower switch trials, but no such association should be evident for repeat trials. We extracted ERP waveforms corresponding to semi-deciles of each participant's RT distribution (i.e., fastest to slowest 5% of trials) for switch and repeat conditions. Consistent with a switch-specific preparation process, centroparietal positivity amplitude was linked to slower RT and larger RT switch cost for switch but not repeat trials. A later pre-target negativity (500-600 ms) was inversely correlated with RT for both switch and repeat trials, consistent with a general anticipatory preparation processes.