When participants are asked either to repeat the task from the previous trial or switch to the other task, their reaction times are larger for switched than repeated tasks. This "switch cost" has been repeatedly demonstrated in behavioral studies. In this study, event-related potentials (ERPs) were recorded from 12 healthy college students to assess whether this switch cost reflects component processes of preparation and interference. Analyses of ERPs showed that following the cue, there was greater positivity for a switched relative to a repeated trial when the tasks occurred in a fixed-order rather than in a random-order condition. Following the onset of the stimulus-pair, there was greater negativity for switched relative to repeated trials when the task stimulus consisted of both letters and digits but not when it consisted of either a letter or a digit paired with a neutral character. The data provide neurophysiological evidence for the two component processes.
All Science Journal Classification (ASJC) codes
- Experimental and Cognitive Psychology
- Sensory Systems