Did I do that? An ERP study of memory for performed and planned actions.

Memory for performed and planned actions was measured on source recognition and source recall tests. Event-related potentials (ERPs) were recorded during the source recognition test to index brain activity during output monitoring. Source identification of performed actions was superior to planned actions and more performed actions were recalled, thereby replicating the enactment effect. Examination of recall errors revealed that more planned than performed actions were omitted. In addition, intrusions and source misattributions were equally likely when recalling planned actions, whereas more misattributions were observed when performed actions were recalled. The ERP data indicated that brain activity elicited by performed actions differed from planned and new actions. Furthermore, activity in the left and right frontal lobes appeared to differ for performed and planned actions indicating that performed actions were evaluated with more heuristic decision processes than both planned and new items. The temporal onset of the frontal ERP differences also suggests that heuristic decision processes begin earlier than systematic processes.