When more means less: neural activity related to unsuccessful memory encoding.

The neural correlates of memory encoding have been studied by contrasting neural activity elicited by items at the time of learning according to whether they were later remembered or forgotten [1]. Previous studies have focused on regions where neural activity is greater for subsequently remembered items [2-8]. Here, we describe regions where activity is greater for subsequently forgotten items. In two experiments that employed the same incidental learning task, activity in an overlapping set of cortical regions (posterior cingulate, inferior and medial parietal, and dorsolateral prefrontal) was associated with failure on a subsequent memory test.