Material-specific neural correlates of memory retrieval.

It is well established that the neural activity engaged during memory retrieval varies with the kinds of information that are recovered. Less well established is whether this activity reflects online recovery of information, or processes operating downstream of successful recovery. We used event-related potentials (ERPs) to adjudicate between these alternatives, emphasizing that an online recovery account would be supported if material-specific indices of successful retrieval occurred no later than a material-independent index of recollection, the left-parietal ERP old/new effect. A contrast between ERP correlates of successful memory retrieval for words and for faces revealed material-specific neural activity that onset as early as the left-parietal old/new effect. These findings suggest that the material-specific neural activity indexes the online recovery of encoded information.