Memory for drawings in locations: Spatial source memory and event-related potentials

Event-related potentials (ERPs) were recorded during recognition tasks for line drawings (items) or for both drawings and their spatial locations (sou rces). Recognized drawings elicited more positive ERPs than new drawings. I ndependent of accuracy in the spatial judgment, the old/new effect in the s ource recognition task was larger over the prefrontal scalp, and of longer temporal duration than in the item recognition task, suggesting that the so urce memory task engaged a qualitatively distinct memory process. More post erior scalp sites were sensitive to the accuracy of the source judgment, bu t this effect was delayed relative to the difference between studied and un studied drawings, suggesting that source memory processes are completed aft er item recognition. Similarities and differences between spatial source me mory and memory for conjunctions of other stimulus attributes are discussed , together with the role of prefrontal cortex in memory.