Event-related potentials (ERPs) were recorded during recognition tasks for spoken words alone (items) or for both words and the voice of the speaker (sources). Neither performance nor ERP measures suggested that voice information was retrieved automatically during the item-recognition task. In both tasks, correctly recognized old words elicited more positive ERPs than new words, beginning around 400 ms poststimulus onset. In the source task only, old words also elicited a focal prefrontal positivity beginning about 700 ms. The prefrontal task effect did not distinguish trials with accurate and inaccurate voice judgments and is interpreted as reflecting the search for voice information in memory. More posterior recording sites were sensitive to the successful recovery of voice or source information. The results indicate that word and voice information were retrieved hierarchically and distinguish retrieval attempt from retrieval success.Everyone has had the experience of remembering a fact without being able to recall how it was learned. Remembering the source of one's knowledge is not always important, but in some cases, it may be critical for one's subsequent actions. If you own a cellular phone, it is important to remember whether the link between such phones and brain tumors was reported in the New England Journal of Medicine or the National Enquirer. Source memory can be broadly defined as memory for the context of a learning episode, encompassing perceptual features (e.g., the voice or face of a speaker who conveyed some information, visual or auditory modality of a word), spatial location, temporal sequence of events, and whether an event was imagined or actually took place (for a review, see Johnson, Hashtroudi, & Lindsay, 1993).A few recent neuropsychological studies have suggested that source memory is dissociable from other forms of memory. In a group of patients with amnesia subsequent to brain damage, Schacter, Harbluk, and McLachlan (1984) found that the level of impairment for remembering trivia facts was uncorrelated with performance in remembering which experimenter conveyed the facts that were recalled. Squire (1987, 1991) reported similar findings in both amnesic patients and those with temporary We are grateful to Ron Ohst for software support and to Sheryl Reminger for assistance with editing stimuli.Correspondence concerning this article should be addressed to Ava J. Senkfor, Department of Psychology, University of Arizona, Tucson, Arizona 85721-0068. Electronic mall may be sent to asenkfor @ rosalind.ucsd.edu. memory impairment following electroconvulsive therapy. Janowsky, Shimamura, and Squire (1989) obtained a particularly clear dissociation between item and source memory in patients who were not generally amnesic. Patients with damage confined to the frontal lobe exhibited normal recall and recognition of trivia facts learned in the laboratory but a disproportionate number of errors of attributing their knowledge to an extraexperimental source. This demonstration that frontal cortex i...