PERCEPTUAL AND CONCEPTUAL MEMORY PROCESSES IN GLOBAL AMNESIA

To determine whether global amnesia reflects a selective deficit in conceptual processing, amnesic and control subjects performed 4 memory tasks that varied processing and retrieval requirements. A study-phase modality (auditory/visual) manipulation validated the nature of processing (perceptual and conceptual) engaged by each task. Amnesic patients were impaired on perceptual and conceptual explicit memory tasks (word-fragment and word-associate cued recall) and were intact on perceptual and conceptual implicit memory tasks (word-fragment completion and word association). These results are consistent with the view that limbic-diencephalic structures damaged in amnesia mediate, in part, processes typically engaged during explicit retrieval. The results are inconsistent, however, with the characterization of that deficit as being one of conceptual processing per se.