Spatial Memory In Amnesia: Evidence from Korsakoff Patients

Abstract

Two experiments are reported which investigated a hypothesised disproportionate deficit in amnesic spatial memory. Korsakoff amnesic memory for the locations of objects or words placed on a grid was compared to control memory which had been attenuated by longer delays before testing. The effects of incidental versus intentional encoding of the locations were compared. No significant evidence of a disproportionate spatial memory deficit in Korsakoff amnesia was found, intentional instructions did not improve Korsakoff amnesic spatial memory scores, and there was no significant evidence of a trade-off of item memo and location memory specific to the Korsakoff amnesic group. Rather, intentional instructions significantly reduced item memory in both Korsakoff amnesics and normal controls while having no effect on spatial memory. When location was scored by lenient criteria, there was no significant difference between groups for this measure nor for recall and recognition memory for these items. Thus Korsakoff amnesic memory was very similar to that of control memory attenuated by longer delays before testing. The Korsakoff amnesic subjects' memory therefore differed quantitatively rather than qualitatively from that of control subjects' memory.