Cross-modal matching performance in amnesia.

Abstract

A recent neuropsychological study of patients with postencephalitic amnesia raised the possibility that limbic regions within the medial temporal lobe might be important for forming cross-modal associations. The present study evaluated cross-modal matching in amnesic patients with damage to the hippocampal formation or the diencephalon. The patients with hippocampal formation damage were fully intact at cross-modal matching (both tactile to visual and visual to tactile). Two additional (non-Korsakoff's) patients with diencephalic amnesia also performed normally at cross-modal matching. Finally, patients with Korsakoff's syndrome did not exhibit a cross-modal deficit, but they did perform poorly in some task conditions— specifically, when a stimulus examined factually had to be matched to a visual stimulus. The results indicate that severe memory impairment can occur without affecting cross-modal performance.