Item recognition is less impaired than recall and associative recognition in a patient with selective hippocampal damage.

ABSTRACT

This article explores the recall, item recognition, and associative recognition memory of patient B.E., whose pattern of retrograde amnesia was reported by Kapur and Brooks (1999; Hippocampus 91-8). Structural magnetic resonance imaging (MRI) has shown that B.E. has bilateral damage restricted to the hippocampus. The structural damage he had sustained was accompanied by bilateral hypoperfusion of the temporal lobe, revealed by positron emission tomography (PET), and which single photon emission computed tomography (SPECT) suggested was greater in the left than the right temporal lobe. B.E. showed a global anterograde amnesia for verbal material, but he displayed some sparing of nonverbal item recognition relative to nonverbal recall and associative recognition. His performance on an item recognition task that used the remember/know procedure and another that involved repetition of the test phase, to reduce the difference between the familiarity of the targets and foils, suggested that his relatively spared nonverbal item recognition may have been mainly supported by familiarity. This finding is consistent with the view that the anterior temporal lobe, including the perirhinal cortex, can support familiarity-based memory judgments (Brown and Bashir, 2002; Philos Trans R Soc Lond B 3571083-1095). B.E.'s data also highlight the importance of functional as well as structural scan information for interpreting the pattern of memory deficits shown by patients with selective hippocampal structural lesions.