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 9:1-8). 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 357:1083-1095). 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.

Impaired capacity for familiarity after hippocampal damage

“…Other studies have also used the Remember-Know procedure to assess the capacity of recollection and familiarity in memoryimpaired patients with lesions that include the hippocampus (11)(12)(13)(14)(15)(16)(17). Patients typically exhibit a markedly reduced frequency of R responses but only a modest reduction (or no reduction) in the frequency of K responses.…”

“…Participants were instructed to use the entire scale. For words declared old (ratings of [11][12][13][14][15][16][17][18][19][20], participants also judged whether the word was recollected, was familiar, or was a guess, following a Remember-KnowGuess procedure (9,26). The modified instructions emphasized that participants should use the R response only if they could actually describe specific details about the experience of studying the word.…”

“…For words declared old (ratings of [11][12][13][14][15][16][17][18][19][20], participants then judged whether the word was recollected (Remember), was familiar (Know), or was a guess (Guess). Then, to examine the frequency of R and K responses in each group after removing the effect of memory strength, we compared performance for items endorsed with high confidence (ratings of [17][18][19][20].…”

Towards a functional organization of the medial temporal lobe memory system: Role of the parahippocampal and medial entorhinal cortical areas

“…These studies provide striking evidence for selective involvement of the perirhinal cortex in familiarity but not recollection, and for the hippocampus and parahippocampal region in recollection, not familiarity. Several studies have reported that transient hypoxia, which more significantly affects the hippocampus than parahippocampal region, results in disproportional deficits in memory for associations or context compared to item recognition (Mayes et al, 2002;Giovanello et al, 2003;Turriziani et al, 2004;Holdstock et al, 2005). One study that used a receiver operating characteristic (ROC) analysis showed that mildly hypoxic patients exhibited severe deficits in recollection, but normal familiarity (Yonelinas et al, 2002).…”

Recognition memory signals in the macaque hippocampus

“…Studies of developmental as well as adult-onset amnesia have reported cases in which hippocampal damage produced intact recognition memory but impaired episodic memory, or the ability to recollect information pertaining to the specific event during which the stimulus was first encountered (11,12,15,18, but see also 6). The "RememberKnow" procedure has often been used to try to distinguish impairments in simple recognition from deficits in recall (12,15,(19)(20)(21). However, this depends on the assumption that Remember judgments reflect recollection while Know judgments reflect familiarity.…”