Disproportionate deficit in associative recognition relative to item recognition in global amnesia

Abstract

In two experiments, we tested the hypothesis that medial temporal lobe (MTL) amnesic patients and, likewise, diencephalic (DNC) amnesic patients evidence a disproportionate deficit in memory for associations in comparison with memory for single items. In Experiment 1, we equated item recognition in amnesic and control participants and found that, under these conditions, associative recognition remained impaired both for MTL patients and for DNC patients. To rule out an alternative interpretation of the results of Experiment 1, in Experiment 2 we compared the performance of amnesic and control participants on a one-item recognition task and a two-item recognition task that required no memory for the association between members of word pairs. In the MTL group, when single-item recognition was equated to that of the controls, two-item nonassociative pair memory was equivalent as well. In the DNC group, nonassociative pair memory was impaired, but this impairment did not fully account for the impairment in associative memory. These findings indicate that memory for novel associations between items is disproportionately impaired in comparison with memory for single items in amnesia.

Working Memory for Conjunctions Relies on the Medial Temporal Lobe

“…Previous findings have provided evidence for the relational processing theory by showing that the MTL is necessary for conjunction memory over long delays (Cermak, 1976;Winocur and Weiskrantz, 1976;Chun and Phelps, 1999;Giovanello et al, 2003) (but see Stark and Squire, 2001). Our work extends the relational processing theory (Cohen and Eichenbaum, 1993;Eichenbaum, 1999) by showing that the MTL is necessary for relational processing at delays as short as 8 s.…”

“…MTL amnesics have profound difficulties in remembering learned word pairs as compared with single words (Cermak, 1976;Winocur and Weiskrantz, 1976;Giovanello et al, 2003;Turriziani et al, 2004). Several neuroimaging studies have reported greater activations in MTL structures during encoding (Henke et al, 1997;Davachi et al, 2003;Kirwan and Stark, 2004;Ranganath et al, 2004) and retrieval (Yonelinas et al, 2001;Giovanello et al, 2004) of the relationship between stimuli as opposed to separate stimuli.…”

Memory Retrieval in Mice and Men

“…Whereas many studies report a disproportionate effect of hippocampal damage on recollection and associative memory relative to familiarity (Huppert and Piercy 1978;VarghaKhadem et al 1997;Holdstock et al 2002;Yonelinas et al 2002;Giovanello et al 2003;Mayes et al 2004;Aggleton et al 2005), other reports find that hippocampal damage impacts familiarity and recollection to a similar extent (Manns and Squire 1999;Stark et al 2002;Manns et al 2003;Cipolotti et al 2006;Wais et al 2006;Jeneson et al 2010;Kirwan et al 2010;Song et al 2011). Interestingly, a patient with significant perirhinal damage that spared the hippocampus showed impaired familiarity and preserved recollection (Bowles et al 2007).…”

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).…”