A re-examination of recognition memory in amnesia: Reply to Roediger and McDermott.

In a previously reported study using the process dissociation procedure, we (M. Verfaellie & J. Treadwell, see record 1993-18420-001) demonstrated that amnesic patients were impaired relative to controls in their recognition of words they had solved as anagrams but performed comparably to controls in their recognition of words they had read. H. L. Roediger and K. B. McDermott (see record 1994-30444-001) suggested that the finding of normal performance in the read condition of our study might have been due to differing false-alarm rates between groups, a finding that would complicate application of the process dissociation procedure. In this reply, we argue that the amnesic patients' normal performance in this condition was not due just to differences in guessing rate and is not inconsistent with findings from standard recognition memory tests. In addition, 2 corrections to the process dissociation procedure discussed by Roediger and McDermott are considered as solutions to the problem of differing false-alarm rates. Applied to our amnesic data, these corrections reinforce our original conclusion that under conditions in which the contribution of recollection is minimal, amnesic patients' performance is normal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Knowledge of New English vocabulary in amnesia: an examination of premorbidly acquired semantic memory

To assess if amnesics have intact remote memory for general semantic information, we examined memory for vocabulary words with known dates of entry into the language between 1955 and 1989. Amnesics of mixed etiology with acute onset performed normally on both a recall and a recognition task. Korsakoff patients, in contrast, were impaired on both tasks and demonstrated a gradient such that their knowledge of words acquired during more recent time periods was worse than that of words acquired during more remote time periods. The improvement in performance associated with recognition testing was larger for Korsakoff patients than for control subjects and correlated significantly with a composite measure of frontal dysfunction. These findings suggest a deficit in the controlled search and retrieval of semantic information in Korsakoff patients. The implications of the differential performance of Korsakoff and mixed etiology amnesics for explanations of temporally graded retrograde amnesia are discussed.     

Comparison of cross-field matching and forced-choice identification in hemispatial neglect.

The ability of patients with neglect to process information in the contralateral field was examined by comparing performance on a cross-field matching and a forced-choice identification task. The matching task required participants to judge whether 2 laterally presented pictures were the same or different. The identification task required selection of 1 of 2 centrally presented pictures that were identical to a lateralized target. As a group, neglect patients performed at chance on the identification task but significantly above chance on the cross-field matching task. However, the dissociation between matching and identification was present only for patients whose identification performance was at chance; patients with above-chance identification performed equally well on both tasks. Mechanisms underlying the matching and identification performance of both patient subgroups are discussed in light of procedural differences between the tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dissociations between familiarity processes in explicit recognition and implicit perceptual memory.

Dual-process theories of recognition posit that a perceptual familiarity process contributes to both explicit recognition and implicit perceptual memory. This putative single familiarity process has been indexed by inclusion–exclusion, remember–know, and repetition priming measures. The present studies examined whether these measures identify a common familiarity process. Familiarity-based explicit recognition (as indexed by the inclusion–exclusion and the independence remember–know procedures) increased with conceptual processing. In contrast, implicit word-identification priming and familiarity-based word-stem completion (as indexed by inclusion–exclusion) increased with study–test perceptual similarity. These dissociations indicate that familiarity-based explicit recognition may be more sensitive to conceptual than to perceptual processing and is functionally distinct from the perceptual familiarity process mediating implicit perceptual memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relationship between recall and recognition in amnesia: Effects of matching recognition between patients with amnesia and controls.

To examine the relationship between recall and recognition memory in amnesia, the authors conducted 2 experiments in which recognition memory was equated between patients with amnesia and control participants. It was then determined whether recall was also similar across groups. In Experiment 1, recognition was equated by providing amnesic patients with additional study exposures; in Experiment 2, recognition was equated by testing controls following a longer delay. These different methods of equating recognition across groups led to divergent results because amnesic patients' recall performance was lower than controls' recall performance in Experiment 1 but not in Experiment 2. These findings are accounted for by considering the differential contribution of recollection and familiarity to the performance of amnesic patients and controls in the 2 experiments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Benefits of immediate repetition versus long study presentation on memory in amnesia.

Objective: This study aimed to resolve discrepant findings in the literature regarding the effects of massed repetition and a single long study presentation on memory in amnesia. Method: Experiment 1 assessed recognition memory in 9 amnesic patients and 18 controls following presentation of a study list that contained items shown for a single short study presentation, a single long study presentation, and three massed repetitions. In Experiment 2, the same encoding conditions were presented in a blocked rather than intermixed format to all participants from Experiment 1. Results: In Experiment 1, control participants showed benefits associated with both types of extended exposure, and massed repetition was more beneficial than long study presentation, F(2, 34) = 14.03, p F F(2, 50) = 4.80, p = .012, partial η2 = .16. Amnesic patients showed significant and equivalent benefit associated with both types of extended exposure, F(2, 16) = 5.58, p = .015, partial η2 = .41, but control participants again benefited more from massed repetition than from long study presentation, F(2, 34) = 23.74, p     

Implicit memory for pictures in amnesia: Role of etiology and priming task.

This study examined the performance of patients with Korsakoff and non-Korsakoff amnesia on tests of picture priming. Both groups showed intact priming on a picture-naming task but impaired priming on a fragment-completion task when fragmented pictures were presented at study. When whole pictures were presented at study, patients with non-Korsakoff amnesia showed intact priming, but Korsakoff patients' priming remained impaired. Both groups performed equally poorly on a picture-recognition task. It is concluded that non-Korsakoff patients show intact picture priming when explicit memory does not contaminate fragment-completion performance. Korsakoff patients, in contrast, show a selective impairment in the perceptual processes that mediate picture-fragment completion priming. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recognizing identical versus similar categorically related common objects: Further evidence for degraded gist representations in amnesia.

Studies have shown lower false recognition of semantically related lure words in patients with global amnesia than in matched controls. This pattern has been interpreted as suggesting that medial temporal and diencephalic structures that are damaged in amnesia and that contribute to veridical memory also contribute to false recognition. It has been argued that whereas controls form and retain a well-organized representation of the semantic gist of studied items, patients with amnesia can retain only a degraded gist representation. However, these studies are subject to an alternative interpretation involving greater source confusions in controls. The authors used a categorized-pictures paradigm to test recognition under conditions in which source confusions were unlikely to occur. Relative to controls, patients with amnesia showed reduced false recognition of categorically related pictorial lures, thereby supporting the notion of degraded gist representations in amnesia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Absence of size congruency effects in amnesic patients' recognition: A failure of perceptually based recollection.

This study examined the status of recollection in amnesia when recollection is supported by perceptual rather than conceptual processes. Two experiments investigated the size congruency effect--the advantage in recognition of patterns presented in the same size, rather than in different sizes--at study and test. In Experiment 1, the authors used a remember-know paradigm in nonamnesic individuals and demonstrated that the size congruency effect was due to enhanced recollection. In Experiment 2, the authors examined whether amnesic patients would show a size congruency effect when their overall level of performance was matched to that of controls. Amnesic patients failed to show a size congruency effect. These findings provide evidence for a disproportionate disruption in recollection compared with familiarity in amnesia, even when recollection is supported by perceptual processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attributions of familiarity in amnesia: Evidence from a fame judgment task.

To evaluate the extent to which amnesic patients can attribute the source of familiarity to its correct source during a fame judgment task, gains in familiarity were placed in opposition to conscious recollection. In the 1st experiment, patients and controls were told specifically that nonfamous names presented just prior to a fame judgment task were not famous; in the 2nd experiment they were told that nonfamous names were in fact famous. Although such instructions produced dramatically different results in the fame judgment performance of normal control Ss, minimal change in attribution of fame occurred for the amnesic Ss. It is concluded that the amnesic Ss were unable to attribute the familiarity of a previously presented name to its correct source because of their inability to recollect a name's prior presentation. Hence, it may be the nature of the memory query rather than the adequacy of a specific memory system that determines whether or not an amnesic patient can access information in memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)