When true recognition suppresses false recognition: evidence from amnesic patients.

Daniel L Schacter,Carrie Racine,Michael D Anes,Mieke Verfaellie

doi:10.1162/089892998563086

Daniel L Schacter, Carrie Racine + Show 2 more

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https://doi.org/10.1162/089892998563086

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Abstract

False recognition occurs when people mistakenly claim that a novel item is familiar. After studying lists of semantically related words, healthy controls show extraordinarily high levels of false recognition to nonstudied lures that are semantic associates of study list words. In previous experiments, we found that both Korsakoff and non-Korsakoff amnesic patients show reduced levels of false recognition to semantic associates, implying that the medial temporal/diencephalic structures that are damaged in amnesic patients are involved in the encoding and/or retrieval of information that underlies false recognition. These data contrast with earlier results indicating greater false recognition in Korsakoff amnesics than in control subjects. The present experiment tests the hypothesis that greater or lesser false recognition of semantic associates in amnesic patients, relative to normal controls, can be demonstrated by creating conditions that are more or less conducive to allowing true recognition to suppress false recognition. With repeated presentation and testing of lists of semantic associates, control subjects and both Korsakoff and non-Korsakoff amnesics showed increasing levels of true recognition across trials. However, control subjects exhibited decreasing levels of false recognition across trials, whereas Korsakoff amnesic patients showed increases across trials and non-Korsakoff amnesics showed a fluctuating pattern. Consideration of signal detection analyses and differences between the two types of amnesic patients provides insight into how mechanisms of veridical episodic memory can be used to suppress false recognition.

Highlights

Memory is often accurate, it is subject to various kinds of errors and distortions
To account for the sharp contrast between the Cermak et al (1973) results and those of Schacter, Verfaellie, et al (1996) and Schacter, Verfaellie, et al (1997), we suggested that when numerous associates are presented during study, normal controls establish a well-organized representation of the semantic or perceptual gist (Reyna & Brainerd, 1995) of the study list; when this representation is matched by a new theme word, normal controls experience a strong sense of familiarity or recollection that produces a robust false recognition effect
Preliminary analyses revealed no signiacant differences between the two amnesic subgroups for true recognition, so we present statistical analyses of these data collapsed across the two amnesic subgroups

Summary

Introduction

Memory is often accurate, it is subject to various kinds of errors and distortions (for recent reviews, see Johnson, Hashtroudi, & Lindsay, 1993; Roediger, 1996; Schacter, 1995). During the past several years, there has been growing interest in the brain structures and processes that are related to memory errors and distortions, as explored in experiments with various patient populations (cf Kroll, Knight, Metcalfe, Wolf, & Tulving, 1996; Metcalfe, Funnell, & Gazzaniga, 1995; Moscovitch, 1995; Parkin, Binschaedler, Harsent, & Metzler, 1996; Reinitz, Verfaellie, & Milberg, 1996; Schacter, Curran, Galluccio, Milberg, & Bates, 1996) and in neuroimaging studies (Duzel, Yonelinas, Mangun, Heinze, & Tulving, 1997; Johnson et al., 1997; Schacter, Buckner, Koutstaal, Dale, & Rosen, 1997; Schacter, Reiman, et al, 1996; for review, see Schacter, Norman, & Koutstaal, 1998). After studying lists of semantic associates that all converge on a nonpresented “theme word,” participants frequently claim to remember the nonpresented word (cf. Israel & Schacter, 1997; Mather, Henkel, & Johnson, 1997; Norman & Schacter, 1997; Payne, Elie, Blackwell, & Neuschatz, 1996; Robinson & Roediger, 1997; Roediger & McDermott, 1995)

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