Age-related Neural Changes during Memory Conjunction Errors

Kelly S Giovanello,Elizabeth A Kensinger,Alana T Wong,Daniel L Schacter

doi:10.1162/jocn.2009.21274

Abstract

Human behavioral studies demonstrate that healthy aging is often accompanied by increases in memory distortions or errors. Here we used event-related fMRI to examine the neural basis of age-related memory distortions. We used the memory conjunction error paradigm, a laboratory procedure known to elicit high levels of memory errors. For older adults, right parahippocampal gyrus showed significantly greater activity during false than during accurate retrieval. We observed no regions in which activity was greater during false than during accurate retrieval for young adults. Young adults, however, showed significantly greater activity than old adults during accurate retrieval in right hippocampus. By contrast, older adults demonstrated greater activity than young adults during accurate retrieval in right inferior and middle prefrontal cortex. These data are consistent with the notion that age-related memory conjunction errors arise from dysfunction of hippocampal system mechanisms, rather than impairments in frontally mediated monitoring processes.

Highlights

■ Human behavioral studies demonstrate that healthy aging accurate retrieval for young adults
Neural Regions Associated with Accurate and Distorted Memories in Young Adults
An ANOVA with Re- We assessed regions activated by young adults for accusponse Type as a within-subject factor rate and distorted memories

Summary

Introduction

■ Human behavioral studies demonstrate that healthy aging accurate retrieval for young adults. Older adults demonstrated greater activity than young adults during accurate retrieval in right inferior and middle prefrontal cortex These f data are consistent with the notion that age-related memory conjunction errors arise from dysfunction of hippocampal syso tem mechanisms, rather than impairments in frontally-mediated Pro monitoring processes. Studies of false recognition, where o people incorrectly claim that they have recently encounc tered a novel item or event and express high confidence in these false claims (Underwood, 1965), have revealed strikn ing age-related increases in memory errors (e.g., Dodson U & Schacter, 2002; Tun et al, 1998; Jennings & Jaocby, 1997; string”—in which one part is studied and one part is novel) In this paradigm, memory failures lead participants to endorse as “old” conjunction and feature lures because such stimuli consist of studied elements— not the specific combination of elements seen at study. Are studied, yet recombined) and feature lures (e.g., “draw- (1996), who conducted two experiments with undergraduate students, older adults, and patients with severe mem-

Results

Discussion

Conclusion