TY - JOUR
T1 - Event-related potential repetition effect in Alzheimer's patients
T2 - Multiple repetition priming with pictures
AU - Kazmerski, V. A.
AU - Friedman, D.
AU - Hewitt, S.
N1 - Funding Information:
A progressive memory impairment is the hall-mark symptom of patients diagnosed with probable Alzheimer’s disease (PAD). This deficit is noted on direct or explicit tests of memory, in which the patients are asked to recall or recognize previously stored information (see Carle-simo & Oscar-Berman, 1992, for a review). The performance of PAD patients on indirect or im-plicit tests of memory is less consistent. PAD subjects have shown normal priming on perceptual-identification tasks, in which previously presented words or pseudowords are identified at shorter exposure times than at their initial presentation (Keane, Gabrieli, Fennema, Growdon, & Corkin, 1991; Keane, Gabrieli, Growdon, & Corkin, 1994). Their performance was also intact during lexical-decision tasks, in which they showed faster reaction times (RTs, i.e., facilitation) to repeated than to new words (Mosco-vitch, 1982; Ober & Shenaut, 1988). However, on tests of word-stem completion, the data are inconclusive, and may reflect the type of processing, either perceptual or conceptual, that is required. Intact stem-completion priming was * This research was supported by Grant AGO9988 from the National Institute of Aging to David Friedman; David Friedman is supported by Research Scientist Development Award K02-MH005 10 from the National Institute of Mental Health. We gratefully acknowledge the assistance of Charles L. Brown I11 for computer programming, and the staff of the Alzheimer Disease Research Center, including Yaakov Stern, Mary Sano, and Karen Marder for their assistance in recruiting Alzheimer’s patients. We also thank Elizabeth Squires-Wheeler and Donald Ross for statistical advice.Correspondence concerning this article should be addressed to: Victoria KaLmerski, Division of Humanities and Social Sciences, Pennsylvania State University, The Behrend College, Station Road, Erie, Pennsylvania 16563-1501, USA. Accepted for publication: August 2, 1995.
PY - 1995
Y1 - 1995
N2 - The most notable symptom in probable Alzheimer's disease (PAD) is a profound deficit on direct or explicit memory tasks. In many cases these same patients show performance similar to normal controls on indirect or implicit memory tasks. During indirect testing, recent studies have shown that many PAD subjects have an intact event-related potential (ERP) repetition effect, which is thought to index indirect memory functioning. The present study was designed to test the effect of multiple repetitions on the ERPs of PAD patients. ERPs were recorded from 8 subjects with PAD, 8 elderly and 16 young healthy controls. Subjects were asked to make speeded but accurate choice responses to infrequently occurring animal pictures and frequently occurring nonanimal pictures. Stimuli were presented in four sets of three blocks of trials. Half of the nonanimal items from the first block of each set were repeated in the subsequent two blocks of trials along with new or foil nonanimal pictures, resulting in three presentations of these stimuli. For the ERPs, all three groups of subjects showed activity that was more positive to old than to new items, with no additional enhancement to the third presentation. The ERP enhancement to repeated items was associated with reaction time (RT) facilitation which, in contrast to the ERPs, increased with a third presentation in the two older groups, but not in the young group. These results suggest that ERP and RT repetition priming effects are relatively intact in subjects who are aging normally and in those with a diagnosis of 'mild' Alzheimer's disease.
AB - The most notable symptom in probable Alzheimer's disease (PAD) is a profound deficit on direct or explicit memory tasks. In many cases these same patients show performance similar to normal controls on indirect or implicit memory tasks. During indirect testing, recent studies have shown that many PAD subjects have an intact event-related potential (ERP) repetition effect, which is thought to index indirect memory functioning. The present study was designed to test the effect of multiple repetitions on the ERPs of PAD patients. ERPs were recorded from 8 subjects with PAD, 8 elderly and 16 young healthy controls. Subjects were asked to make speeded but accurate choice responses to infrequently occurring animal pictures and frequently occurring nonanimal pictures. Stimuli were presented in four sets of three blocks of trials. Half of the nonanimal items from the first block of each set were repeated in the subsequent two blocks of trials along with new or foil nonanimal pictures, resulting in three presentations of these stimuli. For the ERPs, all three groups of subjects showed activity that was more positive to old than to new items, with no additional enhancement to the third presentation. The ERP enhancement to repeated items was associated with reaction time (RT) facilitation which, in contrast to the ERPs, increased with a third presentation in the two older groups, but not in the young group. These results suggest that ERP and RT repetition priming effects are relatively intact in subjects who are aging normally and in those with a diagnosis of 'mild' Alzheimer's disease.
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M3 - Article
AN - SCOPUS:0029623117
SN - 0928-9917
VL - 2
SP - 169
EP - 191
JO - Aging and Cognition
JF - Aging and Cognition
IS - 3
ER -
