Generation effects and source memory in healthy older adults and in adults with dementia of the Alzheimer type.

Recognition and source memory were explored in healthy older adults, adults diagnosed with very mild dementia of the Alzheimer type (DAT), and adults diagnosed with mild DAT. Two sentence-completion tasks were used. In Task 1, half of the sentences were completed (clozed) by the participant, and half by the experimenter. In Task 2, half were participant clozed, and half were participant read (already clozed). Recognition of the cloze words and accuracy of categorizing them as participant generated or experimenter generated (Task 1) and participant generated or participant read (Task 2) were measured (source discrimination). Contrary to previous reports, the DAT groups showed the generation effect, that is, better recognition for participant-generated words than experimenter-generated words (Task 1) or read words (Task 2). Source discrimination was disproportionately impaired in the DAT groups. Memory impairment is the hallmark of dementia of the Alzheimer type (DAT; e.g., Portions of these data were presented at the Second Annual Meeting of the Cognitive Neuroscience Society, March 1995, San Francisco, California. This research was supported by National Institute on Aging Grant AG00030. Martha Storandt is gratefully acknowledged for allowing us to include our tasks in her neuropsychological test battery and for providing the psychometric data reported in this article. Special thanks go to Martha Storandt's research team, particularly Emily La Barge, for their help in the data collection. John C. Morris, Director, Washington University Alzheimer's Disease Research Center Clinical Core, is gratefully acknowledged for providing diagnostic and dementia severity ratings. We thank Debra A. Grosse-Fleischman for sharing her materials with us. Special thanks go to Greta Munger for her help with the final figures. Thanks also go to Mark E. Faust and to Marcia K. Johnson for helpful discussions of this project. Correspondence concerning this article should be addressed to Kristi S. Multhaup, who is now at the Department of Psychology, Davidson College, Davidson, North Carolina 28036-1719. Electronic mail may be sent via Internet to [email protected]. priming in their DAT group, Gabrieli et al. argued that repetition priming is composed of perceptual and nonperceptual components that can be dissociated. Therefore, recent neuropsychological studies of memory indicate that thorough examination of different populations' memory performance can reveal important clues regarding the organization of human memory. The goal of the present study is to provide information concerning the nature of the memory impairments associated with DAT. In pursuit of this goal, the present article explores three major issues. The first issue is whether early-stage DAT individuals show the generation effect, which occurs when people better remember information that they had to produce (e.g., producing associates to a word) compared with information that was given to them (e.g., reading words; Generation Effect There are several reports in the literature that suggest that individuals diagnosed with DAT do not show the generation effec

Phonological blocking during picture naming in dementia of the Alzheimer type

Individuals with dementia of the Alzheimer type (DAT; n ϭ 53, ages 55-91), healthy older adults (n ϭ 75, ages 59 -91), and younger adults (n ϭ 24, ages 18 -24) performed a word-primed picturenaming task. Word primes were neutral (ready), semantically or phonologically related, or unrelated to the correct picture name. All groups produced equivalent unrelated-word interference and semantic priming effects in response latencies. However, analysis of errors revealed a DAT-related increase of phonological blocking. The results suggest that picture-naming errors in DAT are due, at least in part, to a breakdown in access to phonological representations of object names as a consequence of reduced inhibitory control over other highly active alternatives