When false recognition is unopposed by true recognition: Gist-based memorydistortion in Alzheimer's disease

The authors examined false recognition of semantic associates in patients w ith probable Alzheimer's disease (AD), older adults, and young adults using a paradigm that provided rates of false recognition after single and multi ple exposures to word lists. Using corrected false recognition scores to co ntrol for unrelated false alarms, the authors found that (a) the level of f alse recognition after a single list exposure was lower in AD patients than in controls; (b) across 5 trials, false recognition increased in AD patien ts, decreased in young adults, and showed a fluctuating pattern in older ad ults; and (c) all groups showed an increase in true recognition over the 5 trials. Analyses suggested that AD patients built up semantic gist across t rials, whereas both control groups were able to use increased item-specific recollection and more conservative response criteria to suppress gist-base d false alarms.