When false recognition is unopposed by true recognition: Gist-based memory distortion in Alzheimer’s disease

The authors examined false recognition of semantic associates in patients with probable Alzheimer's disease (AD), older adults, and young adults using a paradigm that provided rates of false recognition after single and multiple xposures to word lists. Using corrected false recognition scores to control for unrelated false alarms, the authors found that (a) the level of false recognition after a single list exposure was lower in AD patients than in controls; (b) across 5 trials, false recognition i creased in AD patients, decreased in young adults, and showed a fluctuating pattern in older adults; and (c) all groups howed an increase in true recognition over the 5 trials, Analyses uggested that AD patients built up semantic gist across trials, whereas both control groups were able to use increased item-specific recollection and more conservative r sponse criteria to suppress gist-based false alarms. Patients with probable Alzheimer's disease (AD) not only fail to retrieve desired information but also suffer from distortions of memory (Ftrstl et al., 1994). These memory distortions may impair the ability of the patient with probable AD to live independently (Borson & Raskind