title: Memory distortion in Alzheimer's disease: deficient monitoring of short- and long-term memory.
abstract: OBJECTIVE
  This study measured distortions of memory during short-term memory (STM) and long-term memory (LTM) versions of a semantically associated word list learning paradigm. Performance of patients with mild-to-moderate Alzheimer's disease (AD; MMSE ≥16) was compared with performance of age-matched, healthy older adult participants.
  
  
  METHODS
  In a STM version of the Deese-Roediger-McDermott (DRM) task, participants viewed four-word lists and were prompted for recall after a brief interval. The LTM task tested recall memory for 12-word lists.
  
  
  RESULTS
  Compared with the healthy group, the AD participants show greater impairment on the LTM task than on the STM task, although veridical recall is significantly reduced on both tasks. Furthermore, on both memory tasks, (1) participants with AD generate more nonsemantic intrusions than healthy older adult participants, and (2) semantic intrusion rate, when computed as a proportion of total recall, does not differ between groups. Notably, nonsemantic intrusions are consistently high for AD participants across both STM and LTM despite a marked difference in recall accuracy (65% and 23%, respectively).
  
  
  CONCLUSIONS
  STM impairment with some preserved semantic processing is evident in AD. The extent and variety of intrusions reported by AD participants indicates a breakdown in their ability to monitor and constrain their recall responses, even within seconds of initial learning.
authors: Department of Psychology and Neuroscience, Duke University, 417 Chapel Drive, Box 90086, Durham, NC 27708, USA. km170@duke.edu
authors: Katherine E
authors: KE
authors: MacDuffie
authors: Alexandra S
authors: AS
authors: Atkins
authors: Kristin E
authors: KE
authors: Flegal
authors: Christopher M
authors: CM
authors: Clark
authors: Patricia A
authors: PA
authors: Reuter-Lorenz
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications*; D000704:Analysis of Variance; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis* / Q000209:etiology*; D057567:Memory, Long-Term / Q000502:physiology*; D008570:Memory, Short-Term / Q000502:physiology*; D009483:Neuropsychological Tests; D012660:Semantics