title: Process dissociation analyses of memory changes in healthy aging, preclinical, and very mild Alzheimer disease: Evidence for isolated recollection deficits.
abstract: OBJECTIVE
  Recollection and familiarity are independent processes that contribute to memory performance. Recollection is dependent on attentional control, which has been shown to be disrupted in early stage Alzheimer's disease (AD), whereas familiarity is independent of attention. The present longitudinal study examines the sensitivity of recollection estimates based on Jacoby's (1991) process dissociation procedure to AD-related biomarkers in a large sample of well-characterized cognitively normal middle-aged and older adults (N = 519) and the extent to which recollection discriminates these individuals from individuals with very mild symptomatic AD (N = 64).
  
  
  METHODS
  Participants studied word pairs (e.g., knee bone), then completed a primed, explicit, cued fragment-completion memory task (e.g., knee b_n_). Primes were either congruent with the correct response (e.g., bone), incongruent (e.g., bend), or neutral (e.g., &&&). This design allowed for the estimation of independent contributions of recollection and familiarity processes, using the process dissociation procedure.
  
  
  RESULTS
  Recollection, but not familiarity, was impaired in healthy aging and in very mild AD. Recollection discriminated cognitively normal individuals from the earliest detectable stage of symptomatic AD above and beyond standard psychometric tests. In cognitively normal individuals, baseline CSF measures indicative of AD pathology were related to lower initial recollection and less practice-related improvement in recollection over time. Finally, presence of amyloid plaques, as imaged by PIB-PET, was also related to less improvement in recollection over time.
  
  
  CONCLUSIONS
  These findings suggest that attention-demanding memory processes, such as recollection, may be particularly sensitive to both symptomatic and preclinical AD pathology. (PsycINFO Database Record
authors.affiliation: Department of Psychological & Brain Sciences, Washington University in St. Louis.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Millar
authors.affiliation: Department of Psychological & Brain Sciences, Washington University in St. Louis.
authors.forename: David A
authors.initials: DA
authors.lastname: Balota
authors.affiliation: Department of Psychology, Rhodes College.
authors.forename: Geoffrey B
authors.initials: GB
authors.lastname: Maddox
authors.affiliation: Department of Psychological & Brain Sciences, Washington University in St. Louis.
authors.forename: Janet M
authors.initials: JM
authors.lastname: Duchek
authors.affiliation: Department of Neurology, Washington University in St. Louis.
authors.forename: Andrew J
authors.identifier: 0000-0002-4317-7282
authors.initials: AJ
authors.lastname: Aschenbrenner
authors.affiliation: Department of Neurology, Washington University in St. Louis.
authors.forename: Anne M
authors.initials: AM
authors.lastname: Fagan
authors.affiliation: The Charles F. and Joanne Knight Alzheimer Disease Research Center, Washington University in St. Louis.
authors.forename: Tammie L S
authors.initials: TLS
authors.lastname: Benzinger
authors.affiliation: The Charles F. and Joanne Knight Alzheimer Disease Research Center, Washington University in St. Louis.
authors.forename: John C
authors.initials: JC
authors.lastname: Morris
mesh_terms: D000368:Aged; D000375:Aging / Q000523:psychology*; D000544:Alzheimer Disease / Q000000981:diagnostic imaging / Q000235:genetics / Q000523:psychology*; D001057:Apolipoproteins E / Q000134:cerebrospinal fluid / Q000235:genetics; D060825:Cognitive Dysfunction / Q000000981:diagnostic imaging / Q000523:psychology; D005260:Female; D000073656:Healthy Aging; D064368:Healthy Volunteers; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008569:Memory Disorders / Q000000981:diagnostic imaging / Q000523:psychology*; D011939:Mental Recall; D008875:Middle Aged; D009483:Neuropsychological Tests; D058225:Plaque, Amyloid / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography
chemical_list: D001057:Apolipoproteins E