title: Assessing the cognitive abilities that differentiate patients with Alzheimer's disease from normals: single and multiple factor models.
abstract: BACKGROUND
  Understanding the structure of cognitive abilities in Alzheimer's disease (AD) has considerable practical and theoretical importance. Some investigators have argued that a single cognitive process underlies the deficits seen in AD, while others have argued for multiple cognitive processes. As deficits in cognitive abilities may reflect the pathological process or processes occurring in AD, determination of the structure of abilities in AD is important.
  
  
  OBJECTIVE
  The purpose of this study was to assess the utility of single and multiple ability factor models in differentiating patients with AD from normals.
  
  
  RESULTS
  Findings show that although a single factor model accounts for a large part of the variability of a battery of measures used to differentiate patients and normals, a multiple factor model performed substantially better based on multiple fit criteria.
  
  
  CONCLUSIONS
  At least in this sample, a multiple ability factor model of cognitive abilities fit data better than a single factor model in differentiating patients with AD from normals.
authors.affiliation: Center on Aging and the Department of Psychiatry and Behavioral Sciences, University of Miami School of Medicine, Miami, Florida 33140, USA. rownby@med.miami.edu
authors.forename: Raymond L
authors.initials: RL
authors.lastname: Ownby
authors.forename: David A
authors.initials: DA
authors.lastname: Loewenstein
authors.forename: Lynn
authors.initials: L
authors.lastname: Schram
authors.forename: Amarilis
authors.initials: A
authors.lastname: Acevedo
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000523:psychology; D003072:Cognition Disorders / Q000175:diagnosis* / Q000523:psychology; D003937:Diagnosis, Differential; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis* / Q000523:psychology; D015233:Models, Statistical; D009483:Neuropsychological Tests; D014706:Verbal Learning