title: Characteristics of visual target influence detection of change in naturalistic scenes in Alzheimer disease.
abstract: OBJECTIVE
  To examine the role of visual characteristics of the target on Alzheimer disease (AD) patients' ability to detect change in naturalistic scenes.
  
  
  BACKGROUND
  AD patients exhibit impairments in detecting changes in the visual environment. Unexamined to date is the influence of visual characteristics of the target on this ability.
  
  
  METHODS
  The change-detection experiment used 36 pairs of photographs of naturalistic scenes. Each pair was identical except for one target that differed in color, gray-scale, or presence/absence. Scene complexity also varied. The task was to locate the target; reaction times (RTs) were recorded.
  
  
  RESULTS
  RTs increased as scene complexity increased. AD patients exhibited slower RTs than elderly adult controls (ECs), who were slower than young adults (N = 14/group). AD patients were unable to locate the target in 33.3% to 61.9% of the complex gray-scale trials, compared with 4.8% to 38.1% in the EC group. Performance on color and presence/absence trials was relatively good for all groups.
  
  
  CONCLUSIONS
  The ability of AD patients to detect change in simulated real-world scenes is influenced by visual characteristics of the target and by scene complexity.
authors.affiliation: Department of Psychology, Bridgewater State College, Bridgewater, Massachusetts 02325, USA. sneargarder@bridgew.edu
authors.forename: Sandy A
authors.initials: SA
authors.lastname: Neargarder
authors.forename: Alice
authors.initials: A
authors.lastname: Cronin-Golomb
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000523:psychology*; D001334:Automobile Driving; D003116:Color; D003118:Color Perception; D015350:Contrast Sensitivity; D005106:Exploratory Behavior / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008606:Mental Processes / Q000502:physiology; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D014787:Vision Tests