title: Misidentifying a tennis racket as keys: object identification in people with age-related macular degeneration.
abstract: OBJECTIVE
  Previous studies showed that people with age-related macular degeneration (AMD) can categorise a pre-defined target object or scene with high accuracy (above 80%). In these studies participants were asked to detect the target (e.g. an animal) in serial visual presentation. People with AMD must rely on peripheral vision which is more adapted to the low resolution required for detection than for the higher resolution required to identify a specific exemplar. We investigated the ability of people with central vision loss to identify photographs of objects and scenes.
  
  
  METHODS
  Photographs of isolated objects, natural scenes and objects in scenes were centrally displayed for 2 s each. Participants were asked to name the stimuli. We measured accuracy and naming times in 20 patients with AMD, 15 age-matched and 12 young controls.
  
  
  RESULTS
  Accuracy was lower (by about 30%) and naming times were longer (by about 300 ms) in people with AMD than in age-matched controls in the three categories of images. Correct identification occurred in 62-66% of the stimuli for patients. More than 20% of the misidentifications resulted from a structural and/or semantic similarity between the object and the name (e.g. spectacles for dog plates or dolphin for shark). Accuracy and naming times did not differ significantly between young and older normally sighted participants indicating that the deficits resulted from pathology rather than to normal ageing.
  
  
  CONCLUSIONS
  These results show that, in contrast to performance for categorisation of a single pre-defined target, people with central vision loss are impaired at identifying various objects and scenes. The decrease in accuracy and the increase in response times in patients with AMD indicate that peripheral vision might be sufficient for object and scene categorisation but not for precise scene or object identification.
authors.affiliation: Laboratoire Neurosciences Fonctionnelles et Pathologies, Le Centre National de la Recherche Scientifique, Université Lille Nord de France, Lille, France.
authors.forename: Miguel
authors.initials: M
authors.lastname: Thibaut
authors.forename: Thi Ha Chau
authors.initials: TH
authors.lastname: Tran
authors.forename: Céline
authors.initials: C
authors.lastname: Delerue
authors.forename: Muriel
authors.initials: M
authors.lastname: Boucart
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000150:complications / Q000503:physiopathology / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010468:Perceptual Disorders / Q000209:etiology* / Q000503:physiopathology; D010775:Photic Stimulation / Q000379:methods; D010781:Photography; D011601:Psychophysics; D015354:Vision, Low / Q000209:etiology / Q000503:physiopathology / Q000523:psychology; D014792:Visual Acuity / Q000502:physiology; D014794:Visual Fields / Q000502:physiology; D055815:Young Adult
keywords: low vision; macular degeneration; object recognition; scene and eye movement