title: Cognitive and vision loss affects the topography of the attentional visual field.
abstract: OBJECTIVE
  The attentional visual field (AVF), which describes a person's ability to divide attention and extract visual information from the visual field (VF) within a glance, has been shown to be a good predictor of driving performance. Despite this, very little is known about the shape of the AVF and the factors that affect it. The purposes of this study were to describe the AVF in a large sample of older drivers and identify demographic, cognitive, and vision factors associated with AVF performance and shape.
  
  
  METHODS
  Registered drivers between 67 and 87 years of age, residing in Greater Salisbury, Maryland, were recruited to participate in the study. Participants underwent a battery of visual and cognitive assessments and completed various questionnaires for demographics, medical history, and history of depression. The AVF was assessed using a divided-attention protocol within the central 20 degrees radius along the four principal meridians. The shape of the AVF was classified as either symmetric or one of two asymmetric shape profiles.
  
  
  RESULTS
  Symmetrically shaped AVFs were found in just 34% of participants. AVF performance was significantly better along the horizontal (15.3 degrees ) than the vertical (11.3 degrees ) meridian (P < 0.05). After adjusting for AVF area, we found that poorer cognitive and vision performance was associated with a symmetric AVF shape. Overall AVF extent was predicted by vision and cognitive measures as well as various demographic factors.
  
  
  CONCLUSIONS
  Good vision and cognitive ability appear to be associated with having an asymmetric as opposed to a symmetric AVF shape profile.
authors.affiliation: Lions Vision Center, Wilmer Eye Institute, Johns Hopkins University School ofMedicine, Baltimore, Maryland, USA.
authors.forename: Shirin E
authors.initials: SE
authors.lastname: Hassan
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Turano
authors.forename: Beatriz
authors.initials: B
authors.lastname: Muñoz
authors.forename: Cynthia
authors.initials: C
authors.lastname: Munro
authors.forename: Karen Bandeen
authors.initials: KB
authors.lastname: Roche
authors.forename: Sheila K
authors.initials: SK
authors.lastname: West
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001334:Automobile Driving; D003072:Cognition Disorders / Q000503:physiopathology*; D015350:Contrast Sensitivity / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008396:Maryland; D008609:Mental Status Schedule; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D011795:Surveys and Questionnaires; D014786:Vision Disorders / Q000503:physiopathology*; D015348:Vision, Binocular / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology*