title: Visual attention measures predict pedestrian detection in central field loss: a pilot study.
abstract: OBJECTIVE
  The ability of visually impaired people to deploy attention effectively to maximize use of their residual vision in dynamic situations is fundamental to safe mobility. We conducted a pilot study to evaluate whether tests of dynamic attention (multiple object tracking; MOT) and static attention (Useful Field of View; UFOV) were predictive of the ability of people with central field loss (CFL) to detect pedestrian hazards in simulated driving.
  
  
  METHODS
  11 people with bilateral CFL (visual acuity 20/30-20/200) and 11 age-similar normally-sighted drivers participated. Dynamic and static attention were evaluated with brief, computer-based MOT and UFOV tasks, respectively. Dependent variables were the log speed threshold for 60% correct identification of targets (MOT) and the increase in the presentation duration for 75% correct identification of a central target when a concurrent peripheral task was added (UFOV divided and selective attention subtests). Participants drove in a simulator and pressed the horn whenever they detected pedestrians that walked or ran toward the road. The dependent variable was the proportion of timely reactions (could have stopped in time to avoid a collision).
  
  
  RESULTS
  UFOV and MOT performance of CFL participants was poorer than that of controls, and the proportion of timely reactions was also lower (worse) (84% and 97%, respectively; p = 0.001). For CFL participants, higher proportions of timely reactions correlated significantly with higher (better) MOT speed thresholds (r = 0.73, p = 0.01), with better performance on the UFOV divided and selective attention subtests (r = -0.66 and -0.62, respectively, p<0.04), with better contrast sensitivity scores (r = 0.54, p = 0.08) and smaller scotomas (r = -0.60, p = 0.05).
  
  
  CONCLUSIONS
  Our results suggest that brief laboratory-based tests of visual attention may provide useful measures of functional visual ability of individuals with CFL relevant to more complex mobility tasks.
authors.affiliation: Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Concetta F
authors.initials: CF
authors.lastname: Alberti
authors.affiliation: Basic Biobehavioral and Psychological Sciences Branch, Behavioral Research Program Division of Cancer Control and Population Sciences, National Cancer Institute, Rockville, Maryland, United States of America.
authors.forename: Todd
authors.initials: T
authors.lastname: Horowitz
authors.affiliation: Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: P Matthew
authors.initials: PM
authors.lastname: Bronstad
authors.affiliation: Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Alex R
authors.initials: AR
authors.lastname: Bowers
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001288:Attention / Q000502:physiology*; D001334:Automobile Driving; D006801:Humans; D008875:Middle Aged; D010865:Pilot Projects; D012607:Scotoma / Q000503:physiopathology*; D014785:Vision, Ocular / Q000502:physiology*; D014792:Visual Acuity / Q000502:physiology; D014794:Visual Fields / Q000502:physiology*