Visual Attention Measures Predict Pedestrian Detection in Central Field Loss: A Pilot Study

Abstract

PurposeThe 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.Methods11 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).ResultsUFOV 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).ConclusionsOur 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.

A link between attentional function, effective eye movements, and driving ability.

“…Driving is a more complex task, and the attentional mechanisms involved in driving may not be accurately represented when performing the UFOV task. The MOT, which is a more dynamic and sustained assessment of executive control, was proposed and was found to correlate to driving performance ( Alberti, Horowitz, et al, 2014 ; Bowers et al, 2011 ). In this current study, we also found evidence to support the claims that better performance on the MOT predicts better driving performance (see Figure 6 ).…”

“…Those who performed worse on the MOT task also had higher error scores on a road test ( Bowers et al, 2011 ). In addition, MOT was found to be a stronger predictor than UFOV in predicting the ability to detect hazardous pedestrians during simulated driving in those with central visual field loss ( Alberti, Horowitz, Bronstad, & Bowers, 2014 ). These results highlight not only the link between attentional function and driving but also suggest the importance of incorporating a dynamic assessment of sustained visual attention when studying driving performance.…”

Driving with Central Visual Field Loss II: How Scotomas above or below the Preferred Retinal Locus (PRL) Affect Hazard Detection in a Driving Simulator

“…CFL participant RTs were also longer than NV for pedestrians not occluded by the scotoma. Reasons for this may include reduced contrast sensitivity due to increased retinal eccentricity and reduced attentional resources due to the effort required to maintain eccentric fixation with the PRL [ 27 , 28 ]. Our simulator studies provide a specific mechanism by which AMD may cause difficulty in driving and perhaps cessation altogether.…”

A meta-analysis of perceptual and cognitive functions involved in useful-field-of-view test performance

“…Several patient groups show poor performance on the UFOV test, including those with ophthalmological and neurological diseases (Alberti, Horowitz, Bronstad, & Bowers, 2014;Badenes et al, 2014;Classen et al, 2011;Fisk, Novack, Mennemeier, & Roenker, 2002;Rosen et al, 2015). In addition, UFOV performance declines with increasing age (Ball, Beard, Roenker, Miller, & Griggs, 1988;Edwards et al, 2006;Sekuler, Bennett, & Mamelak, 2000).…”