EFFECT OF ‘VERTICAL’ CENTRAL SCOTOMAS ON HAZARD DETECTION IN A DRIVING SIMULATOR

Title EFFECT OF ‘VERTICAL’ CENTRAL SCOTOMAS ON HAZARD DETECTION IN A DRIVING SIMULATOR
Author, Co-Author Amanda Albu, P. Matthew Bronstad, Alex Bowers, Robert Goldstein, Eli Peli
Topic
Year
2011
Day
Program Number
115386
Room
Amphitheater
Affiliation
Harvard Medical School, Schepens Eye Research Institute
Abstract PURPOSE: We previously reported that central field loss (CFL) lateral to the preferred retinal locus delays reactions to pedestrian hazards that appear in scotoma locations (Bronstad et al. 2009). Here we report detection results from participants with "vertical" CFL above or below their preferred retinal locus, areas unlikely to interfere with detection of pedestrians while driving.

METHODS: 5 participants with vertical CFL (45-85yrs, VA 20/40-20/200) and 5 age-matched normal vision controls (NV) completed 10 test drives (each about 10 minutes). Participants honked the horn as soon as they detected a pedestrian hazard, which could appear on either side of the road at one of four eccentricities (-14, -4, 4, 14 degrees relative to car heading) and walked or ran on a collision course with the participant’s vehicle. Pedestrians maintained a relatively constant eccentricity and thus stayed in the same area of the visual field for up to 3 sec after appearance. Pedestrians stopped just before entering the participant’s travel lane to avoid actual collisions.

RESULTS: CFL participants’ reaction times for pedestrians were significantly increased (median 2.73s) compared to NVs (median 1.23s) (p < 0.05). Reaction times for CFLs were long enough that they would have collided with 22% of pedestrians had the pedestrians continued on their collision course, compared with 3% for NV controls.

CONCLUSIONS: Although pedestrians likely did not fall within the scotoma, the slow responses of participants with vertical CFL increased collision risk. The reasons for this effect may be efforts to maintain eccentric viewing and a slightly larger retinal eccentricity for the participants with CFL. CFL, regardless of scotoma location, negatively impacts hazard detection while driving and should be a consideration when screening and licensing drivers.

ADDITIONAL COMMENTS: Funded in part by NIH grants EY12890 (EP) and EY018680 (ARB)
Affiliation of Co-Authors Harvard Medical School, Schepens Eye Research Institute, Harvard Medical School, Schepens Eye Research Institute, Harvard Medical School, Schepens Eye Research Institute, Harvard Medical School, Schepens Eye Research Institute
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