Abstract
Purpose :
Motorcycles are frequently involved in accidents at intersections. We developed a prototype test to measure the useful field of vision (the visual area over which information can be extracted during a brief glance) for detection of motorcycles at intersections. Unlike the commercial Useful Field of View (UFOV) test, in which peripheral high-contrast targets appear at only one eccentricity (about 10°), our test uses intersection traffic scenes with targets (motorcycles) at eccentricities up to 30°. Here we present results of a preliminary investigation of the effects of age, target eccentricity and target size on the peripheral detection field extent.
Methods :
Twelve older (> 60 y) and nine younger (< 40 y) participants viewed images of intersection traffic scenes created using our driving simulator. Each image, displayed briefly for 250ms, contained the target motorcycle amongst other traffic, appearing at 10, 20, or 30° eccentricity and subtending a vertical size of 1.3, 2.1 or 3.4° (540 images total). Participants performed the test under divided attention conditions reading aloud 1.5° letters presented at the straight ahead gaze point while simultaneously using their peripheral vision to judge whether the motorcycle appeared on the left or right side of the intersection.
Results :
Correct response rates were significantly lower for the older than the younger group (overall, 75% and 85%, respectively; p = 0.015), and decreased significantly with increasing eccentricity (p < 0.001) and decreasing target size (p < 0.001). At 10° eccentricity, there were no significant group differences (overall, 90% older and 92% younger p = 0.61); however, older subjects performed worse than younger at both 20° (overall, 71% and 88% respectively, p < 0.001) and 30° (overall, 63% and 75%, p = 0.01). For the smallest target, performance of older subjects was, on average, above chance at only the 10° eccentricity, whereas younger subjects were above chance at all eccentricities. Better performance on the prototype test correlated with better performance (lower scores) on subtest 3 (selective attention) of the commercial UFOV test (r = -0.661; p = 0.001).
Conclusions :
Our prototype test was sensitive to the effects of age, target size and eccentricity, and significantly correlated with the commercial UFOV test.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.