Motion Sensitivity Tests May Determine Crash Risk Better Than Visual Acuity

Better performance on motion sensitivity tests that assess central and mid-peripheral vision may reduce crash risk, according to a study published in Ophthalmic and Physiological Optics. Visual acuity, however, fails to predict driving safety and performance, according to the report.

Researchers included 65 drivers and stratified participants into 1 of 2 groups according to age. The cohorts of younger (n=35; mean age, 25.5 years) and older (n=30; mean age, 71.0 years) individuals underwent a computer-based hazard test, plus 4 different motion sensitivity tests both centrally and at 15° eccentricity. The team assessed the minimum displacement to identify motion direction (Dmin), contrast detection threshold for a drifting Gabor (motion contrast), coherence threshold for a translational global motion stimulus, and direction discrimination for a biological motion stimulus in the presence of noise, according to the report.

There were no statistically significant differences in hazard performance reaction times (P =.40) or maximum hazard performance test reaction times (P =.34) between participants in the 2 age-based cohorts. Hazard perception test response time was associated with both motion contrast and Dmin centrally (both P =.02) and with Dmin peripherally (P =.005), the report shows. Age group did not affect these associations, and no significant association was identified between binocular visual acuity and hazard perception test response times (P =.29).

“[O]ur study showed that motion sensitivity tests in both central and mid-peripheral vision (Dmin and motion contrast) were associated with [hazard perception test] performance, whereas visual acuity was not,” according to the study authors. “As the [hazard performance test] has been shown to be an index of driving safety and performance, our results provide additional evidence that measurements of motion perception have the potential to contribute to the identification of unsafe road users.”

Study limitations include the exclusive use of daytime videos in the motion sensitivity tests.