Potential Use of Motion Perception Tasks in Predicting Driving Performance in the Elderly

Abstract

Abstract: : Introduction: Changes in the demographics indicates that the population older than 65 is on the rise because of the aging of the ‘baby boom’ generation. This aging trend and driving related accident statistics reveal the need for procedures and tests that would assess the driving ability of older adults and predict whether they would be safe or unsafe drivers. Literature shows that an attention based test called the useful field of view (UFOV) was a significant predictor of accident rates compared to any other visual function tests. We were interested in identifying visual perceptual tasks involving motion that would relate to the driving environment better than the regular visual function tests. The present study evaluates a qualitative trend on using motion perception tasks as a potential visual perceptual correlates in screening elderly drivers who might have difficulty in driving. Methods: Data was collected from 15 older subjects with a mean age of 71. Motion perception tasks included – speed discrimination with radial and lamellar motion, time to collision using prediction motion and estimating direction of heading. A motion index score was calculated which was indicative of performance on the all of above mentioned motion tasks. Scores on visual attention was assessed using UFOV. A driving habit questionnaire adapted from Owsley et al. (1999) was also administered to have a self report on the driving difficulties and accident rates. Results: A qualitative trend based on frequency distributions show that thresholds on the motion perception tasks rather than UFOV were more successful in identifying subjects who reported to have had difficulty in certain aspects of driving and had accidents. Specific examples will be presented. Correlation between UFOV and motion index scores was not significant indicating that probably different aspects of visual information processing that are crucial to driving behavior are being tapped by these two paradigms. A larger cross sectional study is needed for effective quantitative analysis though a trend indicative of successful use of motion paradigms was observed. Conclusions: UFOV, motion perception tasks and other basic visual functions together can be better predictor of identifying at risk or safe drivers than just using either one of them.

Keywords: aging: visual performance • vision and action • perception