Learner drivers with spina bifida and hydrocephalus: the relationship between perceptual-cognitive deficit and driving performance.

This study investigated the relationship between perceptual-cognitive skills and driving performance in a group of eleven learner drivers disabled by spina bifida and hydrocephalus. Perceptual-cognitive skills assessed include figure-ground discrimination, visual scanning/tracking, spatial orientation, language, reasoning and memory ability. Following ten hours driving tuition in suitably adapted cars, driving performance in off-road manoeuvres and in-traffic situations was measured. Results showed that the perceptual-cognitive skills of this group were in the low average or below average range compared to a non-handicapped population. Spearman Rank Order Correlations between clinical tests and driving performance indicated that although certain tests correlated with off-road manoeuvres, no perceptual measures were reliable indicators of in-traffic driving. There were indications that practical measures of spatial orientation and reasoning ability may be more relevant to some aspects of driving than tested perceptual skills. Memory for road signs, landmarks and routes was also investigated. Accurate retention seemed more dependent on general reasoning ability than tested aspects of memory functioning. It is suggested that as clinically tested perceptual skills do not seem to be reliable indicators of driving performance, an individual's test results should not be used to deter him from learning to drive.