The project aimed in a comprehensive and systematic review of the literature concerning mobility and driving risk factors of persons with dementia. Furthermore, appropriate diagnostic procedures had to be suggested and applied within a pre-test. Accordingly, a test protocol consisting of computer-based and paper-and-pencil tests for the assessment of divided, visuo-spatial, and focused attention as well as alertness, processing of complex visual stimuli, sensomotor tasks and learning of labyrinths was developed. 46 MCI-patients, 7 patients with early Alzheimer's disease and 11 control subjects were examined and took part in an on-road test. The groups differed significantly in visual information processing, divided attention, and in visuo-spatial attention. A structural equation model was developed showing a high goodness-of-fit, and integrating the most important predictors of driving behaviour and their covariance. Hence, visuo-spatial and divided attention have highest predictive validity. Reported changes in driving habits, the avoidance of specific traffic situations, and compensatory behaviour are determined by health status (diseases, subjective physical and cognitive complaints), visual information processing (Active Visual Field) and visuo-spatial attention. A comparison of extreme groups with 16 participants with very good vs 16 participants with rather conspicous driving behaviour basically confirmed the model and demonstrated further group differences in visual processing of traffic situations and sensomotor processes. (Author/publisher)
Abstract