A simulated driving task that required the simultaneous execution of two continuous visual tasks was administered to 12 young and 12older experienced and currently active drivers. The first task was a compensatory lane-tracking task involving a 3-dimensional road display. The second task was a timed, self-paced visual analysis task involving either a vocal or manual binary response to dot patterns projected within the road display. Details of the study are described.It was found that compared with young adults, older adults showed asignificantly decreased ability to divide attention. This effect was apparent in lane tracking and in the accuracy of visual analysis. The impairment of divided attention was less pronounced in the vocalcondition than in the manual one. This suggests that difficulty in integrating responses may be an important determinant of poor dual-task performance in old age.
Abstract