A psychophysiological and driving performance evaluation of focal and ambient visual processing demands

Research has focused little on the ambient and focal visual channels within which driving and side-task information can be processed. The purpose of the current study was two-fold: (1) to demonstrate the differentiation of focal and ambient visual processing attentional demands on driving performance and cardiovascular response in a dual-task driving environment, and (2) to confirm the utility of autonomic space for the assessment of psychological processes during dual-task driving and side-task performance.;64 subjects participated in a dual-task driving simulation that contained focal and ambient components. During the driving task subjects had to maintain lateral (the ambient component) and longitudinal (the focal component) control of the vehicle. During the side-task, subjects either had to perform a letter recognition task (the focal side-task), or a gauge detection task (the ambient side-task). Subjects participated in two levels of each driving component and each side-task.;It was hypothesized that the ambient side-task would not have any effects on driving performance, whereas the focal-side-task would cause a deterioration in the maintenance of longitudinal control. Further it was hypothesized that dual-task driving with ambient side-task performance would not have any effects on physiological response, whereas dual-task driving with focal side-task performance would elicit changes in sympathetic activity. Support for these hypotheses would provide evidence that focal visual processing is attention demanding, whereas the processing of ambient visual information is not. Further, it would also provide additional evidence for the utility of autonomic space in driving research.;Support for the hypotheses was mixed. Some results suggest that ambient visual information was processed pre-attentively, whereas focal visual information requires attentional resources to be processed. The maintenance of longitudinal control deteriorated when the focal side-task was added to driving, but not when the ambient side-task was. Further, there was no effect on the maintenance of lateral control when the ambient or the focal side-task was added to driving. However, other results failed to provide evidence for the notion that ambient visual information can be processed pre-attentively. For example, the maintenance of longitudinal control was not affected by an increase in focal side-task difficulty, but it improved as ambient side-task difficulty increased. In addition, there was no effect of dual-task driving with focal or ambient side-task performance on sympathetic activity. Finally, analyses of autonomic space during the driving task were consistent with previous studies and provide further evidence for the utility of autonomic space for the assessment of psychological processes in driving research.