Senior road users have increasingly been gaining attention of traffic psychology and accident research in the recent years. As the proportion of elderly people in the overall population continues to expand, their share as drivers and as road users in general increases as well. The types of driving errors made by elderly drivers in accidents differ from those by younger people. These errors can be traced back to particular agerelated decline in sensory, cognitive, and motor capabilities. Therefore, looking at these differences is an approach to investigate feasibility of and requirements on technical assistance for elderly drivers. One option is to counteract the reduction of the Useful Field of View (UFOV). Age-related difficulties in visuo-spacial information processing are thought to be related to the decrease of the UFOV, and thereby correlated to impaired processing speed and attentional control. Prior laboratory studies by the BASt (German Federal Highway Research Institute) investigated attention processes and the field of view using dual task paradigms. They revealed decreased reaction times and accuracy levels of elderlies’ responses to bilateral peripheral light signals in the 60° visual angle compared to stimuli at 20°. Results of analyses of event-related potentials (ERP) from the corresponding electroencephalography (EEG) data indicate that decreasing performance of the elderly is not caused by impaired vision, but by difficulties in cognitive attention mechanisms. Based on these results a literature review was conducted and followed by two combined studies featuring a laboratory setting and a driving simulator. By transferring the paradigm into a more realistic environment, it was assessed how a Visual Field Assistant may help drivers (especially elderly drivers) to recognize traffic-related objects in the peripheral field of view. Such an assistance system would be capable of transferring peripheral traffic information to the central field of vision in such a way that drivers’ attention can be lead to the indicated direction. Also response time can be reduced and responsiveness can be increased. In both parts of the study, a group of seniors (65+) was compared to a younger control group. Brake response times and eye-tracking data were recorded. Drivers had to give the right of way at intersections. Vehicles appeared in the periphery of the field of view (at a visual angle of 60°) – in half of the cases with an additional, centrally positioned warning saying Achtung! (German: Caution!). As soon as participants perceived those, they had to brake. In the first experiment additional EEG data was collected, to illustrate neuronal processing during driving in a simulation, and to obtain information about potential differences between the conditions (warning or not) and the age groups. To meet the EEG methodological requirements, the simulation scenario consisted of a dense sequence of many similar intersection situations. The second experiment focused on a more realistic scenario in the driving simulator with fewer intersections, but more diverse situations concerning right of way. Coherent with expectations, the results show that both age groups responded faster to cars in the periphery in trials with a centrally located warning. (Author/publisher)
Abstract