Age-Related Differences of the Gaze Pattern in a Realistic Pedestrian Traffic Task

Abstract

Laboratory studies suggest that the gaze pattern changes in older age, both in seated and in walking persons. Here we investigate the gaze pattern in a more complex and realistic scenario: walking in a virtual-reality shopping precinct. Seventeen young and sixteen older adults walked at their preferred speed on a treadmill driven by their leg movements, thus controlling the presentation of a virtual 3D world on a screen 130 cm ahead. The screen showed a shopping street with stationary and moving objects, and with six pedestrian traffic lights of whom three turned red upon approach. Gaze direction was registered by a video-based system. We found that each glance at a traffic light took longer in older than in young persons, and the sum of all glances at a traffic light was longer as well. In effect, older persons looked at the traffic light equally long throughout all three light phases, while young ones gradually increased their inspection of the traffic light as the green phase went on. The observed change of the gaze pattern in older age could represent a compensatory strategy to facilitate spatial orientation and/or movement preparation, or it could reflect a deficit of gaze disengagement. Future research should disambiguate these alternatives. In any case, the observed change is detrimental for seniors' sensorimotor performance in everyday scenarios.