Abstract
270,000 pedestrians die of road traffic accidents and millions are injured each year. Children and older adults are overrepresented in these groups. However, little is known about the perceptual processes used by vulnerable pedestrians. To investigate perceptual processes involved in road-crossing, we monitored visual exploration and road-crossing decisions in children from 5 to 15 years-old, adults aged 18-25, and older adults aged 60 or above while they watched road-traffic videos containing distractors (people) and a range of traffic densities. Data-driven clustering approaches found a critical age of under 10 at which children are more likely to cross the road in short gaps. Interestingly, decision biases under 10 were associated with visual biases. While the maximum gaze distributions were at the start of the vehicle's' trajectory for all age groups, gaze similarity matrices (GSMs) revealed more varied gaze patterns across trials for children under 10 than for adolescents, young and older adults. iMap4 (Lao et al., 2017) showed that the variability in gaze patterns for children under 10 can be explained by gaze towards distractors irrelevant to the road-crossing task (human beings) and towards approaching vehicles when the traffic density is high. For all age groups oculomotor characteristics are impacted by distractors and traffic density, suggesting attentional capture. We propose that adolescents, younger and older adults are able to inhibit gaze orientation towards irrelevant stimuli; thus maintaining their gaze to the optimal location for the task. In contrast, children under 10 are less able to inhibit orientation towards irrelevant stimuli thus reducing access to diagnostic information, impacting their decisions. Older adults showed similar general gaze patterns to younger adults except for specificities when using fine-grained temporal analyses based on automatic image processing. Older adults' vulnerability is discussed in terms of delays in attention allocation, decisions, and decline in executive functioning.
Meeting abstract presented at VSS 2018