The Development of Perception-Action Tuning: Implications for Children’s Road-Crossing Safety

• In Event: 1-203 - The development of visual-motor integration during activities of daily living: From research to translation

Integrative Statement

This presentation overviews our program of research on perceiving and acting on dynamic affordances (i.e., possibilities for action that vary over time). Our goal is to bridge the divide between basic and applied research by using road crossing as a model system for studying how children’s ability to perceive and act on dynamic affordances undergoes change with age and experience (Plumert & Kearney, 2014, 2018). Road crossing is a complex perception-action task with two critical components: selecting a gap in traffic that affords crossing and coordinating movement through the gap. A gap affords crossing if the individual’s (projected) crossing time is less than the temporal size of the gap. To coordinate movement through the gap successfully, individuals must cut in closely behind the lead vehicle in the gap while crossing before the tail vehicle reaches their line of travel. Importantly, given the dynamic nature of traffic, gap decisions and crossing movements must be tightly linked in time.
We use state-of-the-art bicycling and pedestrian simulators to safely and systematically study how children and adults cross roads with traffic (Figure 1). The basic task for participants is to cross a virtual road with continuous cross traffic without being “hit” by a vehicle. Bicyclists ride up to each intersection and attempt to cross without being “hit” by a car. Once they reach the other side, they continue riding to the next intersection. Similarly, pedestrians stand at the edge of the roadway and attempt to cross without being “hit” by a car. Once they reach the other side, they walk back across the empty road to the starting position. Key measures include the size of the gap accepted on each trial, as well as how participants time their entry into the gap relative to the lead car and how much time to spare they have when they clear the roadway.
One of the most noteworthy findings from our work is the long developmental time course of children’s road-crossing skills, both for walking and bicycling across roads. Even when walking across a single lane of traffic, we do not see adult-like gap decisions and movement timing until age 14. Another important characteristic of the developmental changes we observe is that they are quantitative rather than qualitative in nature. Children and adults perform the tasks similarly, but children do so less skillfully than adults. The primary change with increasing age is gradual improvement in choosing gaps and timing movement, and in tightly and consistently linking gap decisions and movement timing. In terms of the developing perception-action system, we see these specific improvements with age in the road-crossing task as part of more general improvements in moving the self in relation to other moving objects. These gradual, continuous age changes in decision making and movement timing skills highlight the prolonged developmental processes in tasks that require precise tuning of perception and action. Further work aimed at better understanding the developmental mechanisms underlying these changes will inform the fields of both developmental science and injury prevention.

Authors

• Jodie Plumert, University of Iowa
  Presenting Author

• Joseph K Kearney, University of Iowa
  Non-Presenting Author