How Do Children Perceive and Act on Affordances When Walking vs. Bicycling across Roads?

• In Event: Poster Session 06
  In Poster Session: PS 06 Topic - Perceptual, Sensory, Motor

Abstract

Crossing roads with continuous traffic is a common, everyday task that involves perceiving and acting on affordances (Gibson, 1979). Whether bicycling or walking across roads, children must judge how long it will take for the oncoming car to arrive in relation to how long it will take to cross the street. Previous work shows that there are improvements with age in pedestrian and cyclist road-crossing skills (Plumert & Kearney, 2018). Gap choices become less risky and movement timing becomes more precise. But how does children’s performance compare when they cross roads on foot vs. on bike? The visual information is the same whether walking or bicycling across roads, but the mode of locomotion differs. If children’s relative skill and experience with walking vs. bicycling impacts how they perceive and act on gap affordances, then we should see that children’s gap choices and movement timing vary by mode of locomotion, particularly at younger ages.

Ninety-six 8-, 10-, 12-, and 14-year-old children participated. Children walked and bicycled (with task order counterbalanced) across a one-lane road in an immersive virtual environment (Figure 1). Continuous 25 mph traffic travelled from left to right, with randomly ordered temporal gaps between cars ranging from 2-5 seconds with half-second intervals. The task for participants was to cross the road without getting hit by a car. On each road-crossing trial, we measured gap selection and movement timing (timing of entry relative to the lead car when entering the gap, crossing time, and time to spare relative to the tail car when exiting the gap).

Mixed-effects logistic regression analyses of gap choices revealed that overall children were more discriminating in their gap choices when crossing roads on foot than on bike, taking fewer of the small gaps and more of the large gaps. In addition, 8- and-10-year-olds selected reliably smaller gaps and were less discriminating overall in their gap choices than 14-year-olds. Mixed-effects linear regression analyses of movement timing showed that 8-, 10-, and 12-year-olds (but not 14-year-olds) timed their entry relative to the lead car more tightly when crossing on foot than on bike (Figure 2). Eight-year-olds also crossed the road more quickly on foot than on bike, whereas 10-, 12-, and 14-year-olds crossed more quickly on bike than on foot. Finally, 8-year-olds had significantly less time to spare on bike than on foot whereas 14-year-olds had significantly more time to spare when crossing on bike than on foot.

These findings suggest that there is limited transfer from walking to bicycling in children’s ability to perceive and act on gap affordances. This is consistent with other work showing limited transfer in infants’ judgments of the reachability of an object from a sitting position to an all-fours position (Adolph, 2000). Together, this research contributes to our understanding of basic developmental change in the perceptual-motor system in late childhood and early adolescence and provides information about the ways in which immature perceptual-motor functioning contributes to increased risk for pedestrian and cyclist injuries involving motor vehicles.

Authors

• Morgan N Di Napoli Parr, University of Iowa
  Presenting Author

• Shiwen Zhou, The Georgia Institute of Technology
  Non-Presenting Author

• Elizabeth E O'Neal, University of Iowa
  Non-Presenting Author

• Joseph Kearney, University of Iowa
  Non-Presenting Author

• Jodie Plumert, University of Iowa
  Non-Presenting Author