Joint Action in a Virtual Environment: Crossing Roads with Risky vs. Safe Human and Agent Partners.

This paper examines how people jointly coordinate their decisions and actions with risky vs. safe human and agent road-crossing partners (Fig. 1 ). The task for participants was to physically cross a steady stream of traffic in a large-screen virtual environment without getting hit by a car. The computer-generated (CG) agent was programmed to be either safe (taking only large gaps) or risky (also taking small gaps). The human partners were classified as safe (taking more large gaps) or risky (also taking some small gaps) based on their average gap size selection. We found that participants in all four conditions preferred to cross with their partner. As a consequence, the riskiness of the partner (both human and agent) influenced the riskiness of participants' gap choices. We also found that participants tightly synchronized their movement with both human and agent partners. The largest differences in performance between those paired with agent vs. human partners occurred on trials when participants crossed different gaps than their partners. This study demonstrates the potential for studying how people interact with CG agents when performing whole-body joint actions using large-screen immersive virtual environments.

Changes in perception-action tuning over long time scales: How children and adults perceive and act on dynamic affordances when crossing roads.

This investigation examined developmental change in how children perceive and act on dynamic affordances when crossing roads on foot. Six- to 14-year-olds and adults crossed roads with continuous cross-traffic in a large-screen, immersive pedestrian simulator. We observed change both in children's gap choices and in their ability to precisely synchronize their movement with the opening of a gap. Younger children were less discriminating than older children and adults, choosing fewer large gaps and more small gaps. Interestingly, 12-year-olds' gap choices were significantly more conservative than those of 6-, 8-, 10-, and 14-year-olds, and adults. Timing of entry behind the lead vehicle in the gap (a key measure of movement coordination) improved steadily with development, reaching adultlike levels by age 14. Coupled with their poorer timing of entry, 6-, 8-, and 10-year-olds' gap choices resulted in significantly less time to spare and more collisions than 14-year-olds and adults. Time to spare did not differ between 12-year-olds, 14-year-olds, and adults, indicating that 12-year-olds' more conservative gap choices compensated for their poorer timing of entry. The findings show that children's ability to perceive and act on dynamic affordances undergoes a prolonged period of development, and that older children appear to compensate for their poorer movement timing skills by adjusting their gap decisions to match their crossing actions. Implications for the development of perception-action tuning and road-crossing skills are discussed. (PsycINFO Database Record