Avoidance behaviours of young adults during a head-on collision course with an approaching person.

Individuals use visual information to guide their avoidance behaviours. More specifically, individuals may directly perceive the time prior to colliding with an approaching obstacle (i.e., time to contact, TTC) to determine when to avoid. In addition, individuals use body-scaled information to control their movements. These avoidance behaviours differ when avoiding a human obstacle compared to an inanimate object. As such, the purpose of this experiment was to examine the avoidance behaviours of individuals during a head-on collision course with an approaching person. Young adults (N = 20, [Formula: see text] = 22.25 ± 1.5 years, 10 males) were instructed to walk along a 10 m path towards a goal located along the midline. A female confederate positioned along the midline walked towards the participants to one of the four predetermined final positions: (1) along the midline in the participants' starting position; (2) stopped along the midline 2.5 m from her starting position; (3) to the left of the participants' starting position; and (4) to the right of the participants' starting position. Results revealed when the path of the confederate was certain, individuals used a greater TTC to determine when to change their path in comparison with when the path of the confederate was uncertain. Males were found to avoid significantly earlier (i.e., larger TTC) than females. However, following a change in path, sex did not impact the avoidance behaviours of the groups, but rather, the environment was the regulating factor.