Locomotor avoidance behaviours during a visually guided task involving an approaching object.
Collision avoidance behaviours in situations where a collision may occur and one's planned movement is restricted, reveals that one's response is not as simple as a visual input producing some motor output. In this study, the participants (N=6) walked along a 9.5m path towards an air-filled human doll (180 degrees from their travel path) that would approach them on some trials. A spatial constraint (i.e. doorframe) was placed along the path and the participants had to determine if they could pass through the constraint prior to avoiding a collision or not. The constraint was set-up so that it was either at the theoretical collision point or 1.5m before or after the theoretical collision point. This study aimed to determine: (1) how the presence of a spatial constraint affects one's ability to perceive when to avoid a collision with an approaching object; (2) if the individuals use action parameters (i.e. velocity modifications, change in heading, etc.) in a consistent manner independent of the spatial constraint location and object's approach velocity; (3) if a consistent safety zone exists independent of the object's approach velocity. The results showed that the placement of the spatial constraint, but not the velocity of the object had a significant effect on the initiation of a change in heading. Participants used two-stage avoidance behaviour; change heading and then adjust walking velocity. The initial avoidance behaviour was initiated when the object was at a constant distance away (i.e. 3.73 m). Overall, it appears as though collision avoidance with approaching objects has cognitive as well as perceptual influences.
Gait and Posture Laboratory, Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada. Michael_Cinelli@brown.edu
Michael E
ME
Cinelli
Aftab E
AE
Patla
D000056:Accident Prevention; D000328:Adult; D006801:Humans; D009068:Movement; D013037:Spatial Behavior / Q000502:physiology; D013647:Task Performance and Analysis; D016138:Walking / Q000502:physiology*; D055815:Young Adult