Action strategies for walking through multiple, misaligned apertures

• Published in: Acta psychologica 2018-01, Vol.182, p.100-106
• Main Authors: Hackney, Amy L., Cinelli, Michael E., Frank, James S.
• Format: Article
• Language: English
• Subjects: Aperture; Aperture crossing; Experiments; Gait; Goal-directed locomotion; Obstacle avoidance; Visual control of locomotion; Walking
• ISSN: 0001-6918; 1873-6297
• DOI: 10.1016/j.actpsy.2017.11.006

When avoiding obstacles, path selection is thought to be determined by the attraction of the end-goal. However for aperture crossing, it is unclear whether the attraction point originates in the center of the aperture or at the end-goal, as previous experiments align the aperture with the end-goal. The purpose of the current study was to decipher the possible location of the attraction point, by evaluating crossing behaviour for multiple, misaligned apertures. Participants were instructed to walk through three separate apertures while en route to an end-goal. The first and last apertures were fixed such that they were both either 0.9× or 1.7× shoulder width (SW) while the second aperture was either 0.9, 1.3 or 1.7× SW and shifted 25, 50 or 75cm off the midline. Findings revealed that the attraction of the end-goal, and not the middle of the aperture, guided crossing behaviour. The spatial margin decreased as the size of the shift increased. Furthermore, the frequency of rotation increased as the aperture was shifted away from midline, regardless of the aperture size. Since rotations would not normally occur for all of these aperture sizes when aligned with the end-goal, these results suggest that rotations were produced in an attempt to keep one's trajectory as close to the midline as possible. Therefore, not only does the attraction of the goal guide path trajectory, but individuals will choose to reduce the spatial margin and rotate the shoulders when walking through misaligned apertures, likely in attempt to maintain the straightest possible path. •Previous studies do not determine if aperture crossing is guided by the desire to walk through the center of an aperture or by the end-goal location.•19 participants walked through 3 separate apertures, whereby the second aperture was shifted 25, 50 or 75cm from the mid-line of the walking path.•The size of the spatial margin decreases, and the frequency of shoulder rotations increases as the size of the shift increases.•Individuals appear to be guided by the end-goal and prefer to walk the straightest possible walking path.•Previous rotations on a path increase the likelihood of a rotation occurring later on the path, even at aperture sizes where rotations are not necessary.•Suggests either a carry-over effect or an altered perception of the aperture width occurs under these contexts.