Citation

Poulain I, Gaignard C, Marin G, Mantel B, Bernardin D. J. Vis. 2015; 15(12): e1326.

Copyright

(Copyright © 2015, Association for Research in Vision and Ophthalmology)

DOI

10.1167/15.12.1326

PMID

26327014

Abstract

INTRODUCTION: There exists an abundant literature on navigation strategies for the visual guidance of goal-directed locomotion. Two main strategies have been documented: the optic flow strategy (OF) and the egocentric direction strategy (ED). OF is assumed to be mainly used when optic flow is densely structured (Harris and Carre, 2001; Wilkie and Wann, 2003), whereas ED would dominate when optical structure is reduced (Rushton et al., 1998; Harris and Bonas, 2002). Less is known about how one particular strategy is exploited depending upon the perceptual and motor history of each individual or upon the individual weighting of sensory information. Inter-individual differences have been found in the perception of self-rotation (Bruggeman et al., 2009) and reported, though not specifically investigated, in visually guided locomotion (Turano et al. 2005; Rusthon et al. 1998). In the present study, we aimed at examining the navigation strategy preferentially used while walking towards a visible goal.

METHOD: 27 participants, from 22 to 44 years old (11 women, 16 men), participated in the study. They were asked to walk on a treadmill toward a virtual target, while optic flow was either deviated 10° to the right of actual walking direction, or not deviated. Targets were localised straight ahead, or 20° to the left or right. Heading Error was computed as the difference between instantaneous target direction and walking direction. K-means clustering method was used to examine whether heading distribution could be decomposed into participants relying on OF (Heading Error = OF deviation) and participants relying on ED (No Heading Error).

RESULTS: Results showed a large variability in the magnitude of OF's influence, independently of saliency and availability of visual structure.

CONCLUSION: There exists important inter-individual variability in the perception and control of locomotion, with individuals forming a continuum, rather than distinct groups, from OF to ED. Meeting abstract presented at VSS 2015.

Language: en