Rogers B J, 2000, "Heading in the right direction?" Perception 29 ECVP Abstract Supplement
Heading in the right direction?
B J Rogers
Using displacing prisms, Rushton et al (1998 Current Biology 8 1191) and Rogers and Allison (1999 Perception Supplement, 2a) showed that straight-line walking and cycling paths are determined principally by the egocentric direction of a target rather than the 'centre of outflow' or other optic-flow-field properties. Does this mean that optic flow plays no role in locomotor control?
Two issues were investigated in the present study. First, could the previous results have been an artifact of using displacing prisms; and, second, are walking paths (in the absence of prisms) significantly straighter when optic-flow information is available? To answer the first question we used mirror spectacles (which create none of the distortions associated with prisms) to displace egocentric visual direction. The results were identical to those found previously. To answer the second question, we measured the deviations from straightness of both walking and running paths towards either (i) a visual target in an otherwise dark room, (ii) a target located on a homogeneously textured ground plane, or (iii) a target in a cluttered environment. Locomotor paths were not significantly straighter in conditions (ii) and (iii), reinforcing our previous conclusion that optic flow plays no significant role in the control of straight-line locomotion.
These web-based abstracts are provided for ease of seaching and access, but certain aspects (such as as mathematics) may not appear in their optimum form. For the final published version of this abstract, please see
ECVP 2000 Abstract Supplement (complete) size: 1258 Kb