Article

The representation of the vertical direction is a compromise between the
directions given by the egocentric and allocentric references. Dissociations
between these two referentials in the discrimination of a biological walker which
typically refers to a model of verticality questions the coordinate system
(allocentric and/or egocentric) used to perceive it. With a point-light display
paradigm, the characteristics of an artificial walking pattern were manipulated
in order to offer to 10 healthy participants (5 men/5 women; 24.6+/-3.4 years) a
female or male locomotion which had to be identified as such. The body position
of the viewer (sitting/lying) and the walking pattern viewed (aligned/rotated in
relation to the egocentric referential) were crossed. Three indices were analyzed
and 200 trials recorded: percentage of correct identification, reaction time and
confidence score. This paper confirms the validity of the walking pattern model
since the more pronounced the gradient of the walking pattern (as female or male)
the better the recognition. Furthermore, whatever the body position, artificial
walking patterns were more easily identified when they were aligned with the
egocentric referential rather than tilted. The participant gender had no
influence on the walking pattern recognition. We conclude that the perception of
a biological walker referenced to the vertical is exclusively improved by a
representation of the spatial information in an egocentric coordinate system.
CI - Copyright (c) 2013 Elsevier B.V. All rights reserved.

Langue : ANGLAIS