Article

Previous research has shown that accurate stepping involves the fixation of gaze
on the intended step location. One possible explanation for this visual strategy
is that the fixation of locations that are eccentric relative to the step target,
results in systematic localization errors, as has previously been demonstrated in
pointing. To test this idea, we assessed the possible role of gaze stabilization
in the spatial planning of accurate steps, and determined whether the direction
of mediolateral stepping errors depended on the direction of gaze. Final foot
position was recorded from ten healthy participants when making steps towards
prints of their own foot, in light and in darkness, and fixating their gaze on
(i) the stepping target or (ii) locations 30 cm to the left or right of the
target. The results showed that accuracy and precision of foot placement were
reduced when stepping in darkness or when fixating eccentric gaze targets,
demonstrating that visual feedback on the target and/or foot facilitates spatial
control of the foot, and that foveal information is superior to perifoveal
information in this respect. Crucially, the direction of the mediolateral
stepping errors depended on the direction of gaze: on average participants
overstepped 12 mm contralateral to the direction of gaze when fixating eccentric
locations, indicating that the fixation of locations eccentric to the stepping
target results in inaccuracies in foot placement. These results provide new
insights into the contributions of foveal vision to the spatial planning of
precise steps, and explain why it is important to look where you step when
accurate foot placement is required.
CI - Copyright (c) 2012 Elsevier B.V. All rights reserved.

Langue : ANGLAIS