Controlling steering and judging heading: Retinal flow, visual direction, and extraretinal information.

Abstract

The contribution of retinal flow (RF), extra retinal (ER), and egocentric visual direction (VD) information in locomotor control was explored. First, the recovery of heading from RF was examined when ER information was manipulated; results confirmed that ER signals affect heading judgments.Then the task was translated to steering curved paths and the availability and veracity of VD was manipulated with either degraded or systematically biased RF. Large steering errors resulted from selective manipulation of RF and VD, providing strong evidence for the combination of RF, ER, and VD. The relative weighting applied to RF and VD was estimated. A point-attractor model is proposed that combines redundant sources of information for robust locomotor control with flexible trajectory planning through active gaze.

Active gaze, visual look-ahead, and locomotor control.

“…Fajen and Warren (2003) make the case for considering the perceptionaction cycle as a dynamical system, but do not address the issue of the pick-up of information or where WILKIE, WANN & ALLISON -ACTIVE GAZE, VISUAL LOOK-AHEAD AND LOCOMOTOR CONTROL 4 someone might attend during locomotion. Wilkie and Wann (2002, 2003a, 2006 followed this lead and evaluated the information used to support steering. Our model suggests that appropriate patterns of gaze sampling can simplify the perceptual control of steering.…”

“…steering at 200% target drift). Though simple solutions should always be considered, empirical data has shown that in more complex locomotor situations a number of additional sources of information play a role in human control of steering (Warren, Kay, Zosh, Duchon, & Sahuc, 2001;Wilkie & Wann, 2002;2003a;.…”

“…steering at 200% target drift). Though simple solutions should always be considered, empirical data has shown that in more complex locomotor situations a number of additional sources of information play a role in human control of steering (Warren, Kay, Zosh, Duchon, & Sahuc, 2001;Wilkie & Wann, 2002;2003a;.A more sophisticated model is therefore required to provide a good fit for human steering performance which can take advantage of multiple information sources. A popular approach has been to use non-linear dynamical models to couple perception to action (e.g.…”

Cortical dynamics of navigation and steering in natural scenes: Motion-based object segmentation, heading, and obstacle avoidance

“…The use of heading by humans during navigation has been contested (Rushton et al, 1998;Wilkie & Wann, 2003, 2006. In some cases, goal position relative to the navigator's position is sufficient to explain human steering data.…”

A neural model of how the brain computes heading from optic flow in realistic scenes

“…The use of heading for navigation has been contested by Rushton et al (1998) and Wilkie & Wann (2003 who have claimed that goal position information in relation to self is sufficient to explain human steering data. Warren et al (2001) have shown that humans can make use of both strategies and suggest that, in featureless environments where heading is hard to estimate, egocentric goal position information is used, but in richer environments, heading is used.…”