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RESEARCH PROJECTS |
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VISUAL FIELD LOSS & LOCOMOTION Optic-flow and egocentric-direction strategies in walking: Central vs. peripheral visual field |
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Using a virtual environment that presented participants with a goal post located in a forest, the post alone, or the forest alone with the goal presented briefly at the beginning of each trial, the extent to which individuals with peripheral field losses or central field losses rely on optic flow and/or landmarks to walk to a goal was investigated. Optic flow patterns were manipulated throughout the experiment by offsetting the participants’ virtual heading from their true heading. Participants with central field losses showed less impairment in the first two conditions than the other participants while participants with peripheral field losses showed greater impairments in the last condition than the other participants. These findings suggest that central vision is important for using optic flow to guide walking, whereas peripheral vision is important for establishing and/or updating an accurate representation of spatial structure for navigation. Movie 1 Movie of a representative young FS participant walking toward the goal (white pole) in a goal-in-forest scene with a 10_-right offset. Movies were reconstructed from head- and eye-position data. Left side displays an aerial perspective (with leaves removed for clarity). The red dot is the participant and the brown markings indicate the trunks and limbs of the trees. The blue ball indicates gaze location and is tethered to the participant by a dotted line. The brief green flash indicates the time the participant received the tone to begin walking. Right side displays the corresponding first-person view, with the cross indicating the participant's gaze location.
Movie 3
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