Vision modulates with the progression of step: Peak of performance changes with eccentricity and task but not ground slope

Abstract

Majority of the research into the perception of individuals has been conducted in static, limited, and controlled environments. With the advent of new technologies, mobile and wearable virtual reality in particular, it is now possible to expand our understanding of perceptual phenomena to moving individuals. In this thesis, three studies are presented that leverage the consistency in walking patterns to contribute to the recent research into the changes individuals’ visual perception undergo over the course of a step. The first study expanded on a novel finding of a sinusoidal modulation in visual detection performance across a stride cycle by testing whether the modulation differs between central and peripheral vision. The results unveiled a larger modulation that peaked later in the stride cycle for the detection of peripherally presented targets as opposed to centrally presented targets. In the second study, the difference between the performance in two visual tasks, orientation and motion identification, was investigated. Results showed a phasic difference between the modulations in visual orientation identification and motion identification performance. The third study changed the walking conditions instead of the visual task to probe whether the motor demands of walking was the primary driver of the modulations in visual perception. The results were unexpected in that sloped walking did not shift the peak of performance along the course of the step but instead a second peak was found for inclined walking. Overall, these findings highlight the need to investigate the influence of walking, and more broadly, the influence of active movements on individuals’ perceptual experiences.