Using optic flow in the far peripheral field

Abstract

Self-motion information can be used to update spatial memory of location through an estimate of a change in position. Viewing optic flow alone can create Illusory self-motion or "vection." Early studies suggested that peripheral vision is more effective than central vision in evoking vection, but controlling for retinal area and perceived distance suggests that all retinal areas may be equally effective. However, the contributions of the far periphery, beyond 90°, have been largely neglected. Using a large-field Edgeless Graphics Geometry display (EGG, Christie, Canada, field of view ±112°) and systematically blocking central (±20° to ±90°) or peripheral (viewing through tunnels ±20° to ±40°) parts of the field, we compared the effectiveness of different retinal regions at evoking forwards linear vection. Fifteen participants indicated when they had reached the position of a previously presented target after visually simulating motion down a simulated corridor. The amount of simulated travel needed to match a given target distance was modelled with a leaky spatial integrator model to estimate gains (perceived/actual distance) and a spatial decay factor. When optic flow was presented only in the far periphery (beyond 90°) gains were significantly higher than for the same motion presented full field or in only the central field, resulting in accurate performance in the range of speeds associated with normal walking. The increased effectiveness of optic flow in the peripheral field alone compared to full-field motion is discussed in terms of emerging neurophysiological studies that suggest brain areas dedicated to processing information from the far peripheral field.

How does the human visual system compare the speeds of spatially separated objects?

“…(However, their temporal phase task proved much more difficult when the alternating motions were orthogonal-vertical and horizontal-something not observed for our speed-discrimination task ( Fig 2C)). More generally, our finding that observers can compare the speeds of well separated arrays is consistent with the ability of observers to recognize global motion in a distributed array [53], with the evidence for cooperative processes between motions in different parts of the field [54] and with the important role of bilateral optic flow in balance and vection [31,55].…”

“…The primary roles of cells sensitive to motion contrast are thought to lie in the segregation of figure from ground, in the estimation of depth and form from motion parallax, and in the analysis of optic flow fields for the maintenance of balance and the guidance of locomotion [see e.g. 19,21,29,30,31]; and not all such cells exhibit tuning for speed [21,28]. However, if the discrimination of speed did depend on signals from intrinsically local comparators of motion, we might expect performance to deteriorate with increasing spatial separation of the stimuli.…”

A Dynamic Bayesian Observer Model Reveals Origins of Bias in Visual Path Integration

“…Yet, our results regarding biases are qualitatively similar to those of previous studies, even though those studies tested motion along a one dimensional hallway. Specifically, studies that tested visual path integration over short distances found that subjects overshoot the target (Frenz and Lappe, 2005; McManus et al, 2017) while studies that used long-range targets found the opposite (Brossard et al, 2016; Lappe et al, 2007; Redlick et al, 2001). A noteworthy departure from past studies was observed in the manner by which variability of our subjects’ responses scaled with distance.…”

Identifying the limits of peripheral visual processing in 9‐month‐old infants

“…The human infant becomes progressively able to explore the surrounding space more independently with the amount of visual information actively gathered growing dramatically. Peripheral vision plays a role in balance adjustments and the optical flow happening in the visual periphery seems to be essential for a stable standing position (Horiuchi et al., 2017) and for walking (McManus et al., 2017). Also, being sensitive to moving visual targets across the visual field is critical to detect potential threats and to guide the infant's exploratory behavior.…”