Visual capture of gait during redirected walking

Abstract

Redirected walking allows users of virtual reality applications to explore virtual environments larger than the available physical space. This is achieved by manipulating users’ walking trajectories through visual rotation of the virtual surroundings, without users noticing this manipulation. Apart from its applied relevance, redirected walking is an attractive paradigm to investigate human perception and locomotion. An important yet unsolved question concerns individual differences in the ability to detect redirection. Addressing this question, we administered several perceptual-cognitive tasks to healthy participants, whose thresholds of detecting redirection in a virtual environment were also determined. We report relations between individual thresholds and measures of multisensory weighting (visually-assisted postural stability (Romberg quotient), subjective visual vertical (rod-and-frame test) and illusory self-motion (vection)). The performance in the rod-and-frame test, a classical measure of visual dependency regarding postural information, showed the strongest relation to redirection detection thresholds: The higher the visual dependency, the higher the detection threshold. This supports the interpretation of users’ neglect of redirection manipulations as a “visual capture of gait”. We discuss how future interdisciplinary studies, merging the fields of virtual reality and psychology, may help improving virtual reality applications and simultaneously deepen our understanding of how humans process multisensory conflicts during locomotion.

Vision Affects Gait Speed but not Patterns of Muscle Activation During Inclined Walking—A Virtual Reality Study

“…Patient populations with deficiencies in the central nervous system and locomotion deficits show high visual field dependency (measured by subjective visual vertical), probably compensating for their deficits [e.g., Parkinson's disease (Bonan et al, 2006(Bonan et al, , 2007, post-stroke (Crevits et al, 2007), multiple sclerosis (Slaboda et al, 2013), and cerebral palsy (Kim et al, 2015)]. Assessments of visual dependency include tests based on visual-vestibular conflicts such as measuring visually induced illusory perception of self-motion, known as vection (Lê and Kapoula, 2008), and the Romberg's test that measures visually assisted postural stability and aims to identify the influence of vision on postural control by comparing how much the body sways with eyes opened vs. closed (Rothacher et al, 2018). In addition to the rod and frame test used in our study, Rothacher et al, used these two tests and compared them with locomotive outcomes.…”

Achronopresence: how temporal visuotactile and visuomotor mismatches modulate embodiment

“…This could suggest that the effect might be mediated by stronger visual dependence: participants with stronger visual dependence would not be so sensitive to incongruencies to other senses since they rely stronger on vision as compared to other senses (Witkin & Asch, 1948). Indeed visual dependence has shown to be correlated with susceptibility to various multisensory illusions (David, Fiori, & Aglioti, 2014;Rothacher, Nguyen, Lenggenhager, Kunz, & Brugger, 2018). A stronger dependence on visual signals could thus explain why there was no difference in the decay of ownership for visuomotor and visuotactile tasks for participants with low delay sensitivity, however we did not objectively assess such dependence.…”

Vision affects gait speed but not patterns of muscle activation during inclined walking – a virtual reality study

“…Assessments of visual dependency include tests based on visual-vestibular conflicts such as measuring visually-induced illusory perception of self-motion, known as vection (Kim et al, 2015), and the Romberg's test that measures visually assisted postural stability and aims to identify the influence of vision on postural control by comparing how much the body sways with eyes opened vs. closed (Lê and Kapoula, 2008). In addition to the rod and frame test used in our study, Rothacher et al (Rothacher et al, 2018) used these two tests and compared them to locomotive outcomes. Out of the three tests, they found that locomotive outcome showed the highest correlation to the rod and frame test by demonstrating that high visual field-dependent participants (as revealed in the rod and frame test) were the most sensitive to visual manipulations in a VR environment.…”