Timing and correction of stepping movements with a virtual reality avatar

Abstract

MTE) ¶ These authors contributed equally to this work. & These authors also contributed equally to this work.The effectiveness of simple sensory cues for retraining gait have been demonstrated, yet the feasibility of humanoid avatars for entrainment have yet to be investigated. Here, we describe the development of a novel method of visually cued training, in the form of a virtual partner, and investigate its ability to provide movement guidance in the form of stepping.Real stepping movements were mapped onto an avatar using motion capture data. The trajectory of one of the avatar step cycles was then accelerated or decelerated by 15% to create a perturbation.Healthy participants were motion captured while instructed to step in time to the avatar's movements, as viewed through a virtual reality headset.Step onset times were used to measure the timing errors (asynchronies) between them. Participants completed either a visual-only condition, or auditoryvisual with footstep sounds included.Participants' asynchronies exhibited slow drift in the Visual-Only condition, but became stable in the Auditory-Visual condition. Moreover, we observed a clear corrective response to the phase perturbation in both auditory-visual conditions. We conclude that an avatar's movements can be used to influence a person's own gait, but should include relevant auditory cues congruent with the movement to ensure a suitable accuracy is achieved.

A general procedure to measure the pacing of body movements timed to music and metronome in younger and older adults

“…On average, negative mean asynchronies were observed in the tapping task, whereas positive mean asynchronies were seen in the stepping task. These findings are consistent with those reported by other studies using whole-body stepping movements 59 . More specifically, Schaal, Sternad, Osu, and Kawato 60 differentiated between discrete and continuous movements in relation to the effects of auditory cueing on the nature of the errors made in sequential motor timing.…”

Adapting Footfall Rhythmicity to Auditory Perturbations Affects Resilience of Locomotor Behavior: A Proof-of-Concept Study

“…The magnitude of perturbations to the auditory stimuli used in the majority of published literature to date has been selected somewhat arbitrarily and discordantly: phase shifts of 50 ms ( Chen et al, 2006 ); 60° ( Roerdink et al, 2009 ; Nijs et al, 2020 ); 100 ms ( Wright et al, 2014 ); and 15% of step cycle ( Khan et al, 2020 ). In the present study, we perturbed the metronome cues based on each individual’s step time variability (measured in standard deviations).…”

“…Importantly, the extent to which footfall rhythm influences stability may also depend on the rhythm perception ability of the participants [instructing poor rhythm perceivers to synchronize could incur instability ( Ready et al, 2019 )] and the magnitude of perturbations ( Dotov et al, 2019 ). As more studies including rhythm perturbations are now emerging ( Krasovsky et al, 2013 ; Wright et al, 2017 ; Geerse et al, 2020 ; Khan et al, 2020 ; Nijs et al, 2020 ), it is timely to identify the governing principles and detail the involvement of dynamic stability during movement adaptation to rhythm perturbations: hence addressing the fundamental question of how footfall rhythmicity interacts with whole-body balance during walking.…”

The Components of Interpersonal Synchrony in the Typical Population and in Autism: A Conceptual Analysis

“…There is evidence that efficient multisensory integration supports IS. For example, synchronisation of both fine and gross motor activity was achieved with significantly greater accuracy when multisensory stimuli were available, as compared with when stimuli were unisensory only ( Elliott et al, 2010 ; Su, 2014 ; Wright et al, 2014 ; Khan et al, 2020 ). Further, increased multisensory acuity was significantly associated with increased spontaneous IS ( Noel et al, 2018 ).…”