Rapid assessment of hand reaching using virtual reality and application in cerebellar stroke

Abstract

The acquisition of sensory information about the world is a dynamic and interactive experience, yet the majority of sensory research focuses on perception without action and is conducted with participants who are passive observers with very limited control over their environment. This approach allows for highly controlled, repeatable experiments and has led to major advances in our understanding of basic sensory processing. Typical human perceptual experiences, however, are far more complex than conventional action-perception experiments and often involve bi-directional interactions between perception and action. Innovations in virtual reality (VR) technology offer an approach to close this notable disconnect between perceptual experiences and experiments. VR experiments can be conducted with a high level of empirical control while also allowing for movement and agency as well as controlled naturalistic environments. New VR technology also permits tracking of fine hand movements, allowing for seamless empirical integration of perception and action. Here, we used VR to assess how multisensory information and cognitive demands affect hand movements while reaching for virtual targets. First, we manipulated the visibility of the reaching hand to uncouple vision and proprioception in a task measuring accuracy while reaching toward a virtual target (n = 20, healthy young adults). The results, which as expected revealed multisensory facilitation, provided a rapid and a highly sensitive measure of isolated proprioceptive accuracy. In the second experiment, we presented the virtual target only briefly and showed that VR can be used as an efficient and robust measurement of spatial memory (n = 18, healthy young adults). Finally, to assess the feasibility of using VR to study perception and action in populations with physical disabilities, we showed that the results from the visual-proprioceptive task generalize to two patients with recent cerebellar stroke. Overall, we show that VR coupled with hand-tracking offers an efficient and adaptable way to study human perception and action.

Feasibility and Tolerability of Reaching Accuracy Assessment using Virtual Reality in Subacute and Chronic Cerebellar Stroke

“…Our results con rmed a previous nding from our group that average reaching error in the neurologically healthy population is higher in the invisible hand condition than in the visible hand condition (Isenstein et al 2022). One possible explanation for this nding is that relying on proprioception alone, rather than proprioception combined with vision, leads to more reaching error.…”

“…A recent study by our group demonstrated the feasibility of using this technology to measure reaching accuracy in healthy young adults and two individuals with recent cerebellar strokes. Importantly, we were able to uncouple proprioception and vision by manipulating the visibility of the digital rendering of the hand [13].…”

Identifying applications of virtual reality to benefit the stroke translational pipeline

“…Recently, a case-control pilot study was conducted by Zúñiga et al ( 2021) assessing post-stroke motor function of the trunk and upper limb using a 3D avatar of the body to monitor movement without the attachment of markers to the subject, which showed that the VR quantification was more sensitive than clinical scales and found a correlation between the mRS and degree of body sway. Another example of VR application providing useful quantification of functional outcomes is the work of Isenstein et al (2022), whereby the authors used hand tracking VR to assess both paired visual-proprioceptive ability and isolated proprioception by making the reaching virtual hand invisible. The results of the test showed that there was a statistical significance between accuracy when the hand was visible, compared to invisible, allowing isolated proprioception to be measured sensitively within the test population.…”

The Pulfrich Effect in Virtual Reality

“…In vision science, many experiments now present stimuli in VR on head-mounted displays (HMDs) as a means to study perception under more naturalistic viewing conditions [13, 32]. Among other topics, VR has already been used to study interpersonal space [51], 3D motion perception and feedback [8], distance perception [17], scene saliency [44], proprioception with hand-tracking [16], and color awareness during naturalistic scene viewing [6]. VR technologies work by creating images that simulate the light array typically provided by the natural environment [35].…”