More vection means more velocity storage activity: a factor in visually induced motion sickness?

Abstract

Full-field visual rotation around the vertical axis induces a sense of self-motion (vection), optokinetic nystagmus (OKN), and, eventually, also motion sickness (MS). If the lights are then suddenly switched off, optokinetic afternystagmus (OKAN) occurs. This is due to the discharge of the velocity storage mechanism (VSM), a central integrative network that has been suggested to be involved in motion sickness. We previously showed that visually induced motion sickness (VIMS) following optokinetic stimulation is dependent on vection intensity. To shed light on this relationship, the current study investigated whether vection intensity is related to VSM activity, and thus, to the OKAN. In repetitive trials (eight per condition), 15 stationary participants were exposed to 120 s of visual yaw rotation (60°/s), followed by 90 s in darkness. The visual stimulus either induced strong vection (i.e., scene rotating normally) or weak vection (central and peripheral part moving in opposite directions). Eye movements and subjective vection intensity were continuously measured. Results showed that OKAN occurred less frequently and with lower initial magnitude in the weak-vection condition compared to the strong-vection condition. OKAN decay time constants were not significantly different. The results suggest that the stimuli that produced strong vection also enhanced the charging of the VSM. As VSM activity presumably is a factor in motion sickness, the enhanced VSM activity in our strong-vection condition hints at an involvement of the VSM in VIMS, and could explain why visual stimuli producing a strong sense of vection also elicit high levels of VIMS.

Cybersickness in Head-Mounted Displays Is Caused by Differences in the User's Virtual and Physical Head Pose

“…This hypothesis predicts that VIMS and cybersickness should: (1) never occur without vection; and (2) be more likely to occur, and more severe, during stronger vection. Consistent with the hypothesis, the findings of a number of VIMS and cybersickness studies appear to support these predictions (Hettinger et al, 1990;Flanagan et al, 2002;Smart et al, 2002;Bonato et al, 2004Bonato et al, , 2005Bonato et al, , 2008Diels et al, 2007;Palmisano et al, 2007;Nooij et al, 2017Nooij et al, , 2018Clifton and Palmisano, 2019;Risi and Palmisano, 2019). However, other studies have reported nonsignificant or negative relationships between vection and sickness Griffin, 2002, 2003;Lawson, 2005;Bonato et al, 2008;Ji et al, 2009;Chen et al, 2011;Golding et al, 2012;Keshavarz et al, 2014Keshavarz et al, , 2015Riecke and Jordan, 2015;Gavgani et al, 2017b;Palmisano et al, 2017Palmisano and Riecke, 2018;Kuiper et al, 2019;Teixeira and Palmisano, 2020).…”

Readaptation Treatment of Mal de Debarquement Syndrome With a Virtual Reality App: A Pilot Study

“…Full-field stimulation is also the most efficient way to induce circular vection (46). Additionally, the amount of circular vection is correlated with the duration of OKAN (56), which is directly related to the activation of velocity storage (47,57). Furthermore, OKAN can be induced by peripheral vision, while the central (foveal) vision is blocked or lessened (18,56).…”

“…The full-field OKN induces a sensation of body rotation in the direction opposite to stripes' motion (vection) that is indistinguishable from actual rotation in light with stripes stationary in space (46). It was recently demonstrated that amounts of vection and velocity storage are directly correlated (47). Thus, according to VOR readaptation hypotheses, when the ship is turning relative to the coastline, it induces horizontal OKN (yaw axis rotation), if the passenger is facing the ship's direction of motion.…”

Measuring optokinetic after-nystagmus: potential for detecting patients with signs of visual dependence following concussion

“…This also implies a localizing value, as these patients will have impairments (or alterations) at the level of the cerebellum, where the activity of the velocity storage is supposedly controlled. Previous studies have shown prolonged horizontal OKAN after removal of the nodulus/uvula [37].…”