Knowing what's coming: Anticipatory audio cues can mitigate motion sickness.

Being able to anticipate upcoming motion is known to potentially mitigate sickness resulting from provocative motion. We investigated whether auditory cues could increase anticipation and subsequently reduce motion sickness. Participants (N = 20) were exposed on a sled on a rail track to two 15-min conditions. Both were identical in terms of motion, being composed of the same repeated 9 m fore-aft displacements, with a semi-random timing of pauses and direction. The auditory cues were either 1) informative on the timing and direction of the upcoming motion, or 2) non-informative. Illness ratings were recorded at 1-min intervals using a 11-point scale. After exposure, average illness ratings were significantly lower for the condition that contained informative auditory cues, as compared to the condition without informative cues. This knowledge, i.e. that auditory signals can improve anticipation to motion, could be of importance in reducing carsickness in domains such as that of autonomous vehicles.

Knowing What's Coming: Unpredictable Motion Causes More Motion Sickness.

OBJECTIVE: This study explores the role of anticipation in motion sickness. We compared three conditions varying in motion predictability and assessed the effect of anticipation on subsequent illness ratings using a within-subjects design. BACKGROUND: Anticipation is thought to play a role in motion sickness by reducing the discrepancy between sensed and expected sensory information. However, both the exact role and potential magnitude of anticipation on motion sickness are unknown. METHOD: Participants (N = 17) were exposed to three 15-min conditions consisting of repeated fore-aft motion on a sled on a 40-m rail (1) at constant intervals and consistent motion direction, (2) at constant intervals but varied motion direction, and (3) at varied intervals but consistent motion direction. Conditions were otherwise identical in motion intensity and displacement, as they were composed of the same repetitions of identical blocks of motion. Illness ratings were recorded at 1-min intervals using an 11-point motion sickness scale. RESULTS: Average illness ratings after exposure were significantly lower for the predictable condition, compared with both the directionally unpredictable condition and the temporally unpredictable condition. CONCLUSION: Unpredictable motion is significantly more provocative compared with predictable motion. Findings suggest motion sickness results from a discrepancy between sensed and expected motion, rather than from unpreparedness to motion. APPLICATION: This study underlines the importance of an individual's anticipation to motion in motion sickness. Furthermore, this knowledge could be used in domains such as that of autonomous vehicles to reduce carsickness.

Moving base driving simulators' potential for carsickness research.

We investigated whether motion sickness analogous to carsickness can be studied in a moving base simulator, despite the limited motion envelope. Importantly, to avoid simulator sickness, vision outside the simulator cabin was restricted. Participants (N = 16) were exposed blindfolded to 15-min lateral sinusoidal motion at 0.2 Hz and 0.35 Hz on separate days. These conditions were selected to realize optimal provocativeness of the stimulus given the simulator's maximum displacement and knowledge on frequency-acceleration interactions for motion sickness. Average motion sickness on an 11-point scale was 2.21 ±â€¯1.97 for 0.2 Hz and 1.93 ±â€¯1.94 for 0.35 Hz. The motion sickness increase over time was comparable to that found in studies using actual vehicles. We argue that motion base simulators can be used to incite motion sickness analogous to carsickness, provided considerable restrictions on vision. Future research on carsickness, potentially more prevalent in autonomous vehicles, could benefit from employing simulators.

Looking forward: In-vehicle auxiliary display positioning affects carsickness.

Carsickness is associated with a mismatch between actual and anticipated sensory signals. Occupants of automated vehicles, especially when using a display, are at higher risk of becoming carsick than drivers of conventional vehicles. This study aimed to evaluate the impact of positioning of in-vehicle displays, and subsequent available peripheral vision, on carsickness of passengers. We hypothesized that increased peripheral vision during display use would reduce carsickness. Seated in the front passenger seat 18 participants were driven a 15-min long slalom on two occasions while performing a continuous visual search-task. The display was positioned either at 1) eye-height in front of the windscreen, allowing peripheral view on the outside world, and 2) the height of the glove compartment, allowing only limited view on the outside world. Motion sickness was reported at 1-min intervals. Using a display at windscreen height resulted in less carsickness compared to a display at glove compartment height.