Effects of Neck Muscle Vibration on Head-Rotation Gain Perception in Seated VR

Head-rotation gains can reduce the physical effort required to look around in seated virtual reality (VR), but their applicability is constrained by perceptual detectability and discomfort. This study investigates whether neck muscle vibration (NMV) can alter the perception of head-rotation gains during seated VR. In a within-subject study with 20 participants, we compared four vibration conditions and measured detection thresholds, subjective discomfort, and perceived controllability. We found that stimulating the sternocleidomastoid muscle contralateral to the turning direction shifted the point of subjective equality (PSE) toward larger gains. This proprioceptive bias indicates that a wider range of amplified head rotation remained imperceptible, and importantly, this condition also reduced discomfort relative to other NMV conditions. These findings suggest that modulating multisensory integration via direction-dependent NMV is a promising haptic approach for seated VR techniques that benefit from modest rotation-gain amplification.