The influence of navigation control on cybersickness and postural stability among younger and older adults during immersive virtual reality

Head-mounted displays (HMDs) have potential for training cognitive and sensorimotor abilities among Older Adults (OA). However, their use often leads to cybersickness and modifications in postural stability, notably influenced by navigation control (passive vs. active). Age-related differences in the sensorimotor system may influence the effect of these navigation types on both cybersickness and postural stability in OA compared to Younger Adults (YA). This study examines how navigation control (passive vs. active, i.e., velocity and orientation control with a joystick) affects cybersickness and postural control in OA and YA repeatedly exposed to a virtual environment. Two participant groups (OA and YA) experienced a virtual environment under both navigation conditions, repeated five times. Participants stood on a force platform that recorded the trajectory of their Center of Pressure (CoP) and reported discomfort through the Simulator Sickness Questionnaire (SSQ). A linear and nonlinear analysis of CoP trajectory was also carried out. OA displayed a statistically significant increase in SSQ total score during active navigation compared to passive navigation, whereas there was no significant difference for the YA group. Both groups showed increases in linear variables during active navigation compared to passive navigation for most exposures, while nonlinear variables generally showed no significant differences between the two conditions. Active navigation worsens cybersickness in OA, emphasizing the need to consider such effects when assessing cognitive and sensorimotor abilities in this population, alongside potential impacts on postural stability due to the conceivable increased cognitive demands.