Comparing Techniques to Reduce Simulator Adaptation Syndrome and Improve Naturalistic Behaviour during Simulated Driving

Electrical stimulation of the vestibular sensory system during virtual environment simulations reduces the incidence of simulator adaptation syndrome (SAS). However, interactions between vestibular stimulation and complex visual scenery can increase oculomotor symptoms. This study examined an alternative technique to reduce symptoms of SAS using the application of galvanic cutaneous stimulation of the neck. The effect of both vestibular and cutaneous stimulation was also evaluated on the naturalistic driving behaviour of curves. Thirty participants drove a rural setting virtual environment with high visual cues. Three groups of ten participants each were used to compare the effect of galvanic vestibular stimulation and galvanic cutaneous stimulation versus a control group on post drive scores of the SSQ (Simulator Sickness Questionnaire) and three driving variables (steering variability, lane position, and vehicular speed). Galvanic cutaneous stimulation while driving resulted in decreased SSQ scores, but did not show an effect on driving behaviour. Conversely, galvanic vestibular stimulation while driving curves resulted in vehicular speeds that were reflective of natural real world driving behaviour and similar SSQ scores to control. These results support the theory that cutaneous stimulation of the neck is a worthy alternative to vestibular stimulation for reducing SAS especially in scenarios requiring complex visual scenes; however, if naturalistic driving behaviour (of curves) is important, vestibular stimulation remains the better choice as it can reduce SAS symptoms (in virtual environments with low visual stimuli) and also promotes naturalistic driving behaviours.