Determining the effectiveness of vestibular (balance) and ocular (eye movement) motor function screening assessments for identifying sleepy drivers.

Materials: Trial of: Vestibular and Ocular Movement (VOMs) assessments conducted with the Neuroflex(R) Virtual Reality (VR) headset device (VR headset hardware= FOVE) used to determine how effective this methodology is for predicting poor driving and cognitive performance. VOMS: VOMs compared to SLEEPINESS as detected by currently accepted methodologies: Karolinska Drowsiness Test (objective sleepiness) and Karolinska Sleepiness Scale (subjective sleepiness). VOMs compared to PERFORMANCE as detected by AusEd driving simulator metrics including speed and steering deviations, and general cognitive performance as detected by psychomotor vigilance task (PVT) metrics including higher reaction time (RT) latencies. Procedures: Driving and cognitive performance will be compared with a mixed subjects design. A) individuals’ performance will be compared within-subject first 1-hour post waking, and second 25-hours post waking. This intervention will provide information about the impact of sleepiness on performance, and the capacity of vestibular and ocular assessments to represent that sleepiness/performance decline. B) the same cohort of participants as that used in the within-subjects analysis will be divided for a between-subjects analysis with those individuals who demonstrate a trait for alertness failure and those who demonstrate a trait for alertness-failure resistance as determined by a cluster analysis that will divide participants into two separate groups. These comparisons will be made at points of critical alertness failure such as the early morning, which will reflect both the impact of sleep restriction and circadian phase on performance and vestibular and ocular assessments. Who and Mode of Delivery and location: Intervention delivered by researcher instructions. Healthy Participants will be invited to the Flinders Health and Medical Research Institute (FHMRI) / Adelaide Institute for Sleep Health (AISH) sleep laboratory to 1) meet a researcher and trial the experimental materials, and 2) to complete a diagnostic sleep study followed by five test batteries interspersed with breaks rotating every 6-hours, including one starting at 1-hour post wake, and the final starting at 25-hours post wake. Between these laboratory visits, participants will complete home activity and sleep monitoring for two weeks. Number of times (including duration/intensity/dose): All Participants will have two-weeks of baseline home observations consisting of 1-week of reporting their natural sleep patterns and 1-week of the same self-selected bed/wake times with 9-hour windows, the timing of which will be replicated during the laboratory phase. Following the night of sleep observed in the FHMRI/AISH sleep laboratory with the self-selected window, participants will remain in the sleep laboratory and undergo one period of wakefulness with cognitive battery assessments between the following hours: Day 1 8am-12.30pm, 2-6:30pm, 8pm-12:30am on day 2, day 2 2-6:30am, 8am-12.30pm. The order of testing in each battery is as follows: VOMs assessments pre and post the Aused driving simulator, followed by the objective and subjective sleepiness assessments with the Karolinska Drowsiness Test and Karolinska Sleepiness Scale and vigilance tasks with the Psychomotor Vigilance Task following the post-driving simulator VOMS. Adherence: Recruitment/adherence etc. will be monitored and represented in a consort diagram as relevant to published and presented works that are derived from this study.