Psychomotor Vigilance Test: Measuring Reaction Time In An Occupationally Relevant Environment

Psychomotor vigilance tests are used to assess vigilant attention, typically to examine the effect of sleep deprivation or shiftwork. Traditionally, these tasks are computer-based to provide a controlled, reliable setting. Among military or public safety personnel, it is important to test reaction time (RT) in a more realistic environment (virtual reality; VR) to better assess job readiness. PURPOSE: To determine if RT is similar between the computer setting and a virtual marksmanship simulator. METHODS: Thirty-one individuals (24.5 ± 5.3 years; 94% male) with rifle experience participated in one research session. The two testing environments were randomized and both RT tests were completed in one environment before the other. For the low workload version, targets appeared every two seconds and for the high workload version, targets appeared at a random interval between 2-10 seconds. There were 30 stimuli total for each task. Computer tasks were completed on an online testing platform with a keyboard and the VR tasks were completed in an immersive marksmanship simulator with a carbon dioxide-operated rifle. A paired samples t-test was used to determine if workload influenced RT on the computer and VR similarly using difference scores (high-low). Percentage bend correlation coefficients, a robust metric, were calculated to examine the relationship between computer and VR for the low and high tasks, respectively. RESULTS: The computer-based RT values for the low and high workloads were 308.8 ± 31.1 ms and 375.7 ± 32.5 ms, respectively (difference = 65.5 ± 24.8). The VR-based RT values for the low and high workloads were 610.3 ± 137.9 ms and 687.0 ± 183.7 ms, respectively (difference = 76.7 ± 119.8). The influence of workload was not significantly different between environments (P = 0.622). Longer reaction times on the computer were associated with longer reaction times in VR for the high workload (rpb = 0.541, P = 0.002), but not low workload (rpb = 0.320, P = 0.080). CONCLUSIONS: Despite the significant increase in RT in the VR system due to the additional motor component (pulling the trigger), performance was similar between environments, especially with greater task difficulty. Utilizing VR in military or public safety groups may provide an acceptable and more occupationally relevant environment to assess job readiness. Supported by: VirTra provided research support for the project.