Preliminary validation study of the 3-min wrist-worn psychomotor vigilance test.

The 10-min psychomotor vigilance test (PVT) is a widely used tool to assess behavioral alertness. In operational environments, however, the 3-min version of the PVT is more practicable. Under controlled laboratory conditions, we compared performance on the 3-min PVT on a wrist-worn device with the 3-min PVT on a laptop computer. We conducted two repeated measures experiments (72 participants) to assess the effects of PVT device type (laptop or wrist-worn), backlight on the wrist-worn device (on or off), ambient light (low or normal levels), and interstimulus interval (ISI). First, we compared the wrist-worn PVT (ISI of 2-10 s) with the laptop-based PVT (ISI of 1-4 s). Participants performed six PVT trials counterbalanced for order of ambient light and device type. In both ambient-lighting conditions, the median differences in PVT metrics (reaction time, response speed, and percentage of 355-ms or 500-ms lapses combined with false starts) between the laptop and the wrist-worn PVT with the backlight on were less than 4.5 %. Specifically, the median difference in reaction times was less than 10 ms. However, the standard deviation in most metrics using the wrist-worn PVT was twice that of the laptop. In a second experiment, we compared the wrist-worn and laptop PVTs with the same ISIs (1-4 s) in normal light conditions. The results suggest that PVT data can be collected reliably in the field using the wrist-worn device with the backlight on and an ISI of 2-10 s.