Validation of a portable, touch-screen psychomotor vigilance test.

INTRODUCTION

The Psychomotor Vigilance Test (PVT) measures effects of fatigue from sleep loss and circadian misalignment on sustained vigilance performance. To promote PVT use in field environments, a 5-min PVT version has been implemented on a personal digital assistant (PDA) with a touch screen. The present laboratory study was conducted to validate this PVT against a standard 10-min laptop PVT across 38 h of total sleep deprivation (TSD).

METHODS

Following a baseline sleep night, subjects underwent 38 h of TSD, during which they performed the PVT every hour, alternating between the two test platforms. The study concluded with a night of recovery sleep.

RESULTS

The primary outcome was the number of PVT lapses (reaction times > 500 ms). Both PVT platforms showed significant effects for the number of lapses across TSD test times involving an increase with time awake modulated by circadian rhythm. Laptop PVT lapses across test times exhibited a large effect size (f2 = 0.36), whereas PDA PVT lapses exhibited a medium effect size (f2 = 0.17). The laptop PVT showed a significant effect for the number of false starts during TSD similar to the temporal profile of lapses, while the PDA PVT had false starts throughout the TSD period.

DISCUSSION

The 5-min PDA PVT provided performance testing functionality and results comparable to the 10-min laptop PVT. The number of PDA PVT lapses tracked fatigue similarly to the laptop PVT lapses, albeit with smaller average ranges and effect sizes.