The Psychomotor Vigilance Test (PVT)

First described by Dinges & Powell (1985) Simple reaction time to a visual stimulus Collected over 5-10 minutes Fatigue indicated by "lapses" (long RTs)

Dinges, D. F., and Powell, J. W. (1985). Microcomputer analyses of performance on a portable, simple visual RT task during sustained operations. Behav. Res. Meth. Instr. Com., vol. 16, pp. 652-5.