3-min version of s2P is a valid tool for differentiating alert from sleepy states and is as sensitive as the Psycho Vigilance Test for tracking fatigue-related changes during extended wakefulness and sleep loss.
Jean Francois Brunet etal. Validation of sleep-2-Peak: A smartphone application that can detect fatigue-related changes in reaction times during sleep deprivation. Behav Res (2017) 49:1460–1469
