Fig. 6.

Schematic of a mechanism postulated to explain how sleep loss contributes to accidents. The top panel, copied from Fig. (5), depicts performance variability across a 10-minute interval at 60 hours of total sleep deprivation; extended bars represent lapses of attention. The middle panel shows a hypothetical pattern of changing cognitive demands over the 10-minute interval. The bottom panel displays the hypothetical impact of human error over the course of the 10-minute interval. Accidents are most likely to occur when lapses of attention line up temporally with high performance demands as well as substantial consequences of error, as where illustrated by the dotted gray line. Thus, accidents related to sleep loss are unusual (rare), but typically profound (catastrophic). The schematic can be adapted for specific operational settings by replacing the middle panel with one or more particular, temporally varying safety risk (e.g., for road transportation: traffic density, weather conditions, etc.). Figure adapted from [41] with permission.