Impact of experimentally manipulated sleep on adolescent simulated driving

Sleep restriction (SR) impairs adolescents' attention, which could contribute to high rates of driving crashes. Here, we examine the impact of experimental SR on adolescent drivers, considering whether that impact is moderated by the nature of the drive (urban/suburban vs. rural) or how vulnerable each adolescent is to attentional decline after SR.

A total of 17 healthy 16-18-year-old licensed drivers completed two five-night sleep conditions: SR (6.5 h in bed) versus extended sleep (ES; 10 h in bed) in counterbalanced order. After each, participants completed rural and urban/suburban courses in a driving simulator, and parents rated participants' attention in day-to-day settings. Vulnerability to SR was computed as cross-condition change in parent ratings. Dependent variables included standard deviation (SD) of lateral lane position (SDLP), mean speed, SD of speed, and crashes. Multivariate models examined the main and interaction effects of sleep condition, driving environment, and vulnerability to SR, covarying for years licensed.

Although the effects for the other outcomes were nonsignificant, there were three-way interactions (sleep × drive × vulnerability) for mean speed and SDLP (p <0.02). During the rural drive, adolescents had less consistent lateral vehicle control in SR than ES, despite slower driving among those reported to be vulnerable to SR. During the urban/suburban drive, SR worsened SDLP only among adolescents reported to be vulnerable to SR.

These preliminary findings suggest that even a moderate degree of SR may be a modifiable contributor to adolescent driving problems for some. This impact is widely present during monotonous rural drives and in a subgroup during interesting urban/suburban drives.