Chronic sleep loss and risk-taking behavior: Does the origin of sleep loss matter?

Background: Many adolescents and young adults get insufficient sleep. A link between sleep loss and risk-taking behavior has been consistently found in the literature, but surprisingly, the role played by the origin of sleep loss in this link has never been investigated. Sleep loss can be voluntary (instead of sleeping, a significant amount of time is devoted to other activities) or involuntary (caused by a sleep disorder, for example, insomnia). The aim of this research was to investigate whether both types of sleep loss are associated to the same extent with risky behavior. Participants: Five hundred thirty-six university students between 19 and 25 years old participated in this study. Three groups were selected: participants with voluntary sleep loss, participants with insomnia, and normal sleepers. Methods: We assessed risk-taking behavior in virtual driving situations, as well as drinking habits in terms of quantity and frequency. To further explore the differences between the groups, we also measured sensation seeking, a personality trait related to risk-taking behavior. Results: Compared to participants with insomnia and normal sleepers, participants with voluntary sleep loss take more risks in dangerous driving situations, drink more alcohol, and have higher disinhibition scores on the Sensation-Seeking Scale. On the other hand, no such differences were found between participants with insomnia and normal sleepers, suggesting that sleep loss is not always associated with risk taking. Conclusions: Whether sleep loss is associated with risk-taking behavior or not could depend on the origin of sleep loss and the underlying personality traits.

Eveningness is associated with higher risk-taking in dangerous driving situations.

Inclination toward eveningness is often associated with risky behavior. But the existing studies are scarce, inconsistent and usually limited to self-reported measures. We sought to investigate in young adults whether morningness-eveningness is associated with risky behavior in dangerous driving situations, with self-reported drunk driving and with alcohol consumption. Results show that, indeed, inclination toward eveningness is associated with these risky behaviors. We also demonstrate a link between morningness-eveningness and sensation seeking. Therefore, young adults with a tendency toward eveningness might be more at risk to face negative consequences of alcohol abuse or to be involved in a road accident.

[The elderly driver's perception of risk: do older drivers still express comparative optimism? ]. / Personnes âgées et perception des risques en matière de conduite automobile : les conducteurs âgés manifestent-ils encore de l'optimisme comparatif?

People frequently express comparative optimism ; that is, they believe they are less likely than average to experience negative events. The aim of the present study is, first, to observe whether people of more than 65 years are still optimists when they evaluate driving-related risks; and second, to test the assumption that older drivers show less optimism when they compare themselves with average-age drivers than when they compare themselves with same-age drivers. Our results reveal that drivers of more than 65 years do, indeed, express comparative optimism, but, contrary to our expectation, only in a limited number of cases does the age of the comparison target appear to have an effect. These results are particularly discussed in terms of self-image enhancement.

Influence of age, speed and duration of monotonous driving task in traffic on the driver's useful visual field.

Recent research has shown that the useful visual field deteriorates in simulated car driving when the latter can induce a decrease in the level of activation. The first aim of this study was to verify if the same phenomenon occurs when driving is performed in a simulated road traffic situation. The second aim was to discover if this field also deteriorates as a function of the driver's age and of the vehicle's speed. Nine young drivers (from 22 to 34 years) and nine older drivers (from 46 to 59 years) followed a vehicle in road traffic during two two-hour sessions. The car-following task involved driving at 90 km.h(-1) (speed limit on road in France) in one session and at 130 km.h(-1) (speed limit on motorway in France) in the other session. While following the vehicle, the driver had to detect the changes in colour of a luminous signal located in the central part of his/her visual field and a visual signal that appeared at different eccentricities on the rear lights of the vehicles in the traffic. The analysis of the data indicates that the useful visual field deteriorates with the prolongation of the monotonous simulated driving task, with the driver's age and with the vehicle's speed. The results are discussed in terms of general interference and tunnel vision.