Alerting, Orienting and Executive Control: The effects of sleep deprivation

Sleep deprivation has been shown to alter attentional functions, like sustaining an alert state over a period of time (vigilance or tonic alerting). However, the effects of sleep loss on both orienting and executive control are not still clear, and no study has assessed whether sleep deprivation might affect the relation among these three attentional abilities. In this study we used the Attentional Network Test (ANT) in order to investigate the efficiency of the three networks: alerting, orienting and executive control. Eighteen right-handed male subjects participated to the experiment, which took place on two consecutive days. On the first day, in order to evaluate baseline condition, the subjects performed the ANT; on the second day, during 24 h of sleep loss, the same task was performed two times, at 5.00 p.m and at 4.00 a.m. Results showed an overall slowing of reaction time in the nocturnal session, indicating a decrease of vigilance. The orienting network influenced the executive function network in a positive way (the flanker effect was smaller for spatial cue than for the other type of cues). However, results did not confirm an effect of sleep deprivation on both executive control and orienting systems, suggesting the independence between the tonic component of the alerting and the other two attentional systems.