Figure 1.

Study protocol. One week before the experimental day, the screening of volunteers through questionnaires (MEQ = Horne and Ostberg Morningness-Eveningness Questionnaire; ESS = Epworth Sleepiness Scale; PSQI = Pittsburgh Sleep Quality Index and BIS-11 = Barratt Impulsivity Scale) and the actigraphy recordings were initiated. On Day 6, volunteers were assigned to one of three groups: control, in which participants initiated sleep and woke up at their habitual time; morning restriction, in which volunteers woke up approximately three hours earlier than usual on the day of the experiment; evening restriction, in which volunteers initiated sleep approximately three hours later than usual in the experimental night (the white bars represent wakefulness and the black bars represent the sleep period). On the experimental day, they filled out the Karolinska Sleepiness Scale (KSS) and performed three behavioral tests: Stroop Test, Go-NoGo and Iowa Gambling Task (IGT).