Decision-making After Sleep Restriction

• high-density electroencephalography (hdEEG) marker of sleep pressure[ Time Frame: assessed during all sleep restriction nights in comparison to baseline values ]
  Slow wave activity (SWA) assessed by hd-EEG with 128 electrodes
• brain metabolites[ Time Frame: before to after 7 nights of sleep restriction with and without acoustic stimulation ]
  Glutamate and gamma-aminobutyric acid (GABA) concentration in the right prefrontal Cortex assessed by magnetic resonance (MR) spectroscopy
• vigilance measures[ Time Frame: before to after 7 nights of sleep restriction with and without acoustic stimulation ]
  Performance impairments in the psychomotor-vigilance task
• deception willingness[ Time Frame: before to after 7 nights of sleep restriction with and without acoustic stimulation ]
  deception willingness measured by the willingness to deception of outcome in a card game with binary outcome (win and loss)
• Motor inhibitory control performance[ Time Frame: before to after 7 nights of sleep restriction with and without acoustic stimulation ]
  inhibitory control performance measured by the stop-signal-task.
• confidence[ Time Frame: before to after 7 nights of sleep restriction with and without acoustic stimulation ]
  overconfidence measured by an incentivised procedure that elicits the certainity equivalent of a bet based on Performance in a quiz (cf. Murad et al. 2016 J Risk Uncertain)
• overconfidence[ Time Frame: before to after 7 nights of sleep restriction with and without acoustic stimulation ]
  overconfidence measured by an incentivised procedure that elicits the certainity equivalent of a bet based on Performance in a quiz (cf. Murad et al. 2016 J Risk Uncertain)
• impulsivity[ Time Frame: before to after 7 nights of sleep restriction with and without acoustic stimulation ]
  impulsivity as measured by an intertemporal choice Task.
• Ocular inhibitory control performance[ Time Frame: before to after 7 nights of sleep restriction with and without acoustic stimulation ]
  Ocular inhibitory control Performance measured by the Anti-Saccade Task.
• Effort in inhibitory control performance[ Time Frame: before to after 7 nights of sleep restriction with and without acoustic stimulation ]
  Pupil response (i.e. dilation) during a simple Go/No-Go Task.
• Excessive daytime sleepiness[ Time Frame: before to after 7 nights of sleep restriction with and without acoustic stimulation ]
  Excessive daytime sleepiness assessed by the Epworth sleepiness scale and the Stanford Sleepiness Scale.

The aim of this project is to investigate whether enhancing sleep intensity locally in the prefrontal cortex (PFC) can counteract a deterioration of cognitive control and therefore the previously described increase in risk seeking during chronic sleep restriction. To this end, a controlled, counter-balanced study, consisting of two weeks of sleep restriction will be performed. During one of the sleep restriction weeks, sleep intensity in the PFC will be non-invasively enhanced by acoustic stimulation of slow waves during sleep.

• Behavioral: Sleep restriction
  Time in bed will be restricted to 5 hours per night for 7 nights.
• Other: Acoustic stimulation
  Brief tones will be presented time-locked to ongoing slow waves during deep sleep.

• Sham Comparator: Sleep restriction without acoustic stimulation
• Experimental: Sleep restriction with acoustic stimulation