The investigators examine changes in decision making, vigilance and cortical excitability in healthy male subjects undergoing total acute sleep deprivation (40 hours) on the one hand, and chronic partial sleep restriction (7 nights with 5 instead of 8 hours in bed per night) on the other hand, in a cross over controlled manner. The investigators hypothesize that total sleep deprivation, as well as partial sleep restriction lead to impairments in decision making and vigilance, and enhanced cortical excitability.
Beside these three primary outcomes, the investigators also assess changes in sleep by EEG, dim light melatonin onset, skin temperature, subjective mood and sleepiness, working memory, and also collect saliva samples.
Inclusion Criteria:
Exclusion Criteria:
Contraindications on ethical grounds
Clinically significant concomitant disease states (e.g., renal failure, hepatic dysfunction, cardiovascular disease, etc)
Known or suspected non-compliance, drug or alcohol abuse (> 5dl wine/ >1l beer daily)
Regular medication intake
Enrolment into a clinical trial within last 4 weeks
History of seizure or a family history of epilepsy
Diseases or lesions of the nervous system (acute or residual included neurological and psychiatric diseases)
History of any moderate or heavy head trauma
Sleep disorders (e.g. Insomnia, sleep apnea, restless leg syndrome, narcolepsy, etc.)
Sleep complaints in general or EDS
Irregular sleep-wake rhythm (e.g. shift working)
Long (> 9 hours per night) or short sleepers (< 7hours per night)
Sleep efficiency ≤ 80%
Travelling with time lag less than 1 month ago (or planning to do so within 1 month prior to the study)
Body Mass Index < 19 or > 30 kg/m2
Student of one of the following subjects: Mathematics, Physics, Computer Science, Economics, or Psychology (since students of these subjects have profound knowledge of probability calculations, which could interfere with our measurements in decision making)
The following additional exclusion criteria apply only to subjects with TMS sessions
History of frequent and/or heavy headache respectively migraine
History of claustrophobia
Hearing disorder
Magnetic Resonance Imaging (MRI) contraindication (such as pacemaker implanted pumps, shrapnel, etc.; full MRI screening form will be filled out - see -Entrance questionnaires)
No clear TMS evoked potential in the target area during the screening assessment
These subjects will be invited to participate in the study with no TMS sessions, the other protocol being identical