The obstructive sleep apnea syndrome (OSAS) involves recurrent sleep-related upper airways (UA) collapse. UA mechanical properties and neural control are altered, imposing a mechanical load on inspiration. UA collapse does not occur during wakefulness, hence arousal-dependent compensation. Experimental inspiratory loading in normal subjects elicits respiratory-related cortical activity during wakefulness. The objective of this study is to test whether awake OSAS patients would exhibit a similar cortical activity. Whether or not such cortical compensatory mechanisms have cognitive consequences would be also analyze.

Inclusion criteria :

1. OSAS patients

   • severe OSAS with an Apnea-Hypopnea Index (AHI) > 30/h
   • without CPAP treatment

2. Non-OSAS patients

   • absence of OSAS (AHI < 15/h and absence of excessive daytime sleepiness with Epworth score <11)

Non-inclusion criteria :

• < 18 years old
• >75 years old
• left-handed
• BMI> 40 kg/m²
• another sleep disorder
• central component of sleep apnea syndrome (central apnea index> 5 / h)
• current or past neurological pathology
• respiratory pathology (obstructive ventilatory disorder, restrictive ventilatory disorder, hypercapnia)
• MRI contraindication (metallic foreign body, claustrophobia, pregnant woman, etc.)
• taking drugs that can modify the BOLD signal on MRI (psychotropic drugs, vasodilators, vasoconstrictors, etc.),
• uncorrected sensory impairment (vision or hearing)
• protected by law.

Exclusion criteria :

• pregnant woman according to the positive beta-hCG test result

• left-handed following the laterality questionnaire

• MINI results showing:

  • a current mood episode
  • a current disorder of the use of psychoactive substances or in the last 6 months (excluding tobacco)
  • an eating disorder
  • a diagnosis of bipolar disorder, current or past schizophrenia