Le mardi 5 novembre 2024, Madame Benedetta CECCONI, titulaire d’un Master of sciences in cognitive science (Università degli Study di Trento) et d’un Certificat de formation à la recherche en sciences biomédicales et pharmaceutiques, présentera l'examen en vue de l'obtention du grade de Doctorat en sciences biomédicales et pharmaceutiques, sous la direction de Monsieur Steven LAUREYS et de Madame Jitka ANNEN.

Cette épreuve consistera en la défense publique d'une thèse intitulée :  "Cerebral characterization of sensory gating in disconnected dreaming states during REM sleep and propofol sedatison using hd-EEG and fMRI".

Le jury sera composé de :

Vincent BONHOMME (Président), Christina SCHMIDT (Secrétaire), Thomas ANDRILLON (Inst. Cerveau Paris), Jitka ANNEN, Marianna BEVOVA (Univ. Luxembourg), Steven LAUREYS, Didier LEDOUX, Charline URBAIN (ULB).

Résumé de la thèse :

Consciousness, defined as subjective experience, can detach from the external environment, leading to sensory disconnection while preserving awareness. The neural mechanisms of this phenomenon are poorly understood due to challenges in distinguishing connected consciousness (CC) from disconnected consciousness (DC). Previous studies comparing wakefulness to sleep or anesthesia were limited by inherent physiological differences.

This study utilized auditory stimulation during REM sleep and propofol sedation, followed by awakenings to gather subjective reports on participants’ consciousness and sound perception. Using an oddball paradigm, brain activity was recorded with high-density EEG during REM sleep and fMRI during propofol sedation. We compared brain activity of CC and DC participants to investigate the mechanisms of sensory disconnection.

EEG analyses revealed distinct differences in event-related potential components between CC and DC, indicating more complex processing in CC. Dynamic Causal Modeling indicated reduced connectivity in DC. During propofol sedation, paradoxical activation increases were noted in DC compared to CC. This study provides evidence that differential sound processing occurs between CC and DC, revealing distinct neural signatures of sensory disconnection during REM sleep and anesthesia.