Le mercredi 19 mars 2025, Monsieur Paradeisios BOULAKIS, titulaire d'un d’un Master of science in psychology, specialisation cognitive neuroscience (Université de Maastricht) 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 Madame Athina DEMERTZI.

Cette épreuve consistera en la défense publique d'une thèse intitulée : «Where was my mind? Neurophysiological correlates of mind-blanking». 

Le jury sera composé de :

Steve MAJERUS (Président), David STAWARCZYK (Secrétaire),  Arnaud D'ARGEMBEAU, Athina DEMERTZI, Theodoros KARAPANAGIOTIDIS (Sussex Univ.), Wim NOTEBAERT (UGent), Christophe PHILLIPS, Christina SCHMIDT.

Résumé de la thèse

Our stream of thought consists of content-rich mental states, but people sometimes report an “absence of thoughts,” termed mind-blanking (MB). The emergence of this no-thought state remains unclear. This thesis explores MB through various neurophysiological methods during task-engagement and rest, linking it to brain-body structures. In study 1, we examined BOLD activity to differentiate which brain regions are implicated in MB during rest. In study 2, we examined brain-body interactions under different arousal conditions to correlate MB to different brain-body states. Finally, in study 3, we utilized dynamical fMRI connectivity during an attentional task to map MB to time-resolved brain activity. We show that MB is associated with a pattern of whole-brain deactivations. When contrasted to mental states with reportable content, MB correlates with frontal and parietal deactivations. Additionally, we found that MB is an arousal-mediated state, as MB propensity increases in low and high arousal. When we attempted to decode MB, optimal performance was attained when considering both brain and body activity. Finally, we show that sleepiness is associated increased inter-areal connectivity, while MB is associated with a complex anti-correlated brain pattern. Overall, this thesis shows that MB is associated with states of alerted cortical and physiological arousal.