Thesis defense : Martin ROUY

Composition du jury :
Nathan FAIVRE, CHARGE DE RECHERCHE, CNRS, Directeur de thèse
Anne GIERSCH, DIRECTRICE DE RECHERCHE, INSERM, Rapporteure
Valérian CHAMBON, DIRECTEUR DE RECHERCHE, CNRS, Rapporteur
Catherine BORTOLON, MAITRESSE DE CONFERENCE, UGA, Examinatrice
Mircea POLOSAN, PROFESSEUR DES UNIVERSITES - PRATICIEN HOSPITALIER, UGA, Examinateur
Emmanuel BARBEAU, DIRECTEUR DE RECHERCHE, CNRS, Examinateur
Jérôme SACKUR, DIRECTEUR D'ETUDES, EHESS, invité
Céline Souchay, DIRECTRICE DE RECHERCHE, CNRS, invitée

During my thesis, we studied the metacognitive abilities of individuals with schizophrenia spectrum disorder using psychophysical and electrophysiological measures. My work had two parts: on the one hand, a fundamental part focused on the characterization of metacognitive abilities in these patients, thanks to a meta-analysis that highlighted the presence of methodological biases in the study of metacognition in patients with schizophrenia. Our work has shown that the protocols and measures used so far did not allow a clear distinction between cognitive and metacognitive components, with the consequence of overestimating the metacognitive deficit in this population. We corroborated this result by analyzing behavioral and electrophysiological data collected in patients performing a perceptual task adjusting cognitive performance to that of healthy volunteers, showing no alteration at the metacognitive level. In the continuity of these results, we have developed an original experimental paradigm that simultaneously quantified metacognition in perception and memory with the ambition of isolating the metacognitive component in our measurements and thus gaining internal validity; on the other hand, a more clinical part focused on remediation, by trying to replicate the effect of a metacognitive training from recent models based on psychophysics, a priori effective in a non-clinical population, and thus potentially exploitable in the case of metacognitive alterations. After controlling for confounding factors of motivational and/or instructional origin, we concluded that this metacognitive training was ineffective. In sum, my thesis has corroborated existing recommendations for the evaluation of metacognition in experimental psychology, in order to strengthen the validity of the measure. The methodological critique that has been made has the effect of downgrading the contribution of the metacognitive component - as captured by signal detection theory - in the symptomatology of schizophrenia; a necessary milestone for a reorientation of research efforts.