Positive symptoms in schizophrenia include a combination of hallucinations, delusions and disorganized thinking. In a forced-choice task with varying levels of sensory evidence and prior information, participants' confidence was best captured by a model with different degrees of circular inference. Circular inference refers to a corruption of sensory data by prior information and vice versa, leading us to 'see what we expect' (through descending loops), to 'expect what we see' (through ascending loops) or both. Ascending loops were stronger for patients than controls and correlated with the severity of positive symptoms while descending loops correlated with the severity of negative symptoms. In addition, both loops correlated with the level of disorganized symptoms. The findings suggest that circular inference might mediate the clinical manifestations of schizophrenia.

Renaud Jardri is a Professor of Child & Adolescent Psychiatry at the Lille University School of Medicine, and Associate Faculty in the Group for Neural Theory, INSERM U-960, at the Ecole Normale Supérieure Paris. Renaud obtained his MD in 2007 and his PhD in Neuroscience in 2010 at the University of Lille. He did a postdoctoral fellowship from 2009 to 2011 with Sophie Deneve at the Ecole Normale Superieur in Paris. His main research interests are the exploration of the underlying neural mechanisms of hallucinations in children, adolescents and adults.

• Date: 12/6/19
• Time: 3:30 PM CET
• Location: PUK Zurich, H108
• Host: Philipp Homan