Speaker :  

Dr Graham Murray
Visiting Academic 
Institute for Molecular Bioscience, The University of Queensland

Title: "From dopamine to delusions: mechanisms of psychotic symptom formation"

Abstract: What are the mental processes that underpin the pathogenesis of psychotic symptoms? In this talk I will focus on three relevant processes that have been proposed to lead, when dysfunctional, to psychosis: learning, probabilistic reasoning and predictive coding. I will describe recent fMRI studies demonstrating abnormal cortical and subcortical brain activation in psychosis during reinforcement learning. I will introduce the concepts of prediction error, and precision-weighted prediction error, and show recent evidence from my group that precision-weighted prediction error signals are encoded in the human brain, are associated with improved learning, are modulated by dopamine, are abnormal in psychosis, and predict psychotic symptoms in patients and schizotypal traits in health. I will describe studies investigating the role of information sampling in probabilistic reasoning, and discuss the role of generalised cognitive impairment or specific cognitive deficits (in evaluating the cost of information sampling) underpinning the “jumping to conclusions” bias in schizophrenia. I will then address predictive coding in psychosis, and how alterations in the balance between prior expectations and sensory evidence may account for faulty perceptions and inferences leading to psychosis. I will discuss changes in how cognitive and perceptual priors influence decision making during the emergence of psychosis. I will close by considering how mechanistic studies of the cognitive pathophysiology of psychosis are relevant for treatment development.

 

About Neuroscience Seminars

Neuroscience seminars at the QBI play a major role in the advancement of neuroscience in the Asia-Pacific region. The primary goal of these seminars is to promote excellence in neuroscience through the exchange of ideas, establishing new collaborations and augmenting partnerships already in place.

The scheduled QBI Neuroscience Seminar series are held on Wednesdays from 11am-12pm in the Level 7 Auditorium of the Queensland Brain Institute, Building 79, St Lucia Campus, The University of Queensland. Additional seminars may be held at other times as listed below.

 

Neuroscience Seminars archive 2005-2018