Investigating the link between dopamine and the neurocomputational mechanisms of auditory verbal hallucinations
Supervisors:
Dr Filippo Queirazza, School of Health and Wellbeing
Prof Marios Philiastides, School of Psychology & Neuroscience
Dr Joana Carvalheiro, School of Psychology & Neuroscience
Summary:
Auditory verbal hallucinations (AVH) are the hallmark feature of psychosis. AVH have been linked to excessive dopamine in the striatum, and their treatment of choice is antipsychotic medications, which reduce dopamine transmission in the brain. Yet, a comprehensive mechanistic understanding of the link between dopamine and AVH has been elusive.
While perceptual decisions are primarily influenced by sensory evidence, our sensory system also leverages prior knowledge to make optimal perceptual judgements. Such perceptual priors can bias perceptual inference and, under certain abnormal conditions, even give rise to perceptual disturbances including AVH. Preliminary empirical evidence has linked dopamine to EEG and computational signatures of perceptual decision-making. In this project we plan to use advanced computational and neuroimaging (i.e., EEG) analysis techniques to characterize the mechanisms underpinning auditory perceptual biases and ensuing AVH in both healthy subjects. Moreover, we aim to leverage pharmacological manipulations of dopamine in healthy subjects to establish a causal link between dopamine and perceptual biases, thus bridging the gap between AVH phenomenology and neurobiology.