Belief Formation

Example Projects

Prediction-error learning and belief formation

Richard Morris, Melissa Green and Mike Le Pelley 

This project uses associative learning paradigms to understand belief formation in psychosis. Normally, our beliefs change in order to reduce the difference between our expectations and our observations. Delusions are traditionally defined as false beliefs that do not match reality and persist despite contrary evidence, yet why they occur is not well understood. Prediction error minimisation offers a framework to understand how delusions arise and why they persist. Formally, prediction-error minimisation relies on increasing (+∆) and decreasing (-∆) beliefs to match our observations. Our hypothesis is that dysfunctions in either the positive (+∆) or negative changes (-∆) (or both), that drive normal belief formation, cause aberrant belief formation (e.g., delusions) in psychosis. We have tested how beliefs are formed among people with schizophrenia as they learn to predict events. By fitting a prediction-error model to patients’ choices as their beliefs are formed, we have found smaller negative changes (-∆) occurred in people with schizophrenia, while the positive changes (+∆) appeared normal. This resulted in distorted beliefs that were not re-evaluated in the face of counter-evidence; highlighting the consequences for belief formation while also offering an explanation for the persistence of delusions. Finally, the size of the impairment was positively correlated with the severity of negative symptoms, indicating a relationship with schizophrenia disease pathology. Overall, our investigations reveal belief formation in psychosis is disrupted due to a specific deficit in learning from negative predictionerrors (-∆) that explains the formation of psychotic delusions, as well as their persistent nature.

Mechanisms of vision processing, multisensory integration and social perception in schizophrenia

Kiley Seymour, Nathan Caruana, Robyn Langdon and Gillian Rhodes, with Colin Clifford (The University of New South Wales) and Colin Palmer (The University of New South Wales) 

This research project examines the various levels at which processing of socially relevant information may be disrupted in schizophrenia, which in turn, may lead to poor social functioning and socially-themed delusional beliefs. One series of studies has been examining the very early unconscious stages of face processing using a novel ‘invisible stimulus’ paradigm adapted from vision science. The data suggests an impairment at a subcortical stage in schizophrenia. The human visual system typically detects socially relevant information more rapidly, such as upright faces and fearful faces, as compared to inverted faces and happy faces. This may not be the case for people with schizophrenia. We have also examined perceptual biases in judging the gender of a face. Healthy adults exhibit a bias to perceive ambiguous faces as male, whereas early data suggest that this bias may be even more pronounced in patients with schizophrenia, which could result in a hypersensitivity to perceive more threatening stimuli. Other experiments build upon our more basic vision research using visual illusion paradigms to investigate how patients with schizophrenia integrate information. The findings suggest that these individuals have difficulty integrating sensory cues such as head orientation and early sensory levels of eye-gaze processing. These studies complement our fMRI research testing the integrity of neural mechanisms underlying the perception of gaze information in these same patients.

Using functional brain imaging and transcranial magnetic stimulation

Kiley Seymour, Nathan Caruana, Susan Wardle, Blake Johnson, David Kaplan, Robyn Langdon, Max Coltheart, Amanda Barnier, Rochelle Cox, Paul Sowman, Devin Terhune, Vince Polito, James Moore, Simmy Poonian, with Gillian Rhodes, Colin Clifford (The University of New South Wales) and Colin Palmer (The University of New South Wales) 

This research stream investigates the functional brain disruptions associated with psychotic experiences in schizophrenia, and builds upon our previous successes using hypnotic suggestions to produce temporary, reversible ‘virtual patients’. Seymour, Wardle and colleagues are testing a leading hypothesis based on previous post-mortem, genetics, and animal model studies. The hypothesis is that dysfunction of GABA-mediated contextual inhibition contributes to the aberrant psychotic experiences reported in schizophrenia. The project combines fMRI and approaches from vision science to understand gaze processing to probe GABA dysfunction non-invasively in patients. The aim is to examine how the reported cellular and molecular disruptions to the GABA system impact real-time cortical function in schizophrenia. In ‘prediction-error’ models of psychotic experiences (e.g., of alien control), Poonian and colleagues have been assessing an MEG paradigm to investigate how monitoring the predicted sensory consequences of intentional actions influences action control, and in turn a sense of personal agency, as well as how expectations about others’ intentional actions are reflected in brain activity. Both topics are fundamental to understanding attributions of causality and how we distinguish between ourselves and others. Coltheart is leading a project using transcranial magnetic stimulation to examine the effects on hypnotic suggestibility of temporarily disrupting activity of the right dorsolateral prefrontal cortex, while Terhune and colleagues are using MEG with highly hypnotisable subjects and controls to record resting state and task-related neural activity during the ‘Metacognition of Agency Task’ to investigate the neurocognitive basis of hypnotic suggestibility and disrupted sense of agency in the hypnotic state.

Monitoring our actions and bodies

Vince Polito, Regine Zopf, Stephen Pritchard, David Kaplan, Mark Williams, James Moore and Glenn Carruthers

This project aims to understand how we develop a sense of controlling our actions and thoughts (sense of agency), how we recognise the distinction between our own bodies and other objects in space (sense of body ownership), and feel a sense of being a self, situated within an environment (sense of presence). We seek to understand how these different senses of self-representation vary in different contexts and in different clinical disorders, such as anorexia and schizophrenia, and we aim to develop a unifying theory that will clarify the interrelationships between these various senses of being a self. Researchers across domains currently emphasise different aspects of self-representation in different ways. For example, it is very common for hypnosis researchers to discuss altered sense of agency but far less common for them to discuss participants’ sense of owning their own body during hypnosis. Similarly, computer scientists frequently discuss the sense of presence in virtual reality without directly addressing questions of agency or body ownership. We are developing a new scale to better clarify the relationships between agency, body ownership and presence and to improve the ability of researchers and clinicians to monitor self-reported changes affecting different forms of self-representation in different contexts. We are also using virtual reality to study alterations to sense of agency, body ownership and presence. Specifically, we have investigated what kinds of multisensory cues (synchrony of touch, visual body form and body position) are important for self-representations and we have considered what implications this research has for the design and applied use of virtual reality. Our research goal is to understand the extent to which individual differences in self representations relate to individual differences in the processing of different self-representation cues, and how self-representations differ in clinical disorders such as schizophrenia and anorexia nervosa.

Society and belief

Colin Klein, Vince Polito, Mariia Kaliuzhna, Rochelle Cox, Max Coltheart, Robyn Langdon, Ryan McKay and Robert Ross 

This broad research stream goes beyond a focus on clinically deluded individuals to study the spectrum of strongly-held beliefs seen in the general community, including the emotional, social and cultural factors that influence these beliefs, and their social consequences. Klein has been leading a cross-disciplinary project that brings together philosophers, cognitive scientists and linguists to use linguistic analyses of online forums to investigate conspiracy theories. Conspiracy theories can have major negative societal consequences, and their spread is facilitated by online forums and other forms of social media, yet scientific investigation to date has been largely limited to undergraduate populations and has relied on self-report inventories. We are advancing this field by identifying the social, linguistic, and psychometric factors that distinguish active participants in conspiracy forums. In other work, Kaliuzhna has been investigating the internal consistencies of people’s ‘just-world beliefs’. These are beliefs in a cosmic moral balance (e.g., ‘You reap what you sow’; ‘What goes around comes around’; ‘You get what you deserve’). McKay and Ross and their colleagues have been focusing, instead, on traditional religious beliefs with the aim of developing an ‘affective science of religious belief ’. They have run cross-cultural and experimental studies to investigate the relationships between negative life events and religious beliefs, and have been investigating the malleability of people’s religious beliefs and attitudes. Ross and his colleagues have also reported a meta-analysis of empirical studies of reasoning styles in atheists, agnostics and religious believers, while in other related work, McKay and his PhD student, Ben Tappin, have reviewed evidence of moral prejudice against atheists. This research may have broad implications (e.g., they are examining whether witnesses in court cases who swear on the bible are perceived as more credible than those who take a secular affirmation).

Treatment for delusions

Ryan Balzan and Steffen Moritz 

This year, we have been evaluating an individually administered version of ‘metacognitive therapy’ (MCT+). The original MCT program was developed to reduce delusional severity in psychotic patients by targeting the cognitive and social biases that are thought to underlie the formation and maintenance of delusional beliefs. It comprises a series of instructor-led group intervention modules targeting attribution biases, jumping-toconclusions, belief inflexibility, overconfidence in errors, theory-of-mind deficits, and depressive cognitive schemata, as well as considering stigma and low selfesteem. The program attempts to raise (metacognitive) awareness of one’s own thinking biases, thereby planting ‘seeds of doubt’, and encouraging critical reflection. Large randomised control trials and a recent metaanalysis indicate MCT is effective in reducing delusional severity, including at 3-years post-treatment. The new MCT+ approach combines the ‘process-oriented’ approach of the original MCT group-training with an initial clinical interview to evaluate a patient’s medical history and current symptoms so as to incorporate elements of individually tailored cognitive-behavioural therapy for psychosis (CBTp) and relate general information from the MCT modules to the specific experiences/symptoms of each patient. Discussing a patient’s symptoms within the context of cognitive biases is a gentler approach, and may be perceived by the patient as less threatening than a more direct CBTp ‘front door’ approach. This individualised approach also allows for a greater range of therapeutic strategies, such as establishing specific therapy goals with each patient. Although clinical trials of MCT+ are ongoing, preliminary data analysis suggests participants with schizophrenia allocated to a MCT+ program show greater reduction in delusions relative to controls receiving cognitive remediation. These results have important theoretical implications for the cognitive neuropsychiatric approach to studying delusions, strengthen empirical evidence for the efficacy of psychological interventions for psychosis, and offer clinicians more options to select the most appropriate intervention for their patient.