Examining belief and confidence in schizophrenia

Abstract

Background People with psychoses often report fixed, delusional beliefs that are sustained even in the presence of unequivocal contrary evidence. Such delusional beliefs are the result of integrating new and old evidence inappropriately in forming a cognitive model. We propose and test a cognitive model of belief formation using experimental data from an interactive “Rock Paper Scissors” game. Methods Participants (33 controls and 27 people with schizophrenia) played a competitive, time-pressured interactive two-player game (Rock, Paper, Scissors). Participant’s behavior was modeled by a generative computational model using leaky-integrator and temporal difference methods. This model describes how new and old evidence is integrated to form both a playing strategy to beat the opponent and provide a mechanism for reporting confidence in one’s playing strategy to win against the opponent Results People with schizophrenia fail to appropriately model their opponent’s play despite consistent (rather than random) patterns that can be exploited in the simulated opponent’s play. This is manifest as a failure to weigh existing evidence appropriately against new evidence. Further, participants with schizophrenia show a ‘jumping to conclusions’ bias, reporting successful discovery of a winning strategy with insufficient evidence. Conclusions The model presented suggests two tentative mechanisms in delusional belief formation – i) one for modeling patterns in other’s behavior, where people with schizophrenia fail to use old evidence appropriately and ii) a meta-cognitive mechanism for ‘confidence’ in such beliefs where people with schizophrenia overweight recent reward history in deciding on the value of beliefs about the opponent.

The dysconnection hypothesis (2016)

“…The most promising candidate for explaining false inference in schizophrenia is the neuronal encoding of uncertainty (Averbeck et al, 2011). Psychologically, this corresponds to the salience or precision afforded to sensory evidence (Joyce et al, 2013); while physiologically it is thought to be encoded by the gain or excitability of principal (e.g., superficial pyramidal) cells. This resonates with concepts like aberrant salience (Kapur, 2003), while explicitly implicating modulatory neurotransmission in pathophysiology.…”

The Importance of Sensory Processing in Mental Health: A Proposed Addition to the Research Domain Criteria (RDoC) and Suggestions for RDoC 2.0

“…Some researchers argue that in addition to contributing to motor symptoms, abnormalities in proprioception may also lead to difficulty in self-awareness and agency, contributing to the core symptoms associated with schizophrenia (Arnfred et al, 2015). This body of work links sensory sensitivity — in the sense of failures of sensory attenuation — to schizophrenia and misattribution of agency (e.g., Shergill et al, 2005; Joyce et al, 2013). This again emphasizes the importance of sensation in higher cognitive functions and associated psychopathology and the relevance of a sensory processing domain within the RDoC framework.…”

Comprehensive review: Computational modelling of schizophrenia

“…The Bayesian brain hypothesis of schizophrenia has received relatively little empirical testing and validation, with the exception of studies investigating illusions (Crawford et al, 2010;Dima et al, 2010Dima et al, , 2009Horton and Silverstein, 2011;Keane et al, 2013;Silverstein and Keane, 2011a,b;Tschacher et al, 2006;Williams et al, 2010) or explicit statistical learning (Averbeck et al, 2011;Evans et al, 2012;Freeman et al, 2008Freeman et al, , 2014Huq et al, 1988;Joyce et al, 2013;Speechley et al, 2010). Such studies however, tend to investigate either illusions or learning in isolation (i.e.…”