Jumping to conclusions and perceptions in early psychosis: relationship with delusional beliefs

The effects of base rate neglect on sequential belief updating and real-world beliefs

Base-rate neglect is a pervasive bias in judgment that is conceptualized as underweighting of prior information and can have serious consequences in real-world scenarios. This bias is thought to reflect variability in inferential processes but empirical support for a cohesive theory of base-rate neglect with sufficient explanatory power to account for longer-term and real-world beliefs is lacking. A Bayesian formalization of base-rate neglect in the context of sequential belief updating predicts that belief trajectories should exhibit dynamic patterns of dependence on the order in which evidence is presented and its consistency with prior beliefs. To test this, we developed a novel 'urn-and-beads' task that systematically manipulated the order of colored bead sequences and elicited beliefs via an incentive-compatible procedure. Our results in two independent online studies confirmed the predictions of the sequential base-rate neglect model: people exhibited beliefs that are more influenced by recent evidence and by evidence inconsistent with prior beliefs. We further found support for a noisy-sampling inference model whereby base-rate neglect results from rational discounting of noisy internal representations of prior beliefs. Finally, we found that model-derived indices of base-rate neglect-including noisier prior representation-correlated with propensity for unusual beliefs outside the laboratory. Our work supports the relevance of Bayesian accounts of sequential base-rate neglect to real-world beliefs and hints at strategies to minimize deleterious consequences of this pervasive bias.

Dopamine, cognitive biases and assessment of certainty: A neurocognitive model of delusions

This paper examines the evidence that delusions can be explained within the framework of a neurocognitive model of how the brain assesses certainty. Here, 'certainty' refers to both low-level interpretations of one's environment and high-level (conscious) appraisals of one's beliefs and experiences. A model is proposed explaining how the brain systems responsible for assigning certainty might dysfunction, contributing to the cause and maintenance of delusional beliefs. It is suggested that delusions arise through a combination of perturbed striatal dopamine and aberrant salience as well as cognitive biases such as the tendency to jump to conclusions (JTC) and hypersalience of evidence-hypothesis matches. The role of emotion, stress, trauma and sociocultural factors in forming and modifying delusions is also considered. Understanding the mechanisms involved in forming and maintaining delusions has important clinical implications, as interventions that improve cognitive flexibility (e.g. cognitive remediation therapy and mindfulness training) could potentially attenuate neurocognitive processes.

Association of the Jumping to Conclusions and Evidence Integration Biases With Delusions in Psychosis: A Detailed Meta-analysis

We completed a meta-analysis to investigate the relationship between delusions in psychosis and 4 cognitive biases: "jumping to conclusions" (JTC), the "bias against disconfirmatory evidence" (BADE), the "bias against confirmatory evidence" (BACE), and "liberal acceptance" (LA). Building on recent meta-analyses we compared more narrowly defined groups. We identified 35 JTC, 8 BADE, 7 BACE, and 6 LA studies for inclusion. Groups with schizophrenia who were currently experiencing delusions demonstrated greater JTC, BADE, BACE, and LA than groups with schizophrenia who were not currently experiencing delusions, who in turn demonstrated no more JTC than healthy control groups. Hence JTC, BADE, BACE, and LA co-vary with delusions in cross-sectional samples of people with schizophrenia. Groups who were experiencing delusions due to other psychiatric illnesses also demonstrated greater JTC than healthy controls, and equivalent JTC to groups with schizophrenia currently experiencing delusions. Hence JTC is associated with delusions across a range of diagnoses. Groups with other, non-delusional psychiatric illnesses demonstrated less JTC, BADE, BACE, and LA than groups with schizophrenia currently experiencing delusions, less JTC than groups experiencing delusions due to other diagnoses, and no more JTC, BADE, BACE, or LA than healthy control groups. Hence JTC, BADE, BACE, and LA were not associated with psychiatric illnesses in general. Our results indicate all 4 biases are associated with delusions specifically rather than merely with a diagnosis of schizophrenia or with being psychiatrically ill, consistent with the possibility that they contribute to delusional severity.

Reasoning in psychosis: risky but not necessarily hasty

INTRODUCTION

A liberal acceptance (LA) threshold for hypotheses has been put forward to explain the well-replicated "jumping to conclusions" (JTC) bias in psychosis, particularly in patients with paranoid symptoms. According to this account, schizophrenia patients rest their decisions on lower subjective probability estimates. The initial formulation of the LA account also predicts an absence of the JTC bias under high task ambiguity (i.e., if more than one response option surpasses the subjective acceptance threshold).

METHODS

Schizophrenia patients (n = 62) with current or former delusions and healthy controls (n = 30) were compared on six scenarios of a variant of the beads task paradigm. Decision-making was assessed under low and high task ambiguity. Along with decision judgments (optional), participants were required to provide probability estimates for each option in order to determine decision thresholds (i.e., the probability the individual deems sufficient for a decision).

RESULTS

In line with the LA account, schizophrenia patients showed a lowered decision threshold compared to controls (82% vs. 93%) which predicted both more errors and less draws to decisions. Group differences on thresholds were comparable across conditions. At the same time, patients did not show hasty decision-making, reflecting overall lowered probability estimates in patients.

CONCLUSIONS

Results confirm core predictions derived from the LA account. Our results may (partly) explain why hasty decision-making is sometimes aggravated and sometimes abolished in psychosis. The proneness to make risky decisions may contribute to the pathogenesis of psychosis. A revised LA account is put forward.

Evaluation of the 'Jumping to conclusions' bias in different subgroups of the at-risk mental state: from cognitive basic symptoms to UHR criteria

BACKGROUND

Patients with psychosis display the so-called 'Jumping to Conclusions' bias (JTC) - a tendency for hasty decision-making in probabilistic reasoning tasks. So far, only a few studies have evaluated the JTC bias in 'at-risk mental state' (ARMS) patients, specifically in ARMS samples fulfilling 'ultra-high risk' (UHR) criteria, thus not allowing for comparisons between different ARMS subgroups.

METHOD

In the framework of the PREVENT (secondary prevention of schizophrenia) study, a JTC task was applied to 188 patients either fulfilling UHR criteria or presenting with cognitive basic symptoms (BS). Similar data were available for 30 healthy control participants matched for age, gender, education and premorbid verbal intelligence. ARMS patients were identified by the Structured Interview for Prodromal Symptoms (SIPS) and the Schizophrenia Proneness Instrument - Adult Version (SPI-A).

RESULTS

The mean number of draws to decision (DTD) significantly differed between ARM -subgroups: UHR patients made significantly less draws to make a decision than ARMS patients with only cognitive BS. Furthermore, UHR patients tended to fulfil behavioural criteria for JTC more often than BS patients. In a secondary analysis, ARMS patients were much hastier in their decision-making than controls. In patients, DTD was moderately associated with positive and negative symptoms as well as disorganization and excitement.

CONCLUSIONS

Our data indicate an enhanced JTC bias in the UHR group compared to ARMS patients with only cognitive BS. This underscores the importance of reasoning deficits within cognitive theories of the developing psychosis. Interactions with the liability to psychotic transitions and therapeutic interventions should be unravelled in longitudinal studies.

Data Gathering Bias: Trait Vulnerability to Psychotic Symptoms?

Background

Jumping to conclusions (JTC) is associated with psychotic disorder and psychotic symptoms. If JTC represents a trait, the rate should be (i) increased in people with elevated levels of psychosis proneness such as individuals diagnosed with borderline personality disorder (BPD), and (ii) show a degree of stability over time.

Methods

The JTC rate was examined in 3 groups: patients with first episode psychosis (FEP), BPD patients and controls, using the Beads Task. PANSS, SIS-R and CAPE scales were used to assess positive psychotic symptoms. Four WAIS III subtests were used to assess IQ.

Results

A total of 61 FEP, 26 BPD and 150 controls were evaluated. 29 FEP were revaluated after one year. 44% of FEP (OR = 8.4, 95% CI: 3.9–17.9) displayed a JTC reasoning bias versus 19% of BPD (OR = 2.5, 95% CI: 0.8–7.8) and 9% of controls. JTC was not associated with level of psychotic symptoms or specifically delusionality across the different groups. Differences between FEP and controls were independent of sex, educational level, cannabis use and IQ. After one year, 47.8% of FEP with JTC at baseline again displayed JTC.

Conclusions

JTC in part reflects trait vulnerability to develop disorders with expression of psychotic symptoms.

Reduced activation in the ventral striatum during probabilistic decision-making in patients in an at-risk mental state

BACKGROUND

Patients with schizophrenia display metacognitive impairments, such as hasty decision-making during probabilistic reasoning - the "jumping to conclusion" bias (JTC). Our recent fMRI study revealed reduced activations in the right ventral striatum (VS) and the ventral tegmental area (VTA) to be associated with decision-making in patients with schizophrenia. It is unclear whether these functional alterations occur in the at-risk mental state (ARMS).

METHODS

We administered the classical beads task and fMRI among ARMS patients and healthy controls matched for age, sex, education and premorbid verbal intelligence. None of the ARMS patients was treated with antipsychotics. Both tasks request probabilistic decisions after a variable amount of stimuli. We evaluated activation during decision-making under certainty versus uncertainty and the process of final decision-making.

RESULTS

We included 24 AMRS patients and 24 controls in our study. Compared with controls, ARMS patients tended to draw fewer beads and showed significantly more JTC bias in the classical beads task, mirroring findings in patients with schizophrenia. During fMRI, ARMS patients did not demonstrate JTC bias on the behavioural level, but showed a significant hypoactivation in the right VS during the decision stage.

LIMITATIONS

Owing to the cross-sectional design of the study, results are constrained to a better insight into the neurobiology of risk constellations, but not prepsychotic stages. Nine of the ARMS patients were treated with antidepressants and/or lorazepam.

CONCLUSION

As in patients with schizophrenia, a striatal hypoactivation was found in ARMS patients. Confounding effects of antipsychotic medication can be excluded. Our findings indicate that error prediction signalling and reward anticipation may be linked to striatal dysfunction during prodromal stages and should be examined for their utility in predicting transition risk.

Jumping to delusions in early psychosis

INTRODUCTION

Patients with delusions typically seek less information when making decisions than controls ("jumping-to-conclusions", JTC) and paradoxically over-adjust to counter-evidence on probabilistic reasoning tasks. Previous studies have examined JTC bias across the delusion-prone continuum, but have not considered the co-occurrence of both biases at early stages of psychosis. This was our aim.

METHOD

Twenty-three early psychosis patients and 19 healthy controls completed two versions of the probabilistic reasoning task: a "draws-to-decision" version (to assess JTC) and a "graded-estimates" version (to assess over-adjustment). Both versions have been used previously with clinically delusional people with schizophrenia. IQ, memory and executive function were also examined.

RESULTS

Patients took fewer trials to reach a decision in the draws-to-decision version and showed greater over-adjustment to counter-evidence in the graded-estimates version than controls. Across groups, those who jumped to conclusions showed greater over-adjustment. Poor executive function predicted more extreme biases in controls but not in patients. Task performances were unrelated to memory. Similar results were evident in patient and control subgroups matched on IQ, and years of formal education.

CONCLUSIONS

A jumping-to-conclusions bias and an over-adjustment bias co-occurred in the early psychosis patients. Implications are discussed concerning the role of such biases in delusion-proneness.

Rationale and protocol for a systematic review and meta-analysis on reduced data gathering in people with delusions

BACKGROUND

The tendency to form conclusions based on limited evidence is known as the 'jumping to conclusions' (JTC) bias, and has been a much studied phenomena in individuals with psychosis. Previous reviews have supported the hypothesis that a JTC bias is particularly linked to the formation and maintenance of delusions. A new systematic review is required as a number of studies have since been published, and older reviews are limited by not systematically assessing methodological quality or the role of study design in influencing effect size estimates. This review aimed to investigate if there is an association between psychosis or delusions and JTC bias.

METHODS

The current protocol outlines the background and methodology for this systematic review and meta-analysis. Eligible articles will be identified through searches of the electronic databases PsycInfo, PubMed and Medline using relevant search terms, supplemented by hand-searches of references within eligible articles and key review articles within the field. Eligibility criteria were as follows: studies must recruit individuals with: i) schizophrenia spectrum conditions or ii) experiences of delusions. Case-control, cross-sectional, observational and prospective designs will be included but treatment trials and experimental studies excluded. Studies must use the beads task to assess JTC or a conceptually equivalent task. The outcomes will be the average number of 'draws to a decision' in the beads task (or related variant) and the proportion of the sample judged to demonstrate a JTC bias. Literature searches, study selection, data extraction, risk of bias assessment and outcome quality assessment will be undertaken by two independent reviewers. Meta-analyses will be undertaken for continuous (mean number of 'draws to a decision') and binary outcomes (number of people classified as having JTC bias).

DISCUSSION

Understanding of the size of the JTC effect and the contexts within which it occurs is important both in terms of informing models of delusional thinking and in guiding treatments for those with delusions or psychosis. However, a definitive, up-to-date review and meta-analysis of the JTC bias is currently lacking. The proposed review will fill this gap and resolve key issues regarding the factors which moderate the JTC bias.

PROSPERO REGISTRATION

CRD42014007603 http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42014007603.

Jumping to perceptions and to conclusions: specificity to hallucinations and delusions

BACKGROUND

There is evidence that people with psychosis display a "jump-to-conclusions" (JTC) reasoning style, and that this bias may be specific to delusions. A "jump-to-perceptions" (JTP) cognitive bias has also been found and is typically linked to hallucinations. However, there is some evidence for an association between JTP and delusions, and its specificity to hallucinations remains unclear. It has been suggested that these biases are related and products of shared cognitive processes.

METHODS

This study examined the symptom specificity of JTC and JTP, and the relationship between them, in a sample of 98 individuals with delusions divided into 'hallucinators' (n=51) and 'non-hallucinators' (n=47). Biases were assessed using the beads task and visual and auditory perceptual tasks.

RESULTS

As predicted, both groups demonstrated a JTC bias, but the 'hallucinators' showed a more pronounced JTP style in both modalities. The presence of JTC and JTP biases did not co-occur: making a decision on the beads task after two or fewer draws was not related to visual JTP, and was associated with a less marked JTP bias in the auditory perceptual task. No differences were found in JTP or JTC between participants with and without a schizophrenia diagnosis. JTP, but not JTC, was associated with the presence of hallucinations.

CONCLUSIONS

These findings suggest that the JTC and JTP biases show specificity to delusions and hallucinations, respectively, and not to diagnosis. There was no evidence that they are the product of shared cognitive processes, further supporting their specificity.

Paranoid thinking, suspicion, and risk for aggression: a neurodevelopmental perspective

This article represents an effort to extend our understanding of paranoia or suspicion and its development by integrating findings across clinical, developmental, and neuroscience literatures. We first define "paranoia" or paranoid thought and examine its prevalence across typically and atypically developing individuals and theoretical perspectives regarding its development and maintenance. We then briefly summarize current ideas regarding the neural correlates of adaptive, appropriately trusting interpersonal perception, social cognition, and behavior across development. Our focus shifts subsequently to examining in normative and atypical developmental contexts the neural correlates of several component cognitive processes thought to contribute to paranoid thinking: (a) attention bias for threat, (b) jumping to conclusions biases, and (c) hostile intent attribution biases. Where possible, we also present data regarding independent links between these cognitive processes and aggressive behavior. By examining data regarding the behavioral and neural correlates of varied cognitive processes that are likely components of a paranoid thinking style, we hope to advance both theoretical and empirical research in this domain.

When does jumping-to-conclusions reach its peak? The interaction of vulnerability and situation-characteristics in social reasoning

BACKGROUND AND OBJECTIVES

Persons with delusions tend to display a jumping-to-conclusions (JTC) bias which is considered relevant to delusion formation. However, its contribution in real life social scenarios is unknown. This study investigates whether JTC increases when decisions have to be made in delusion-relevant situations and whether the increase is uniquely moderated by delusion-proneness.

METHODS

JTC was assessed by a social reasoning paradigm in 92 healthy participants that were classified as high, medium or low in paranoid ideation and social anxiety. Decisions had to be made for emotionally salient scenarios without direct self-relevance, self-relevant scenarios and delusion-relevant scenarios, by successively drawing pieces of information.

RESULTS

All participants drew less information in the scenarios that were self-relevant and delusion-relevant compared to non-self-relevant scenarios. Participants with higher paranoid ideation generally drew less information than persons with medium or low levels of paranoid ideation. However, the hypothesized interaction of delusion-proneness and type of scenario was not significant. Social anxiety had no effect on draws to decision in any of the task types.

LIMITATIONS

The description of social encounters in the task does still not capture the full perceptual experience in real life encounters.

CONCLUSIONS

The data support the assumption that the formation of persecutory delusions might arise as a function of a delusion-specific JTC-bias in combination with a normal and functional tendency to collect less information in self-relevant situations.