A Bayesian predictive processing account of Othello syndrome in Parkinson's disease

Introduction: Although delusions in Parkinson's disease (PD) are rare, when they occur they frequently take the form of "Othello syndrome": the irrational belief that a spouse or partner is being unfaithful. Hitherto dismissed as either a by-product of dopamine therapy or cognitive impairment, there are still no convincing theoretical accounts to explain why only some patients fall prey to this delusion, or why it persists despite clear disconfirmatory evidence.Methods: We discuss the limitations of existing explanations of this delusion, namely hyperdopaminergia-induced anomalous perceptual experiences and cognitive impairment, before describing how Bayesian predictive processing accounts can provide a more comprehensive explanation by foregrounding the importance of prior experience and its impact upon computation of probability. We illustrate this new conceptualisation with three case vignettes.Results: We suggest that in those with prior experience of romantic betrayal, hyperdominergic-induced aberrant prediction errors enable anomalous perceptual experiences to accrue greater prominence, which is then maintained through Bayes-optimal inferencing to confirm cognitive distortions, eliciting and shaping this dangerous delusion.Conclusions: We propose the first comprehensive mechanistic account of Othello syndrome in PD and discuss implications for clinical interventions.

The Effect of Situational Experiment Conditions on Hasty Decision Making in the 'Beads Task'

'Jumping to Conclusions', or hasty decision making, is widely studied within clinical and computational psychology. It is typically investigated using the 'beads task', a sequential information sampling paradigm, and defining one or two draws as jumping to conclusion. Situational experimental conditions, e.g., group vs. individual testing, abstract vs. cover story, show-up fee or course credit, frequently vary between studies. Little effort has been dedicated to investigating the potential effects of demand characteristics on hasty decision making. We explored this in four samples of participants (n = 336), in different situational experiment conditions, with two distinct variations of the beads task. An abstract 'Draws to Decision' (DtD) variant, and a cover story combined DtD and probabilistic inferences variant. Situational conditions did not have a significant effect on overall DtD for either variant. However, when using 'extreme scores' (DtD of 1 or 1 to 2) as a measure of hasty decision making, situational conditions had an effect for the abstract variant, with individual testing having the fewest hasty decision makers (DtD1: Mann-Whitney U = 2137.5, p = 0.02; DtD1-2: Mann-Whitney U = 2017.5, p < 0.01), but not for the cover story variant. Our results suggest that the abstract variant is more susceptible to test conditions, especially if a categorisation is used to classify hasty decisions. This does not imply that the cover story variant is better suited to capturing jumping to conclusions behaviour, but highlights the importance of mirroring the situational conditions between different samples. We recommend that testing conditions should be fully disclosed.

A replication study of JTC bias, genetic liability for psychosis and delusional ideation

BACKGROUND

This study attempted to replicate whether a bias in probabilistic reasoning, or 'jumping to conclusions'(JTC) bias is associated with being a sibling of a patient with schizophrenia spectrum disorder; and if so, whether this association is contingent on subthreshold delusional ideation.

METHODS

Data were derived from the EUGEI project, a 25-centre, 15-country effort to study psychosis spectrum disorder. The current analyses included 1261 patients with schizophrenia spectrum disorder, 1282 siblings of patients and 1525 healthy comparison subjects, recruited in Spain (five centres), Turkey (three centres) and Serbia (one centre). The beads task was used to assess JTC bias. Lifetime experience of delusional ideation and hallucinatory experiences was assessed using the Community Assessment of Psychic Experiences. General cognitive abilities were taken into account in the analyses.

RESULTS

JTC bias was positively associated not only with patient status but also with sibling status [adjusted relative risk (aRR) ratio : 4.23 CI 95% 3.46-5.17 for siblings and aRR: 5.07 CI 95% 4.13-6.23 for patients]. The association between JTC bias and sibling status was stronger in those with higher levels of delusional ideation (aRR interaction in siblings: 3.77 CI 95% 1.67-8.51, and in patients: 2.15 CI 95% 0.94-4.92). The association between JTC bias and sibling status was not stronger in those with higher levels of hallucinatory experiences.

CONCLUSIONS

These findings replicate earlier findings that JTC bias is associated with familial liability for psychosis and that this is contingent on the degree of delusional ideation but not hallucinations.

Identifying and changing cognitive vulnerability in the classroom: preliminary evaluation of CUES-Ed, a school-based universal cognitive behavioural early intervention service for 7-10 year olds

BACKGROUND

School-based early intervention may alleviate current emotional and behavioural problems, and, by targeting underlying vulnerability, safeguard children's future mental health. Improving on mixed outcomes to date is an international public health priority. CUES-Ed is a classroom-based, clinician-led, universal cognitive behavioural programme for primary school children, designed to promote emotional literacy and regulation. Additionally, CUES-Ed targets cognitive mechanisms implicated in the future development of mental disorder: stigmatising appraisals of emotional expression and of unusual perceptual experiences, and the tendency to jump-to-conclusions (JTC). We report here on fitness for purpose of our in-service assessment of cognitive vulnerability, and change in cognitive vulnerability following CUES-Ed and compared with a naturalistic waitlist.

METHODS

From 05/2017-11/2017, 960 children participated (900 CUES-Ed; 60 naturalistic waitlist). Assessments were completed in whole classes; 732 children provided pre-post data on all measures; 227 were missing data through absence or poor completion (n = 1 declined assessment).

RESULTS

Relationships between baseline cognitive vulnerability measures and their components were consistent with reliable and valid assessment. Cognitive vulnerability reduced from before to after CUES-Ed and compared with the naturalistic waitlist, for JTC (large effects) and stigmatising appraisals (small-medium effects), for all children (ESs pre-post: 0.2-1.0; between-group: 0.1-1.0) and vulnerable subgroups (ESs pre-post: 0.5-1.7; between-group: 0.2-2.0).

CONCLUSIONS

Targeted cognitive vulnerability mechanisms change following CUES-Ed. As stigmatising appraisals and JTC may increase vulnerability to future mental illness, findings suggest a promise in reducing future risk. A formally controlled research study, with longer-term follow-up, is required to test this. Limitations and implications for future evaluation are discussed.

The jumping to conclusions reasoning bias as a cognitive factor contributing to psychosis progression and persistence: findings from NEMESIS-2

BACKGROUND

Contemporary models of psychosis implicate the importance of affective dysregulation and cognitive factors (e.g. biases and schemas) in the development and maintenance of psychotic symptoms, but studies testing proposed mechanisms remain limited. This study, uniquely using a prospective design, investigated whether the jumping to conclusions (JTC) reasoning bias contributes to psychosis progression and persistence.

METHODS

Data were derived from the second Netherlands Mental Health Survey and Incidence Study (NEMESIS-2). The Composite International Diagnostic Interview and an add-on instrument were used to assess affective dysregulation (i.e. depression, anxiety and mania) and psychotic experiences (PEs), respectively. The beads task was used to assess JTC bias. Time series analyses were conducted using data from T1 and T2 (N = 8666), excluding individuals who reported high psychosis levels at T0.

RESULTS

Although the prospective design resulted in low statistical power, the findings suggest that, compared to those without symptoms, individuals with lifetime affective dysregulation were more likely to progress from low/moderate psychosis levels (state of 'aberrant salience', one or two PEs) at T1 to high psychosis levels ('frank psychosis', three or more PEs or psychosis-related help-seeking behaviour) at T2 if the JTC bias was present [adj. relative risk ratio (RRR): 3.8, 95% confidence interval (CI) 0.8-18.6, p = 0.101]. Similarly, the JTC bias contributed to the persistence of high psychosis levels (adj. RRR: 12.7, 95% CI 0.7-239.6, p = 0.091).

CONCLUSIONS

We found some evidence that the JTC bias may contribute to psychosis progression and persistence in individuals with affective dysregulation. However, well-powered prospective studies are needed to replicate these findings.

Jumping to conclusions, general intelligence, and psychosis liability: findings from the multi-centre EU-GEI case-control study

BACKGROUND

The 'jumping to conclusions' (JTC) bias is associated with both psychosis and general cognition but their relationship is unclear. In this study, we set out to clarify the relationship between the JTC bias, IQ, psychosis and polygenic liability to schizophrenia and IQ.

METHODS

A total of 817 first episode psychosis patients and 1294 population-based controls completed assessments of general intelligence (IQ), and JTC, and provided blood or saliva samples from which we extracted DNA and computed polygenic risk scores for IQ and schizophrenia.

RESULTS

The estimated proportion of the total effect of case/control differences on JTC mediated by IQ was 79%. Schizophrenia polygenic risk score was non-significantly associated with a higher number of beads drawn (B = 0.47, 95% CI -0.21 to 1.16, p = 0.17); whereas IQ PRS (B = 0.51, 95% CI 0.25-0.76, p < 0.001) significantly predicted the number of beads drawn, and was thus associated with reduced JTC bias. The JTC was more strongly associated with the higher level of psychotic-like experiences (PLEs) in controls, including after controlling for IQ (B = -1.7, 95% CI -2.8 to -0.5, p = 0.006), but did not relate to delusions in patients.

CONCLUSIONS

Our findings suggest that the JTC reasoning bias in psychosis might not be a specific cognitive deficit but rather a manifestation or consequence, of general cognitive impairment. Whereas, in the general population, the JTC bias is related to PLEs, independent of IQ. The work has the potential to inform interventions targeting cognitive biases in early psychosis.

Schizotypy is associated with difficulty maintaining multiple hypotheses

Among neurocognitive accounts of delusions, there is a growing consensus that it is the certainty with which delusions are held, rather than their content that defines some beliefs as delusional. On a continuum model of psychosis, this inappropriate certainty ought to be present (albeit in an attenuated form) in healthy adults who score highly in schizotypy. It was hypothesised that this might be most evident in circumstances where the environment provides incomplete or probabilistic information, which thereby forces the participant to hold two imperfectly supported, concurrent hypotheses in mind. A cued visual search task was used to measure people's capacity to use partially predictive information (i.e., a cue that predicted the target may occur in one of the two locations) to facilitate speeded responding. As hypothesised, people's performance on the trials that required holding two hypotheses in mind concurrently was significantly and specifically associated with the positive components of schizotypy. This finding is consistent with a hyperfocusing of attention in schizophrenia, and may help explain why delusion-prone individuals have a tendency to "jump to conclusions" or be resistant to disconfirming information when faced with multiple, partially supported hypotheses.

Probing the Hypersalience Hypothesis-An Adapted Judge-Advisor System Tested in Individuals With Psychotic-Like Experiences

Individuals with psychotic-like experiences and psychosis gather and use information differently than controls; in particular they seek and rely on less information or over-weight currently available information. A new paradigm, the judge-advisor system, has previously been used to investigate these processes. Results showed that psychosis-prone individuals tend to seek less advice but at the same time use the available advice more. Some theoretical models, like the hypersalience of evidence-matching hypothesis, predict that psychosis-prone individuals weight recently available information to a greater extent and thus provide an explanation for increased advice-weighting scores in psychosis-prone individuals. To test this model, we adapted the previously used judge-advisor system by letting participants receive consecutively multiple pieces of advice. To meet this aim, we recruited a large MTurk community sample (N = 1,396), which we split in a group with high levels of psychotic-like experiences (at least 2 SD above the mean, n = 80) and a group with low levels of psychotic-like experiences (maximum 0.5 SD above the mean, n = 1,107), using the Community Assessment of Psychic Experiences' positive subscale. First, participants estimated five people's age based on photographs. Then, they received consecutive advice in the form of manipulated age estimates by allegedly previous participants, with outliers in some trials. After each advice, participants could adjust their estimate. This procedure allowed us to investigate how participants weighted each currently presented advice. In addition to being more confident in their final estimates and in line with our preregistered hypothesis, participants with more frequent psychotic-like experiences did weight currently available advice more than participants with less frequent psychotic-like experiences. This effect was especially pronounced in response to outliers, as fine-grained post-hoc analysis suggested. Result thus support models predicting an overcorrection in response to new incoming information and challenges an assumed general belief inflexibility in people with psychotic experiences.

Corrigendum: Thinking Preferences and Conspiracy Belief: Intuitive Thinking and the Jumping to Conclusions-Bias as a Basis for the Belief in Conspiracy Theories

[This corrects the article DOI: 10.3389/fpsyt.2020.568942.].

Time will tell: Decision making in premanifest and manifest Huntington's disease

OBJECTIVE

To investigate cognitive flexibility in premanifest and manifest Huntington's disease (HD).

BACKGROUND

HD is an autosomal dominant neurodegenerative disease characterized by motor, cognitive, and behavioral abnormalities with typical motor symptoms. In this study, we wanted to assess decision making in premanifest (pre-HD) and manifest HD patients.

METHODS

A total of 77 non-demented subjects including 29 pre-HD, 22 manifest HD patients, and 26 healthy controls (HC) were included. We stratified the pre-HD group based on their estimated years to disease onset into a far (FAR, n = 13) and a near (NEAR, n = 16) group. Furthermore, participants performed the Montreal cognitive assessment battery (MoCA), the trail making task part A and B (TMT A, TMT B), the Symbol digit modalities test (SDMT), and the beads task.

RESULTS

In the beads task, HD patients gathered less information than all other groups (all p-values < .001). Furthermore, the NEAR group gathered less information than the FAR group (p < .001) and HC (p = .001). There was no difference between the HC and the FAR group (p = 1.0). In the TMT and the SDMT, HD patients were slower than all other groups (all p-values < .01) but there were no other significant differences.

CONCLUSIONS

Decision making with a higher degree of uncertainty may be an early neuropsychological sign to indicate the disease process prior to reaching criteria for motor diagnosis of HD.

Thinking Preferences and Conspiracy Belief: Intuitive Thinking and the Jumping to Conclusions-Bias as a Basis for the Belief in Conspiracy Theories

BACKGROUND

The belief in conspiracy theories and paranoid ideation are often treated as almost synonymous. However, there is to date no research concerning shared underlying cognitive underpinnings of belief in conspiracy theories and paranoid ideation. One potential underlying factor could be the well-known jumping to conclusion (JTC) bias, the tendency of persons with delusions to perform hasty decisions that are sometimes based on little evidence. Furthermore, a preference for a more intuitive general thinking style, as opposed to an analytical thinking style, could be an additional underlying cognitive factor of both conspiracy theories and paranoia. Thus, the aim of the present study is to investigate in a large sample of non-clinical individuals whether the JTC-bias is more pronounced in individuals who display a stronger belief in conspiracy theories and whether both are related to a more intuitive thinking preference.

METHODS

We assessed the data of 519 non-clinical individuals regarding their respective approval of 20 specific conspiracy theories in an online study. Further, we assessed the JTC-bias by using a computerized variant of the beads task (fish task). Thinking preferences were measured with the Rational-Experiential Interview.

RESULTS

Subjects who displayed the JTC-bias presented a more pronounced belief in conspiracy theories. In addition, gathering little information in the fish task before performing a decision (less draws to decision) was related to a stronger endorsement of conspiracy theories and a more intuitive thinking style (and a less analytic thinking style). Finally, a preference for intuitive thinking predicted a stronger belief in conspiracy theories in a multiple regression analysis.

CONCLUSIONS

Our results demonstrate the implication of a preference for an intuitive thinking style accompanied by a propensity to faster decision-making (JTC-bias) as possible cognitive underpinnings of beliefs in conspiracy theories. Furthermore, our study is the first to confirm the notion of the JTC-bias as a reflection of the use of an intuitive thinking style.

Effort and liberal acceptance bias in patients with schizophrenia

Introduction: A liberal acceptance bias is implicated in the formation and maintenance of delusions in schizophrenia. The present study tested the hypothesis that patients with schizophrenia are more quickly satisfied with their task performance than controls despite poor objective performance. Methods: Fifty patients with schizophrenia and 50 healthy controls performed the newly developed copy figure task in which participants copy a complex geometrical figure up to eight times until they are satisfied with the result. Objective performance was scored blind to group status. Subjective performance was rated on a 10-point scale. Carefulness of the drawing using anchor points served as a proxy for effort. Results: Patients made as many attempts as controls to copy the figure despite their worse subjective and objective performance. The number of attempts was negatively correlated with (persecutory) delusions and the PANSS total score. Neither effort nor possible frustration due to a plateau in performance was a reason for task termination. Conclusions: This exploratory study is in line with predictions based on the liberal acceptance model. For future studies, we recommend further cross-validating this paradigm and testing whether patients' retrospective assessment of their performance is exaggerated relative to controls. We also suggest that researchers pursue this line of research with personally meaningful material where a decreased threshold of acceptance may more easily translate into the subsequent fixation of ideas.

Jumping to conclusions at first onset of psychosis predicts longer admissions, more compulsory admissions and police involvement over the next 4 years: the GAP study

BACKGROUND

Jumping to conclusions (JTC), which is the proneness to require less information before forming beliefs or making a decision, has been related to formation and maintenance of delusions. Using data from the National Institute of Health Research Biomedical Research Centre Genetics and Psychosis (GAP) case-control study of first-episode psychosis (FEP), we set out to test whether the presence of JTC would predict poor clinical outcome at 4 years.

METHODS

One-hundred and twenty-three FEP patients were assessed with the Positive and Negative Syndrome Scale (PANSS), Global Assessment of Functioning (GAF) and the probabilistic reasoning 'Beads' Task at the time of recruitment. The sample was split into two groups based on the presence of JTC bias. Follow-up data over an average of 4 years were obtained concerning clinical course and outcomes (remission, intervention of police, use of involuntary treatment - the Mental Health Act (MHA) - and inpatient days).

RESULTS

FEP who presented JTC at baseline were more likely during the follow-up period to be detained under the MHA [adjusted OR 15.62, 95% confidence interval (CI) 2.92-83.54, p = 0.001], require intervention by the police (adjusted OR 14.95, 95% CI 2.68-83.34, p = 0.002) and have longer admissions (adjusted IRR = 5.03, 95% CI 1.91-13.24, p = 0.001). These associations were not accounted for by socio-demographic variables, IQ and symptom dimensions.

CONCLUSIONS

JTC in FEP is associated with poorer outcome as indicated and defined by more compulsion police intervention and longer periods of admission. Our findings raise the question of whether the implementation of specific interventions to reduce JTC, such as Metacognition Training, may be a useful addition in early psychosis intervention programmes.

Reasoning bias, working memory performance and a transdiagnostic phenotype of affective disturbances and psychotic experiences in the general population

BACKGROUND

The jumping to conclusions (JTC) reasoning bias and decreased working memory performance (WMP) are associated with psychosis, but associations with affective disturbances (i.e. depression, anxiety, mania) remain inconclusive. Recent findings also suggest a transdiagnostic phenotype of co-occurring affective disturbances and psychotic experiences (PEs). This study investigated whether JTC bias and decreased WMP are associated with co-occurring affective disturbances and PEs.

METHODS

Data were derived from the second Netherlands Mental Health Survey and Incidence Study (NEMESIS-2). Trained interviewers administered the Composite International Diagnostic Interview (CIDI) at three time points in a general population sample (N = 4618). The beads and digit-span task were completed to assess JTC bias and WMP, respectively. CIDI was used to measure affective disturbances and an add-on instrument to measure PEs.

RESULTS

Compared to individuals with neither affective disturbances nor PEs, the JTC bias was more likely to occur in individuals with co-occurring affective disturbances and PEs [moderate psychosis (1-2 PEs): adjusted relative risk ratio (RRR) 1.17, 95% CI 0.98-1.41; and high psychosis (3 or more PEs or psychosis-related help-seeking behaviour): adjusted RRR 1.57, 95% CI 1.19-2.08], but not with affective disturbances and PEs alone, whereas decreased WMP was more likely in all groups. There was some evidence of a dose-response relationship, as JTC bias and decreased WMP were more likely in individuals with affective disturbances as the level of PEs increased or help-seeking behaviour was reported.

CONCLUSION

The findings suggest that JTC bias and decreased WMP may contribute to a transdiagnostic phenotype of co-occurring affective disturbances and PEs.

Does uncertainty breed conviction? On the possible role of compensatory conviction in jumping to conclusions and overconfidence in psychosis

Background: Jumping to conclusions (JTC) and overconfidence in errors are well established in individuals with a liability to psychosis. Experimental research suggests that subjecting individuals to dilemmas and doubt prompts a subsequent hardening of attitudes and may foster delusion-like convictions. For the present study, we examined whether this compensatory conviction process is exaggerated in individuals with a liability to psychosis and might in part explain JTC and overconfidence. Methods: A large sample of participants from the general population were screened for psychotic experiences with the Community Assessment of Psychic Experiences scale (CAPE) and then randomly allocated to either a condition in which they should experience doubt or a control condition. Participants (final sample, n = 650) were then tested on JTC and overconfidence. Results: Participants who scored high on the positive subscale of the CAPE made fewer draws to decision, showed greater confidence, and made more errors relative to low scorers. Yet, none of the parameters was modulated by experimental condition. Conclusions: Our results at present do not support the idea that JTC is elevated by a prior experience of a dilemma or doubt. Yet, this possibility should not be entirely dismissed as the presumed process may take time to evolve and perhaps needs to be more pervasive.

Cost Evaluation During Decision-Making in Patients at Early Stages of Psychosis

Jumping to conclusions during probabilistic reasoning is a cognitive bias reliably observed in psychosis and linked to delusion formation. Although the reasons for this cognitive bias are unknown, one suggestion is that psychosis patients may view sampling information as more costly. However, previous computational modeling has provided evidence that patients with chronic schizophrenia jump to conclusions because of noisy decision-making. We developed a novel version of the classical beads task, systematically manipulating the cost of information gathering in four blocks. For 31 individuals with early symptoms of psychosis and 31 healthy volunteers, we examined the numbers of "draws to decision" when information sampling had no, a fixed, or an escalating cost. Computational modeling involved estimating a cost of information sampling parameter and a cognitive noise parameter. Overall, patients sampled less information than controls. However, group differences in numbers of draws became less prominent at higher cost trials, where less information was sampled. The attenuation of group difference was not due to floor effects, as in the most costly block, participants sampled more information than an ideal Bayesian agent. Computational modeling showed that, in the condition with no objective cost to information sampling, patients attributed higher costs to information sampling than controls did, Mann-Whitney U = 289, p = 0.007, with marginal evidence of differences in noise parameter estimates, t(60) = 1.86, p = 0.07. In patients, individual differences in severity of psychotic symptoms were statistically significantly associated with higher cost of information sampling, ρ = 0.6, p = 0.001, but not with more cognitive noise, ρ = 0.27, p = 0.14; in controls, cognitive noise predicted aspects of schizotypy (preoccupation and distress associated with delusion-like ideation on the Peters Delusion Inventory). Using a psychological manipulation and computational modeling, we provide evidence that early-psychosis patients jump to conclusions because of attributing higher costs to sampling information, not because of being primarily noisy decision makers.

Individualized Metacognitive Training (MCT+) Reduces Delusional Symptoms in Psychosis: A Randomized Clinical Trial

Individualized metacognitive training (MCT+) is a novel psychotherapy that has been designed to specifically target delusional beliefs in people with psychosis. It works by developing an awareness of the implausible content of delusional beliefs, while also targeting the cognitive biases that contribute to their formation and maintenance. It was expected that MCT+ would lead to significantly greater reductions in delusional severity compared to a cognitive remediation (CR) active control condition. A total of 54 patients with a schizophrenia spectrum disorder and active delusions were randomized into four 2-hourly sessions of MCT+ (n = 27) or CR (n = 27). All participants completed posttreatment assessment, and only 2 participants did not complete 6-month follow-up assessment, resulting in MCT+ (n = 26) and CR (n = 26) for final analysis. The primary outcome measures of delusional and positive symptom severity were assessed rater-blind; secondary outcome assessment was non-blinded and included clinical and cognitive insight, the jumping to conclusions (JTC) bias, and cognitive functioning. Participants in the MCT+ condition showed significant reductions in delusional and overall positive symptom severity (large effect) and improved clinical insight (moderate effect) relative to CR controls. In contrast, CR controls showed moderate improvement in problem-solving ability relative to MCT+, but no other cognitive domain. Importantly, these findings were maintained at 6-month follow-up. The study adds further efficacy to the MCT program, and suggests that even brief psychotherapy can help to ameliorate the symptoms of psychosis.

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.

Who "jumps to conclusions"? A comprehensive assessment of probabilistic reasoning in psychosis following traumatic brain injury (PFTBI), and comparison with TBI, schizophrenia, and nonclinical controls

INTRODUCTION

The "jumping to conclusions" (JTC) bias has received significant attention in the schizophrenia and delusion literature as an important aspect of cognition characterising psychosis. The JTC bias has not been explored in psychosis following traumatic brain injury (PFTBI).

METHODS

JTC was investigated in 10 patients with PFTBI using the beads task (ratios 85:15 and 60:40). Probabilistic predictions, draws-to-decision, self-rated decision confidence, and JTC bias were recorded. Responses from 10 patients with traumatic brain injury (TBI), 23 patients with schizophrenia, and 23 nonclinical controls were compared. Relationships were explored between draws-to-decision and current intelligence quotient, affective state, executive function, delusions (severity and type), and illness chronicity (duration).

RESULTS

Groups were comparable on JTC measures. Delusion severity and type were not related to draws-to-decision for either trial. In the entire sample, executive function (reduced mental flexibility) was significantly related to more draws-to-decision on the 60:40 ratio trial.

CONCLUSIONS

We found no evidence for an elevated JTC bias in patients with PFTBI or TBI alone. The influence of executive dysfunction should be considered by future studies using the beads tasks in patient populations. These findings need to be replicated in larger PFTBI and TBI samples.

Analytic cognitive style, not delusional ideation, predicts data gathering in a large beads task study

INTRODUCTION

It has been proposed that deluded and delusion-prone individuals gather less evidence before forming beliefs than those who are not deluded or delusion-prone. The primary source of evidence for this "jumping to conclusions" (JTC) bias is provided by research that utilises the "beads task" data-gathering paradigm. However, the cognitive mechanisms subserving data gathering in this task are poorly understood.

METHODS

In the largest published beads task study to date (n = 558), we examined data gathering in the context of influential dual-process theories of reasoning.

RESULTS

Analytic cognitive style (the willingness or disposition to critically evaluate outputs from intuitive processing and engage in effortful analytic processing) predicted data gathering in a non-clinical sample, but delusional ideation did not.

CONCLUSION

The relationship between data gathering and analytic cognitive style suggests that dual-process theories of reasoning can contribute to our understanding of the beads task. It is not clear why delusional ideation was not found to be associated with data gathering or analytic cognitive style.

Bayesian accounts and black swans: Questioning the erotetic theory of delusional thinking

Parrott and Koralus argue that a particular cognitive factor--"impaired endogenous question raising"--offers a parsimonious account of three delusion-related phenomena: (1) the development of the Capgras delusion; (2) evidence that patients with schizophrenia outperform healthy control participants on a conditional reasoning task; and (3) evidence that deluded individuals "jump to conclusions". In this response, I assess these claims, and raise my own questions about the "erotetic" theory of delusional thinking.

The erotetic theory of delusional thinking

INTRODUCTION

In this paper, we argue for a novel account of one cognitive factor implicated in delusional cognition. According to the erotetic theory of delusion we present, the central cognitive factor in delusion is impaired endogenous question raising.

METHOD

After presenting the erotetic theory, we draw on it to model three distinct patterns of reasoning exhibited by delusional and schizophrenic patients, and contrast our explanations with Bayesian alternatives.

RESULTS

We argue that the erotetic theory has considerable advantages over Bayesian models. Specifically, we show that it offers a superior explanation of three phenomena: the onset and persistence of the Capgras delusion; recent data indicating that schizophrenic subjects manifest superior reasoning with conditionals in certain contexts; and evidence that schizophrenic and delusional subjects have a tendency to "jump to conclusions." Moreover, since the cognitive mechanisms we appeal to are independently motivated, we avoid having to posit distinct epistemic states that are intrinsically irrational in order to fit our model to the variety of data.

CONCLUSION

In contrast to Bayesian models, the erotetic theory offers a simple, unified explanation of a range of empirical data. We therefore conclude that it offers a more plausible framework for explaining delusional cognition.

Psychosis, Delusions and the "Jumping to Conclusions" Reasoning Bias: A Systematic Review and Meta-analysis

We did a systematic review and meta-analysis to investigate the magnitude and specificity of the "jumping to conclusions" (JTC) bias in psychosis and delusions. We examined the extent to which people with psychosis, and people with delusions specifically, required less information before making decisions. We examined (1) the average amount of information required to make a decision and (2) numbers who demonstrated an extreme JTC bias, as assessed by the "beads task." We compared people with psychosis to people with and without nonpsychotic mental health problems, and people with psychosis with and without delusions. We examined whether reduced data-gathering was associated with increased delusion severity. We identified 55 relevant studies, and acquired previously unpublished data from 16 authors. People with psychosis required significantly less information to make decisions than healthy individuals (k= 33,N= 1935,g= -0.53, 95% CI -0.69, -0.36) and those with nonpsychotic mental health problems (k= 13,N= 667,g= -0.58, 95% CI -0.80, -0.35). The odds of extreme responding in psychosis were between 4 and 6 times higher than the odds of extreme responding by healthy participants and participants with nonpsychotic mental health problems. The JTC bias was linked to a greater probability of delusion occurrence in psychosis (k= 14,N= 770, OR 1.52, 95% CI 1.12, 2.05). There was a trend-level inverse association between data-gathering and delusion severity (k= 18;N= 794;r= -.09, 95% CI -0.21, 0.03). Hence, nonaffective psychosis is characterized by a hasty decision-making style, which is linked to an increased probability of delusions.

Paranoid thinking, cognitive bias and dangerous neighbourhoods: Implications for perception of threat and expectations of victimisation

BACKGROUND

Paranoid thinking is prevalent in the non-clinical population and cognitive mechanisms of heuristic reasoning and jumping to conclusions bias contributes to its formation and maintenance.

AIMS

This study investigated the degree to which paranoia, perceived environmental risk, heuristic reasoning and jumping to conclusions bias (measured with the beads task) contribute to misinterpretation of neutral stimuli, and whether this informed judgements regarding vulnerability to threat and crime. It is also investigated whether impulsiveness is a confounding factor on the beads task.

METHODS

Two hundred participants were recruited using a snowball-sampling method for a quantitative cross-sectional study. Participants reported demographic information, three psychometric questionnaires and two experimental tasks via an online paradigm hosted by the Bristol Online Survey tool.

RESULTS

Participants with high paranoia scores perceived their environment to be more dangerous than those with low scores. Participants with high paranoia scores also overestimated threat in neutral stimuli and had high expectations of future victimisation. Jumping to conclusions on the beads task did not predict fear of crime outcomes, but was predicted by impulsivity.

CONCLUSION

Participants who demonstrated paranoid thinking were more likely to reside in perceived dangerous neighbourhoods and overestimate threat. While this could indicate a paranoid heuristic, it is a potentially rational response to prior experiences of crime and victimisation. Implications and suggestions for future research are discussed.

Jumping to Conclusions About the Beads Task? A Meta-analysis of Delusional Ideation and Data-Gathering

It has been claimed that delusional and delusion-prone individuals have a tendency to gather less data before forming beliefs. Most of the evidence for this "jumping to conclusions" (JTC) bias comes from studies using the "beads task" data-gathering paradigm. However, the evidence for the JTC bias is mixed. We conducted a random-effects meta-analysis of individual participant data from 38 clinical and nonclinical samples (n = 2,237) to investigate the relationship between data gathering in the beads task (using the "draws to decision" measure) and delusional ideation (as indexed by the "Peters et al Delusions Inventory"; PDI). We found that delusional ideation is negatively associated with data gathering (r(s) = -0.10, 95% CI [-0.17, -0.03]) and that there is heterogeneity in the estimated effect sizes (Q-stat P = .03, I(2) = 33). Subgroup analysis revealed that the negative association is present when considering the 23 samples (n = 1,754) from the large general population subgroup alone (r(s) = -0.10, 95% CI [-0.18, -0.02]) but not when considering the 8 samples (n = 262) from the small current delusions subgroup alone (r(s) = -0.12, 95% CI [-0.31, 0.07]). These results provide some provisional support for continuum theories of psychosis and cognitive models that implicate the JTC bias in the formation and maintenance of delusions.

Delusion proneness and 'jumping to conclusions': relative and absolute effects

BACKGROUND

That delusional and delusion-prone individuals 'jump to conclusions' is one of the most robust and important findings in the literature on delusions. However, although the notion of 'jumping to conclusions' (JTC) implies gathering insufficient evidence and reaching premature decisions, previous studies have not investigated whether the evidence gathering of delusion-prone individuals is, in fact, suboptimal. The standard JTC effect is a relative effect but using relative comparisons to substantiate absolute claims is problematic. In this study we investigated whether delusion-prone participants jump to conclusions in both a relative and an absolute sense.

METHOD

Healthy participants (n = 112) completed an incentivized probabilistic reasoning task in which correct decisions were rewarded and additional information could be requested for a small price. This combination of rewards and costs generated optimal decision points. Participants also completed measures of delusion proneness, intelligence and risk aversion.

RESULTS

Replicating the standard relative finding, we found that delusion proneness significantly predicted task decisions, such that the more delusion prone the participants were, the earlier they decided. This finding was robust when accounting for the effects of risk aversion and intelligence. Importantly, high-delusion-prone participants also decided in advance of an objective rational optimum, gathering fewer data than would have maximized their expected payoff. Surprisingly, we found that even low-delusion-prone participants jumped to conclusions in this absolute sense.

CONCLUSIONS

Our findings support and clarify the claim that delusion formation is associated with a tendency to 'jump to conclusions'. In short, most people jump to conclusions, but more delusion-prone individuals 'jump further'.

Cognitive mechanisms of change in delusions: an experimental investigation targeting reasoning to effect change in paranoia

BACKGROUND

Given the evidence that reasoning biases contribute to delusional persistence and change, several research groups have made systematic efforts to modify them. The current experiment tested the hypothesis that targeting reasoning biases would result in change in delusions.

METHODS

One hundred and one participants with current delusions and schizophrenia spectrum psychosis were randomly allocated to a brief computerized reasoning training intervention or to a control condition involving computer-based activities of similar duration. The primary hypotheses tested were that the reasoning training intervention, would improve (1) data gathering and belief flexibility and (2) delusional thinking, specifically paranoia. We then tested whether the changes in paranoia were mediated by changes in data gathering and flexibility, and whether working memory and negative symptoms moderated any intervention effects.

RESULTS

On an intention-to-treat analysis, there were significant improvements in state paranoia and reasoning in the experimental compared with the control condition. There was evidence that changes in reasoning mediated changes in paranoia, although this effect fell just outside the conventional level of significance after adjustment for baseline confounders. Working memory and negative symptoms significantly moderated the effects of the intervention on reasoning.

CONCLUSION

The study demonstrated the effectiveness of a brief reasoning intervention in improving both reasoning processes and paranoia. It thereby provides proof-of-concept evidence that reasoning is a promising intermediary target in interventions to ameliorate delusions, and thus supports the value of developing this approach as a longer therapeutic intervention.

Jumping to conclusions, neuropsychological functioning, and delusional beliefs in first episode psychosis

BACKGROUND

The "jumping to conclusions" (JTC) data-gathering bias is implicated in the development and maintenance of psychosis but has only recently been studied in first episode psychosis (FEP). In this study, we set out to establish the relationship of JTC in FEP with delusions and neuropsychological functioning.

METHODS

One hundred and eight FEP patients and 101 age-matched controls completed assessments of delusions, general intelligence (IQ), working memory (WM), and JTC (the probabilistic reasoning "beads" task).

RESULTS

Half the FEP participants jumped to conclusions on at least 1 task, compared with 25% of controls (OR range 2.1 to 3.9; 95% CI range 1.5 to 8.0, P values ≤ .02). JTC was associated with clinical, but not nonclinical delusion severity, and with neuropsychological functioning, irrespective of clinical status. Both IQ and delusion severity, but not WM, were independently associated with JTC in the FEP group.

CONCLUSIONS

JTC is present in FEP. The specific association of JTC with clinical delusions supports a state, maintaining role for the bias. The associations of JTC with neuropsychological functioning indicate a separable, trait aspect to the bias, which may confer vulnerability to psychosis. The work has potential to inform emerging interventions targeting reasoning biases in early psychosis.

Investigating the 'jumping to conclusions' bias in people with anorexia nervosa

'Jumping to conclusions' (JTC) is an established reasoning bias in people with psychosis and delusion proneness. Research investigating the JTC bias in other clinical populations remains in its infancy. This study investigated whether individuals with anorexia (AN) displayed the JTC bias compared with healthy controls and, if so, whether the bias was greater in relation to emotionally salient information. The study also investigated whether delusionality was correlated with the JTC bias. JTC was measured using the 'beads task'. Three versions were employed: the standard version and two emotionally salient tasks. Results indicated that a majority (55.6%) of people with AN (n=26) displayed poor insight into their eating disorder beliefs but did not display an elevated JTC compared with healthy controls (n=33) on any task. The level of delusionality in the AN group was not correlated with JTC bias. Findings suggest that although a majority of people with AN demonstrated limited insight, they did not display the JTC bias. This may suggest that poor insight in eating disorders has different characteristics to that found in psychotic disorders, which may suggest that differences are needed in relation to how they are treated using psychological means. However, this was a small study, and study replication is required.

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.

Dopaminergic modulation of probabilistic reasoning and overconfidence in errors: a double-blind study

INTRODUCTION

Reasoning biases such as jumping to conclusions (JTC) and overconfidence in errors have been well replicated in patients with delusions. However, their relation to dopaminergic activity, central to pathophysiologic models of psychosis, has not yet been investigated. This study aimed to examine the effects of a dopaminergic agonist (L-dopa) and a dopaminergic antagonist (haloperidol) on the JTC bias and overconfidence in errors after single-dose administration in healthy individuals.

METHODS

The study used a randomized, double-blind, placebo-controlled, 3-way crossover design. Participants were 36 healthy individuals aged 18-36 years. The variables of interest were draws to decision and probability threshold to decision on a computerized variant of the beads task and the number of high-confident incorrect responses on a visual memory task.

RESULTS

There were no significant effects of substance on draws to decision and probability threshold to decision. A significant effect emerged for high-confident incorrect responses in the memory task; pairwise comparisons indicated a significant reduction of the number of high-confident incorrect responses after administration of haloperidol vs l-dopa and placebo.

CONCLUSIONS

This is the first study to investigate the direct effects of dopaminergic drugs on reasoning biases. The JTC bias and overconfidence in errors showed a differential pattern of dopaminergic modulation, suggesting that they represent different facets of reasoning abnormalities that interact with each other to produce delusions in susceptible individuals.

Differences in cognitive and emotional processes between persecutory and grandiose delusions

BACKGROUND

Cognitive models propose that cognitive and emotional processes, in the context of anomalies of experience, lead to and maintain delusions. No large-scale studies have investigated whether persecutory and grandiose delusions reflect differing contributions of reasoning and affective processes. This is complicated by their frequent cooccurrence in schizophrenia. We hypothesized that persecutory and grandiose subtypes would differ significantly in their associations with psychological processes.

METHODS

Participants were the 301 patients from the Psychological Prevention of Relapse in Psychosis Trial (ISRCTN83557988). Persecutory delusions were present in 192 participants, and grandiose delusions were present in 97, while 58 were rated as having delusions both of persecution and grandiosity. Measures of emotional and reasoning processes, at baseline only, were employed.

RESULTS

A bivariate response model was used. Negative self-evaluations and depression and anxiety predicted a significantly increased chance of persecutory delusions whereas grandiose delusions were predicted by less negative self-evaluations and lower anxiety and depression, along with higher positive self and positive other evaluations. Reasoning biases were common in the whole group and in categorically defined subgroups with only persecutory delusions and only grandiose delusions; however, jumping to conclusions, and belief flexibility were significantly different in the 2 groups, the grandiose group having a higher likelihood of showing a reasoning bias than the persecutory group.

CONCLUSION

The significant differences in the processes associated with these 2 delusion subtypes have implications for etiology and for the development of targeted treatment strategies.

Elucidating the black box from stress to paranoia

Sensitivity to stress has long been implicated in the pathogenesis of schizophrenia. It remains unclear, however, which exact mechanisms underlie the progression from vulnerability to psychotic breakdown. For the present study, we hypothesized that the induction of stress would aggravate cognitive biases in schizophrenia. A total of 20 acute and remitted schizophrenia patients and 15 healthy controls were tested with parallel versions of cognitive biases paradigms under 2 laboratory conditions: stress (loud noise, 75 dB) vs no-stress. In the course of both conditions, participants had to fill out a questionnaire that assessed depressive, obsessive-compulsive, and paranoid symptoms. For the patients with acute psychotic symptoms, paranoid but not other psychiatric symptoms were elevated under stress in comparison with no-stress. In contrast, stress somewhat diminished subclinical paranoid symptoms in healthy participants. Jumping to conclusions was evident in schizophrenia under both conditions but significantly more pronounced when stress was applied first in the acute group. A tendency emerged in both acute and remitted patients to attribute events to other people under stress which was not seen in healthy subjects. The present study may serve as a starting point for further research investigating how stress translates vulnerability into acute paranoia and to pinpoint cognitive risk factors that can be modified by treatment.

Targeting reasoning biases in delusions: a pilot study of the Maudsley Review Training Programme for individuals with persistent, high conviction delusions

Delusions are often resistant to change, persisting despite successful antipsychotic treatment or Cognitive Behavioural Therapy. This study aimed to target reasoning processes, particularly the 'Jumping to Conclusions' (JTC) bias and belief flexibility, which are thought to play a part in maintaining delusional conviction. 13 participants with a diagnosis of psychosis and high levels of conviction in their delusions completed a one-off computerised training package, lasting approximately 1.5 h. Outcomes were assessed at baseline, pre-intervention (two weeks later), post-intervention (immediately after completing the training) and at 1 month follow-up. The package was well received by participants. There were improvements in JTC, belief flexibility and delusional conviction between pre- and post-intervention measures. Controlled studies powered to detect changes in key outcomes are warranted in order to evaluate the efficacy of the programme.