Reasoning in psychosis: risky but not necessarily hasty

Modeling Decision-Making in Schizophrenia: Associations Between Computationally Derived Risk Propensity and Self-Reported Risk Perception

BACKGROUND AND HYPOTHESIS

Schizophrenia is associated with a decreased pursuit of risky rewards during uncertain-risk decision-making. However, putative mechanisms subserving this disadvantageous risky reward pursuit, such as contributions of cognition and relevant traits, remain poorly understood.

STUDY DESIGN

Participants (30 schizophrenia/schizoaffective disorder [SZ]; 30 comparison participants [CP]) completed the Balloon Analogue Risk Task (BART). Computational modeling captured subprocesses of uncertain-risk decision-making: Risk Propensity, Prior Belief of Success, Learning Rate, and Behavioral Consistency. IQ, self-reported risk-specific processes (ie, Perceived Risks and Expected Benefit of Risks), and non-risk-specific traits (ie, defeatist beliefs; hedonic tone) were examined for relationships with Risk Propensity to determine what contributed to differences in risky reward pursuit.

STUDY RESULTS

On the BART, the SZ group exhibited lower Risk Propensity, higher Prior Beliefs of Success, and comparable Learning Rates. Furthermore, Risk Propensity was positively associated with IQ across groups. Linear models predicting Risk Propensity revealed 2 interactions: 1 between group and Perceived Risk, and 1 between IQ and Perceived Risk. Specifically, in both the SZ group and individuals with below median IQ, lower Perceived Risks was related to lower Risk Propensity. Thus, lower perception of financial risks was associated with a less advantageous pursuit of uncertain-risk rewards.

CONCLUSIONS

Findings suggest consistently decreased risk-taking on the BART in SZ may reflect risk imperception, the failure to accurately perceive and leverage relevant information to guide the advantageous pursuit of risky rewards. Additionally, our results highlight the importance of cognition in uncertain-risk decision-making.

Hasty decision making and belief inflexibility in the more delusion prone? A modified disambiguating-scenarios paradigm assessing cognitive biases implicated in delusions

INTRODUCTION

Contemporary models of psychosis imply that cognitive biases such as the jumping to conclusions (JTC), the bias against disconfirmatory evidence (BADE), and the liberal acceptance (LA) bias play a role in the pathogenesis of delusions. Most of the studies investigating the role of cognitive biases, however, have been conducted with socially neutral or abstract stimuli and have assessed patients with established psychoses. For the present study, we aimed to concurrently investigate multiple biases (i.e., the JTC, BADE, and LA biases) in a community sample with a new paradigm using more socially engaging stimuli.

METHODS

A large sample of participants (N = 874) recruited via Amazon Mechanical Turk was subdivided into two groups based on the frequency of their psychotic-like experiences (PLEs) according to the positive subscale score of the Community Assessment of Psychic Experiences (CAPE) and matched based on major demographics variables, resulting in two equally sized groups called High-PLE (at least 2 SD above the mean) and Low-PLE (maximum 0.5 above the mean; n = 46 for each group). Using a modified version of the written-scenarios BADE task, which emphasized social interactions between agents embedded in the scenario, participants rated the plausibility of response options in the face of new information.

RESULTS

In line with previous findings, the High-PLE group demonstrated the JTC, BADE, and LA biases. That is, the members of this group made more decisions after the initial piece of information, were less likely to revise their beliefs in light of new information, and provided higher plausibility ratings for implausible response options compared to the Low-PLE group.

CONCLUSIONS

Results corroborate prior findings suggesting that the JTC, BADE, and LA biases may be contributing factors in delusional ideation and that metacognitive biases extend to social situations.

Reasoning biases and delusional ideation in the general population: A longitudinal study

BACKGROUND

Reasoning biases have been suggested as risk factors for delusional ideation in both patients and non-clinical individuals. Still, it is unclear how these biases are longitudinally related to delusions in the general population. We hence aimed to investigate longitudinal associations between reasoning biases and delusional ideation in the general population.

METHODS

We conducted an online cohort study with 1184 adults from the German and Swiss general population. Participants completed measures on reasoning biases (jumping-to-conclusion bias [JTC], liberal acceptance bias [LA], bias against disconfirmatory evidence [BADE], possibility of being mistaken [PM]) and delusional ideation at baseline, and delusional ideation 7 to 8 months later.

RESULTS

A greater JTC bias was associated with a greater increase in delusional ideation over the following months. This association was better described by a positive quadratic relationship. Neither BADE, LA nor PM were associated with subsequent changes in delusional ideation.

CONCLUSIONS

This study suggests that jumping-to-conclusions predicts delusional ideation in the general population but that this association may follow a quadratic trajectory. While no other associations turned significant, future studies with shorter temporal distances may shed further light on the role of reasoning biases as risk factors for delusional ideation in non-clinical samples.

Bayesian reasoning with emotional material in patients with schizophrenia

Delusions are one of the most classical symptoms described in schizophrenia. However, despite delusions are often emotionally charged, they have been investigated using tasks involving non-affective material, such as the Beads task. In this study we compared 30 patients with schizophrenia experiencing delusions with 32 matched controls in their pattern of responses to two versions of the Beads task within a Bayesian framework. The two versions of the Beads task consisted of one emotional and one neutral, both with ratios of beads of 60:40 and 80:20, considered, respectively, as the “difficult” and “easy” variants of the task. Results indicate that patients showed a greater deviation from the normative model, especially in the 60:40 ratio, suggesting that more inaccurate probability estimations are more likely to occur under uncertainty conditions. Additionally, both patients and controls showed a greater deviation in the emotional version of the task, providing evidence of a reasoning bias modulated by the content of the stimuli. Finally, a positive correlation between patients’ deviation and delusional symptomatology was found. Impairments in the 60:40 ratio with emotional content was related to the amount of disruption in life caused by delusions. These results contribute to the understanding of how cognitive mechanisms interact with characteristics of the task (i.e., ambiguity and content) in the context of delusional thinking. These findings might be used to inform improved intervention programs in the domain of inferential reasoning.

Whodunit - A novel video-based task for the measurement of jumping to conclusions in the schizophrenia spectrum

Jumping to conclusions (JTC) is implicated in the formation and maintenance of the positive symptoms of psychosis and over the years has become a prominent treatment target. Yet, measures designed to detect JTC are compromised by a number of limitations. We aimed to address some of these shortcomings with a new video-based "Whodunit task" among participants scoring high and low on the Community Assessment of Psychic Experiences (CAPE). We recruited a large sample (N = 979) from the general population who were divided into subgroups high vs. low on psychotic-like experiences (PLE), matched for depression and background characteristics. In the Whodunit task, participants were asked to rate the likelihood that one out of six suspects was the perpetrator of a crime (deliberately ambiguous with no clear clues until the end). The primary measure was the number of sequences-to-decision (STD). In line with the hypothesis, participants scoring high on the CAPE positive subscale displayed significantly lower STD and a higher rate of JTC. Response confidence in the assessments was elevated in the PLE-High group. The number of overall decisions was also significantly elevated for the PLE-High group. No group differences were found when comparing those scoring high versus low on depression. The STD index correlated significantly with a corresponding index from another JTC task. The study presents a new paradigm for the measurement of data gathering in the schizophrenia spectrum. Speaking to its validity, the Whodunit task was correlated with another JTC measure. Future research should test abbreviated versions of the paradigm, preferably using multiple trials with differing topics/emotional themes.

People with schizophrenia use less information to interpret ambiguous social situations

BACKGROUND AND OBJECTIVES

The tendency of people with schizophrenia to gather insufficient information before making decisions or jumping to conclusions has been repeatedly reported. However, criticism has also been expressed regarding the ecological validity of this finding. Here we present the results obtained by a group of people with schizophrenia and a control group in a non-probabilistic task that requires obtaining items of information before interpreting an ambiguous social situation.

METHODS

Patients with schizophrenia (n = 48) and controls (n = 44) aged 18-50 years participated in the study. All subjects completed the Beads Task and the modified Social Information Preference Task.

RESULTS

Patients with schizophrenia showed a statistically significant tendency to jump to conclusions, including in the proposed novel social task. Unlike other studies, we were unable to find a relationship between this bias and greater severity of psychotic symptoms.

LIMITATIONS

We did not include patients with high levels of psychotic symptoms or a clinical control group.

CONCLUSIONS

The tendency to jump to conclusions in schizophrenia could be present in everyday interpersonal situations.

The relationship between early symptom severity, improvement and remission in first episode psychosis with jumping to conclusions

It is suggested that Jumping To Conclusions (JTC) reasoning bias might contribute to the distortion of external reality. However, the association between psychotic manifestations and JTC is obscure, especially if general intelligence is considered as a mediator. The aim of this study is to investigate the relation between severity, early clinical improvement and remission of symptoms in First Episode Psychosis (FEP) with JTC as an explanatory factor. One hundred seventy-one FEP individuals were evaluated with the Positive and Negative Syndrome Scale (PANSS) at baseline and one month after treatment initiation. Clinical improvement was ascribed as symptom change one-month post-baseline measurements. Symptomatic remission was assessed with the Andreasen severity criteria and JTC with the Beads Task, operationalized through Draws To Decision (DTD) (the lower the number of DTD, the higher the JTC bias). Regarding symptoms severity, total psychotic, total positive psychotic, and hallucinations-item PANSS scores showed a negative association with JTC after controlling for IQ. Regarding early clinical improvement, the association with JTC was non-significant. No significant association was detected between one month remission status of FEP and JTC. Our findings indicate that severity of positive symptoms is not associated with hastiness in decision-making, but rather with a heightened conservatism in terms of increased data gathering. Further research is required to replicate the results and clarify the cognitive processes involved.

Coronavirus conspiracy beliefs in the German-speaking general population: endorsement rates and links to reasoning biases and paranoia

BACKGROUND

Coronavirus-related conspiracy theories (CT) have been found to be associated with fewer pandemic containment-focused behaviors. It is therefore important to evaluate associated cognitive factors. We aimed to obtain first endorsement rate estimates of coronavirus-related conspiracy beliefs in a German-speaking general population sample and investigate whether delusion-related reasoning biases and paranoid ideation are associated with such beliefs.

METHODS

We conducted a cross-sectional non-probability online study, quota-sampled for age and gender, with 1684 adults from Germany and German-speaking Switzerland. We assessed general and specific coronavirus conspiracy beliefs, reasoning biases [jumping-to-conclusions bias (JTC), liberal acceptance bias (LA), bias against disconfirmatory evidence (BADE), possibility of being mistaken (PM)], and paranoid ideation, using established experimental paradigms and self-report questionnaires.

RESULTS

Around 10% of our sample endorsed coronavirus-related CT beliefs at least strongly, and another 20% to some degree. Overall endorsement was similar to levels observed in a UK-based study (Freeman et al., 2020b). Higher levels of conspiracy belief endorsement were associated with greater JTC, greater LA, greater BADE, higher PM, and greater paranoid ideation. Associations were mostly small to moderate and best described by non-linear relationships.

CONCLUSIONS

A noticeable proportion of our sample recruited in Germany and German-speaking Switzerland endorsed coronavirus conspiracy beliefs strongly or to some degree. These beliefs are associated with reasoning biases studied in delusion research. The non-probability sampling approach limits the generalizability of findings. Future longitudinal and experimental studies investigating conspiracy beliefs along the lines of reasoning are encouraged to validate reasoning aberrations as risk factors.

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.

Problems in measuring the JTC-bias in patients with psychotic disorders with the fish task: a secondary analysis of a baseline assessment of a randomized controlled trial

BACKGROUND

The jumping to conclusions bias (JTC) is considered to be an important causal factor in theoretical models for the formation and maintenance of delusions. However, recent meta-analytic findings show a rather equivocal pattern of results regarding associations between JTC and delusions. Thus, the present study aims to investigate in a large sample whether the JTC-bias is more pronounced in patients with psychotic disorders in comparison to controls and whether the JTC bias is associated with a more severe delusional conviction, persecutory delusions, and positive symptoms in general.

METHODS

Patients with psychotic disorders (n = 300) enrolled in a therapy trial and healthy controls (n = 51) conducted a variant of the beads task (fish task) as a measure for the JTC-bias at the start of the trial. Further, clinical interviews were used to assess patients' delusional severity and delusional conviction.

RESULTS

There were no statistically significant differences between patients with psychotic disorders (with 53% displaying the JTC-bias) and controls (41%). Furthermore, there were no statistically significant correlations between JTC measures and persecutory delusions, delusional conviction, and positive symptoms.

CONCLUSIONS

We found no differences in JTC between patients with psychotic disorders and healthy controls, which is in part in line with meta-analytic findings using a wide range of JTC task variants. Interestingly, patients with psychotic disorders displayed JTC rates commonly found in the literature, while healthy control subjects showed an unexpectedly high level of JTC. The task variant we used in the present study (fish task) is discussed as a potential reason for our results, as it may induce a more deliberative reasoning style in controls as compared to the traditional beads task. Furthermore, possible implications for the measurement of the JTC-bias, in general, are discussed.

TRIAL REGISTRATION

ISRCTN29242879 ( isrctn.com ), date of registration: April 12th 2006, retrospectively registered.

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.

Jumping to conclusions in the less-delusion-prone? Preliminary evidence from a more reliable beads task

BACKGROUND AND OBJECTIVES

Several meta-analyses have shown that people with psychosis tend to gather less information (i.e., they make fewer draws to decision, or DTD) on the beads task than healthy controls. A single meta-analysis has also found a small negative association between delusion-proneness and DTD in healthy samples, but with considerable heterogeneity.

METHODS

We used the new and more reliable "distractor sequences" beads task to clarify the nature of the relationship between delusion-proneness and DTD in a healthy sample. Healthy participants (N = 203) completed the distractor sequences beads task and the Peters Delusions Inventory (PDI), which measures delusion-proneness.

RESULTS

PDI and DTD were positively correlated, and those who jumped to conclusions (DTD ≤ 2) had lower PDI than those who did not. Comparing PDI quartiles on DTD provided some evidence the positive association did not extend to the highest PDI quartile. We found that DTD and delusion-proneness were positively related in our non-clinical sample, which was unexpected.

LIMITATIONS

Results need replication with a clinical sample.

CONCLUSIONS

Considering the well-established association between the JTC bias and clinical delusions, the current finding may reflect a relationship that differs between non-clinical and clinically significant delusional groups, or one which reverses sign at some level of delusion-proneness.

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.

Prolonged rather than hasty decision-making in schizophrenia using the box task. Must we rethink the jumping to conclusions account of paranoia?

Jumping to conclusions (JTC) is the best established cognitive bias in schizophrenia and is increasingly targeted in interventions aimed to improve positive symptoms. To address shortcomings of the standard measure to capture JTC, the beads task, we developed a new variant-the box task-which was subsequently validated in people with elevated psychotic-like experiences. For the first time, the box task was administered in a sample of individuals with manifest schizophrenia. We hypothesized that patients with schizophrenia would display an elevated JTC bias relative to controls.

METHOD

We recruited a large sample of 101 patients with schizophrenia and matched them to an online sample recruited from the general population. In the box task, participants must decide which of two kinds of colored balls are presented more often. Participants are told that the task may end prematurely, and that task performance will be counted as an error if no decision had been made before that point. The primary measure was the number of draws to decision (DTD), where fewer DTD corresponds to greater JTC.

RESULTS

In contrast to expectations, participants with schizophrenia showed significantly higher DTD (i.e., reduced JTC). Consistent with our previous findings, patients also displayed a lowered decision threshold compared to controls. Response confidence for the final decision was lower in patients and correlated with self-esteem and positive symptoms. While there was evidence that previous knowledge of the box task lowered DTD, exclusion of participants with experience on the box task did not substantially change results.

DISCUSSION

The study fits a growing body of experiments casting doubt on the generalizability of the JTC effect in schizophrenia across different tasks. While the study tentatively supports a liberal acceptance account of psychosis, caution is warranted and we recommend that research should explore and control for potentially important mediators (e.g., task difficulty, stress, test-taking attitudes).

Risky decision-making and delusion proneness: An initial examination

Delusion proneness is an individual-differences characteristic, existing on a continuum from no delusional thoughts to a diagnosis of schizophrenia. Previous research found individuals high in delusion proneness request less information to make decisions, potentially making a decision without sufficient information (jumping to conclusions). The present study examined risky decision-making as a function of delusion proneness. Participants (n = 102) completed the Peters Delusions Inventory to assess delusion proneness, and the Iowa Gambling Task (IGT) and Game of Dice Task (GDT) to assess risky decision-making. Although no significant results emerged on the GDT, those scoring higher in delusion proneness decided more advantageously on the IGT than those scoring lower in delusion proneness. Exploratory analyses indicated no significant relationship between gender and task performance. The present study provides further insight into risky decision making as a function of delusion proneness.

Jumping to conclusions in persistent pain using a somatosensory modification of the beads task

BACKGROUND

There is theoretical and empirical evidence that persistent pain occurs because of a distortion in top-down perceptual processes. 'Jumping to conclusions' (JTC) tasks, such as the beads task, purportedly capture these processes and have yet to be studied in people with chronic pain. However, the beads task uses visual stimuli, whereas tasks involving processing in the somatosensory domain seem at least more face valid in this population. This study uses a novel somatosensory adaptation of the beads task to explore whether a JTC reasoning style is more common in people with persistent pain compared controls.

METHODS

30 persistent pain patients and 30 age-, gender- and education-matched controls completed the visual beads JTC task and a novel somatosensory version of the JTC task that used tactile stimuli (vibrations to the fingertip).

FINDINGS

Patients with persistent pain showed a 'jumping to conclusions' reasoning style on both tasks compared to the control group and there was no significant difference in the effect sizes on the two tasks.

INTERPRETATION

This preliminarily study demonstrated that individuals with persistent pain show a JTC reasoning style to both visual and somatosensory stimuli. Future research should focus on establishing how or whether this bias directly influences the experience of persistent pain.

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.

Examining reasoning biases in schizophrenia using a modified "Jumping to Conclusions" probabilistic reasoning task

Although the Jumping To Conclusion (JTC) bias has been extensively studied in relation to schizophrenia and persecutory delusions, the relationship between JTC and other reasoning biases implicated in delusional ideation is not fully understood. We modified the traditional JTC task to assess co-occurrence of reasoning biases in decision making. Forty-six patients with schizophrenia and 46 healthy controls completed two versions [neutral colored beads and salient comments] of the modified task. We replicated previous findings indicating that patients showed a greater JTC bias, and in both groups, the JTC bias was more pronounced for the salient task. However, we observed a significant effect for non-Bayesian judgments, indicating that patients showed greater difficulty in probabilistic reasoning. When controlling for probabilistic reasoning ability, the observed JTC bias effects were diminished. Our findings that faulty probability assessment accounts for the JTC bias indicates that the traditional JTC bias task may not represent an inherent hasty decision-making bias, but rather an inability to fully understand and execute the stated goals of the task. These results call into question the current understanding of the JTC bias and the independence of this bias apart from the cognitive demands of the task.

Are Psychotic Experiences Related to Poorer Reflective Reasoning?

Background: Cognitive biases play an important role in the formation and maintenance of delusions. These biases are indicators of a weak reflective mind, or reduced engaging in reflective and deliberate reasoning. In three experiments, we tested whether a bias to accept non-sense statements as profound, treat metaphorical statements as literal, and suppress intuitive responses is related to psychotic-like experiences.

Methods: We tested deliberate reasoning and psychotic-like experiences in the general population and in patients with a former psychotic episode. Deliberate reasoning was assessed with the bullshit receptivity scale, the ontological confabulation scale and the cognitive reflection test (CRT). We also measured algorithmic performance with the Berlin numeracy test and the wordsum test. Psychotic-like experiences were measured with the Community Assessment of Psychic Experience (CAPE-42) scale.

Results: Psychotic-like experiences were positively correlated with a larger receptivity toward bullshit, more ontological confabulations, and also a lower score on the CRT but not with algorithmic task performance. In the patient group higher psychotic-like experiences significantly correlated with higher bullshit receptivity.

Conclusion: Reduced deliberate reasoning may contribute to the formation of delusions, and be a general thinking bias largely independent of a person's general intelligence. Acceptance of bullshit may be facilitated the more positive symptoms a patient has, contributing to the maintenance of the delusions.

A Bayesian perspective on delusions: Suggestions for modifying two reasoning tasks

BACKGROUND AND OBJECTIVES

There are a range of mechanistic explanations on the formation and maintenance of delusions. Within the Bayesian brain hypothesis, particularly within the framework of predictive coding models, delusions are seen as an aberrant inference process characterized by either a failure in sensory attenuation or an aberrant weighting of prior experience. Testing of these Bayesian decision theories requires measuring of both the patients' confidence in their beliefs and the confidence they assign new, incoming information. In the Bayesian framework we apply here, the former is referred to as the prior while the latter is usually called the data or likelihood.

METHODS AND RESULTS

This narrative review will commence by giving an introduction to the basic concept underlying the Bayesian decision theory approach to delusion. A consequence of crucial importance of this sketch is that it provides a measure for the persistence of a belief. Experimental tasks measuring these parameters are presented. Further, a modification of two standard reasoning tasks, the beads task and the evidence integration task, is proposed that permits testing the parameters from Bayesian decision theory.

LIMITATIONS

Patients differ from controls by the distress the delusions causes to them. The Bayesian Decision theory framework has no explicit parameter for distress.

CONCLUSIONS

A more detailed reporting of differences between patients with delusions is warranted.

A two-stage cognitive theory of the positive symptoms of psychosis. Highlighting the role of lowered decision thresholds

OBJECTIVES

We outline a two-stage heuristic account for the pathogenesis of the positive symptoms of psychosis.

METHODS

A narrative review on the empirical evidence of the liberal acceptance (LA) account of positive symptoms is presented.

HYPOTHESIS

At the heart of our theory is the idea that psychosis is characterized by a lowered decision threshold, which results in the premature acceptance of hypotheses that a nonpsychotic individual would reject. Once the hypothesis is judged as valid, counterevidence is not sought anymore due to a bias against disconfirmatory evidence as well as confirmation biases, consolidating the false hypothesis. As a result of LA, confidence in errors is enhanced relative to controls. Subjective probabilities are initially low for hypotheses in individuals with delusions, and delusional ideas at stage 1 (belief formation) are often fragile. In the course of the second stage (belief maintenance), fleeting delusional ideas evolve into fixed false beliefs, particularly if the delusional idea is congruent with the emotional state and provides "meaning". LA may also contribute to hallucinations through a misattribution of (partially) normal sensory phenomena. Interventions such as metacognitive training that aim to "plant the seeds of doubt" decrease positive symptoms by encouraging individuals to seek more information and to attenuate confidence. The effect of antipsychotic medication is explained by its doubt-inducing properties.

LIMITATIONS

The model needs to be confirmed by longitudinal designs that allow an examination of causal relationships. Evidence is currently weak for hallucinations.

CONCLUSIONS

The theory may account for positive symptoms in a subgroup of patients. Future directions are outlined.

Negative affect and a fluctuating jumping to conclusions bias predict subsequent paranoia in daily life: An online experience sampling study

BACKGROUND AND OBJECTIVES

Negative affect and a tendency to "jump to conclusions" (JTC) are associated with paranoia. So far, only negative affect has been examined as a precursor of subsequent paranoia in daily life using experience sampling (ESM). We addressed this research gap and used ESM to test whether JTC fluctuates in daily life, whether it predicts subsequent paranoia, and whether it mediates the effect of negative affect on paranoia.

METHODS

Thirty-five participants with schizophrenia spectrum disorders repeatedly self-reported negative affect, JTC, and paranoia via online questionnaires on two consecutive days. We measured JTC with a paradigm consisting of ambiguous written scenarios. Multilevel linear models were conducted.

RESULTS

Most participants showed JTC consistently on two days rather than only on one day. When time was used as a predictor of JTC, significant slope variance indicated that for a subgroup of participants JTC fluctuated over time. For 48% of participants, these fluctuations equaled changes of approximately ±1 point on the four-point JTC scale within one day. There was no mediation. However, negative affect and JTC both significantly predicted subsequent paranoia.

LIMITATIONS

The ESM assessment period was short and encompassed few assessments (8 in total).

CONCLUSIONS

Our findings indicate that JTC is both stable (regarding its mere occurrence) and fluctuating simultaneously (regarding its magnitude). Although JTC was not a mediator linking negative affect and paranoia, it did predict paranoia. Further ESM studies on JTC are needed to confirm our findings in longer assessment periods and with other JTC paradigms.

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.

Psychotic Experiences and Overhasty Inferences Are Related to Maladaptive Learning

Theoretical accounts suggest that an alteration in the brain’s learning mechanisms might lead to overhasty inferences, resulting in psychotic symptoms. Here, we sought to elucidate the suggested link between maladaptive learning and psychosis. Ninety-eight healthy individuals with varying degrees of delusional ideation and hallucinatory experiences performed a probabilistic reasoning task that allowed us to quantify overhasty inferences. Replicating previous results, we found a relationship between psychotic experiences and overhasty inferences during probabilistic reasoning. Computational modelling revealed that the behavioral data was best explained by a novel computational learning model that formalizes the adaptiveness of learning by a non-linear distortion of prediction error processing, where an increased non-linearity implies a growing resilience against learning from surprising and thus unreliable information (large prediction errors). Most importantly, a decreased adaptiveness of learning predicted delusional ideation and hallucinatory experiences. Our current findings provide a formal description of the computational mechanisms underlying overhasty inferences, thereby empirically substantiating theories that link psychosis to maladaptive learning.

Predictive coding theories represent a unifying account of psychosis, stating that the central psychosis-related alteration affects the interplay between prior predictions and incoming information. Since every incoming information is imprecise and potentially allows for different interpretations, prior expectations achieve the enforcement of interpretations with a higher prior probability. Disturbances in this basic framework might let unlikely interpretations come into effect, resulting in proneness for delusions and hallucinations. Here, we contribute to these theories by devising a novel computational model for behavior in a reasoning task that quantifies the participants' readiness to draw inferences from very surprising information. We thereby demonstrate that precisely this increased learning from surprising and thus potentially spurious information, as opposed to non-specific alterations in the general learning speed, predispose healthy individuals for delusions and hallucinations. The present results hence speak for the hypothesis that hallucinations and delusions arise when noisy information is considered as precise and is thus not suppressed by opposing prior beliefs. In this sense, our findings also tie with recent neurophysiological models of psychosis that posit aberrations in modulatory neurotransmitters such as dopamine (or its interactions with GABAergic interneurons) as a correlate of perturbed computations of information precision in the cortex.

Subjective versus objective cognition: Evidence for poor metacognitive monitoring in schizophrenia

BACKGROUND

Patients with schizophrenia display a number of cognitive biases, particularly a tendency to jump to conclusions, which are implicated in the pathogenesis of the disorder. The present study contrasted the degree of objective reasoning biases with subjective cognitive insight. We expected that patients with schizophrenia would display greater objective than subjective impairment suggestive of poor metacognitive awareness.

METHODS

Patients with schizophrenia (n=140) and healthy controls (n=60) underwent a test battery encompassing a cognitive bias paradigm (beads task) as well as neurocognitive tests (story recall, trail-making tests). In addition, they were administered the Beck Cognitive Insight Scale (BCIS), a subjective measure of (meta)cognitive awareness.

RESULTS

Corroborating prior research on decision making, draws to decisions were significantly delayed in controls relative to patients, whereas the core jumping to conclusion parameter (i.e., decision after one or two pieces of information) bordered significance. Patients with schizophrenia showed a lowered decision threshold and impaired neurocognition relative to nonclinical controls. Despite poor cognitive performance and prior psychotic episodes, patients with schizophrenia showed similar scores on the self-confidence subscale of the BCIS and reported even higher levels of self-reflectiveness relative to healthy controls.

DISCUSSION

The study demonstrates that patients with schizophrenia show severe cognitive biases and neurocognitive deficits but display only partial awareness herein. Raising cognitive insight in a non-insulting fashion and elevating patients' corrigibility as well as willingness to consider others' feedback and advice may help to narrow this gap and improve psychiatric symptomatology.