Bias Against Disconfirmatory Evidence Research Articles

Impaired belief revision yet intact information seeking in positive schizotypy: A modified task of bias against disconfirmatory evidence

Cognitive models of delusions emphasize the role of bias against disconfirmatory evidence (BADE) in maintaining false beliefs, but sources of this tendency remain elusive. While impaired information integration could be an explanation for this tendency, the lack of information seeking motive could also result in disregard for new evidence once a (false) belief is formed. The role of information seeking in the association between psychosis-proneness and belief inflexibility has not been investigated in the context of a social interpretation task. In this study, we modified the Interpretation Inflexibility Task (IIT), which assess bias against disconfirmatory evidence in interpersonal contexts, to permit assessment of information seeking by allowing participants to skip seeing increasingly disambiguating information (in the form of pictures at varying degrees of degradation). A robust regression analysis was conducted to examine whether increasing severity of positive schizotypy is associated with more frequent skipping of later trial stages, to examine information seeking. Controlling for the number of pictures seen by participants, a robust mixed effects analysis was conducted to investigate the associations of positive schizotypy, trait anxiety, and the emotional valence of the scenario with a measure of belief revision. Participants higher in positive schizotypy did not opt out of seeing disambiguating information more frequently, p = 0.65, ß = 0.04; despite this, they still exhibited heightened belief inflexibility by rating the lures and true explanations as equally plausible, p < 0.001, ß = -0.32. These results suggest that bias against disconfirmatory evidence in positive schizotypy is unlikely a result of reduced information seeking, leaving impaired information integration as a more likely source.

Are depressive symptoms linked to a reduced pupillary response to novel positive information?-An eye tracking proof-of-concept study.

Depressive symptoms have been linked to difficulties in revising established negative beliefs in response to novel positive information. Recent predictive processing accounts have suggested that this bias in belief updating may be related to a blunted processing of positive prediction errors at the neural level. In this proof-of-concept study, pupil dilation in response to unexpected positive emotional information was examined as a psychophysiological marker of an attenuated processing of positive prediction errors associated with depressive symptoms. Participants (N = 34) completed a modified version of the emotional Bias Against Disconfirmatory Evidence (BADE) task in which scenarios initially suggest negative interpretations that are later either confirmed or disconfirmed by additional information. Pupil dilation in response to the confirmatory and disconfirmatory information was recorded. Behavioral results showed that depressive symptoms were related to difficulties in revising negative interpretations despite disconfirmatory positive information. The eye tracking results pointed to a reduced pupil response to unexpected positive information among people with elevated depressive symptoms. Altogether, the present study demonstrates that the adapted emotional BADE task can be appropriate for examining psychophysiological aspects such as changes in pupil size along with behavioral responses. Furthermore, the results suggest that depression may be characterized by deviations in both behavioral (i.e., reduced updating of negative beliefs) and psychophysiological (i.e., decreased pupil dilation) responses to unexpected positive information. Future work should focus on a larger sample including clinically depressed patients to further explore these findings.

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

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. 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. 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. 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.

Relationships between cognitive biases, decision-making, and delusions

Multiple measures of decision-making under uncertainty (e.g. jumping to conclusions (JTC), bias against disconfirmatory evidence (BADE), win-switch behavior, random exploration) have been associated with delusional thinking in independent studies. Yet, it is unknown whether these variables explain shared or unique variance in delusional thinking, and whether these relationships are specific to paranoia or delusional ideation more broadly. Additionally, the underlying computational mechanisms require further investigation. To investigate these questions, task and self-report data were collected in 88 individuals (46 healthy controls, 42 schizophrenia-spectrum) and included measures of cognitive biases and behavior on probabilistic reversal learning and explore/exploit tasks. Of those, only win-switch rate significantly differed between groups. In regression, reversal learning performance, random exploration, and poor evidence integration during BADE showed significant, independent associations with paranoia. Only self-reported JTC was associated with delusional ideation, controlling for paranoia. Computational parameters increased the proportion of variance explained in paranoia. Overall, decision-making influenced by strong volatility and variability is specifically associated with paranoia, whereas self-reported hasty decision-making is specifically associated with other themes of delusional ideation. These aspects of decision-making under uncertainty may therefore represent distinct cognitive processes that, together, have the potential to worsen delusional thinking across the psychosis spectrum.

Belief Inflexibility and Cognitive Biases in Anorexia Nervosa-The Role of the Bias against Disconfirmatory Evidence and Its Clinical and Neuropsychological Correlates.

The aim of this study was to explore, in a sample of patients with a diagnosis of AN, the ability to question their first impression and, in particular, the willingness to integrate their prior ideas and thoughts with additional progressive incoming information. A total of 45 healthy women and 103 patients with a diagnosis of AN, consecutively admitted to the Eating Disorder Padova Hospital-University Unit, underwent a broad clinical and neuropsychological assessment. All participants were administered the Bias Against Disconfirmatory Evidence (BADE) task, which specifically investigates belief integration cognitive bias. Acute AN patients showed a significantly greater bias toward disconfirming their previous judgment, in comparison to healthy women (BADE score, respectively, 2.5 ± 2.0 vs. 3.3 ± 1.6; Mann-Whitney test, p = 0.012). A binge-eating/purging subtype of AN individuals, compared to restrictive AN patients and controls, showed greater disconfirmatory bias and also a significant propensity to uncritically accept implausible interpretations (BADE score, respectively, 1.55 ± 1.6 and 2.70 ± 1.97 vs. 3.33 ± 1.63; Kruskal-Wallis test, p = 0.002 and liberal acceptance score, respectively, 1.32 ± 0.93 and 0.92 ± 1.21 vs. 0.98 ± 0.75; Kruskal-Wallis test p = 0.03). Abstract thinking skills and cognitive flexibility, as well as high central coherence, are neuropsychological aspects positively correlated with cognitive bias, in both patients and controls. Research into belief integration bias in AN population could enable us to shed light on hidden dimensional aspects, facilitating a better understanding of the psychopathology of a disorder that is so complex and difficult to treat.

COVID-19 conspiracy ideation is associated with the delusion proneness trait and resistance to update of beliefs

The rapid spread of conspiracy ideas associated with the recent COVID-19 pandemic represents a major threat to the ongoing and coming vaccination programs. Yet, the cognitive factors underlying the pandemic-related conspiracy beliefs are not well described. We hypothesized that such cognitive style is driven by delusion proneness, a trait phenotype associated with formation of delusion-like beliefs that exists on a continuum in the normal population. To probe this hypothesis, we developed a COVID-19 conspiracy questionnaire (CCQ) and assessed 577 subjects online. Their responses clustered into three factors that included Conspiracy, Distrust and Fear/Action as identified using principal component analysis. We then showed that CCQ (in particular the Conspiracy and Distrust factors) related both to general delusion proneness assessed with Peter’s Delusion Inventory (PDI) as well as resistance to belief update using a Bias Against Disconfirmatory Evidence (BADE) task. Further, linear regression and pathway analyses suggested a specific contribution of BADE to CCQ not directly explained by PDI. Importantly, the main results remained significant when using a truncated version of the PDI where questions on paranoia were removed (in order to avoid circular evidence), and when adjusting for ADHD- and autistic traits (that are known to be substantially related to delusion proneness). Altogether, our results strongly suggest that pandemic-related conspiracy ideation is associated with delusion proneness trait phenotype.

Can you change your mind? An ERP study of cognitive flexibility and new evidence integration

Cognitive flexibility is an ability that allows individuals to integrate external evidence into previous expectancies. Individual differences in this ability were examined using Event-Related Potentials (ERPs), focusing on the fact that new evidence can either confirm or disprove an initial impression. Written scenarios prompted to make a prediction while either confirmatory or disconfirmatory evidence followed. A final sentence presented participants with a statement congruent with the prediction likely to have been formed based on the first statement or a statement rather congruent with corrective new evidence. A Bias Against Disconfirmatory Evidence (BADE) test rated participants in cognitive flexibility. ERPs revealed that whereas individuals overall typically reacted to unexpected endings (a classical N400 effect) within the confirmatory evidence condition, higher cognitive flexibility scores were associated with smaller N400 effects. Furthermore, individuals showed larger P600s for disconfirmatory than confirmatory evidence conditions, regardless of the final target ending. This result indexes reanalysis processes whenever disconfirmatory evidence was present. Regression analysis of BADE scores and ERP effects are presented and discussed. Late ERP components are sensitive enough to detect new evidence integration capabilities and thus provide a good implicit measure of cognitive flexibility.

Resistance to Extinction of Evaluative Fear Conditioning in Delusion Proneness.

Delusional beliefs consist of strong priors characterized by resistance to change even when evidence supporting another view is overwhelming. Such bias against disconfirmatory evidence (BADE) has been experimentally demonstrated in patients with psychosis as well as in delusion proneness. In this fMRI-study, we tested for similar resistance to change and associated brain processes in extinction of fear learning, involving a well-described mechanism dependent of evidence updating. A social fear conditioning paradigm was used in which four faces had either been coupled to an unconditioned aversive stimulus (CS+) or not (CS-). For two of the faces, instructions had been given about the fear contingencies (iCS+/iCS-) while for two other faces no such instructions had been given (niCS+/niCS-). Interaction analysis suggested that individuals who score high on delusion-proneness (hDP; n = 20) displayed less extinction of evaluative fear compared to those with low delusion proneness (lDP; n = 23; n = 19 in fMRI-analysis) for non-instructed faces (F = 5.469, P = .024). The resistance to extinction was supported by a difference in extinction related activity between the two groups in medial prefrontal cortex and its connectivity with amygdala, as well as in a cortical network supporting fear processing. For instructed faces no extinction was noted, but there was a larger evaluative fear (F = 5.048, P = 0.03) and an increased functional connectivity between lateral orbitofrontal cortex and fear processing regions for hDP than lDP. Our study links previous explored BADE-effects in delusion associated phenotypes to fear extinction, and suggest that effects of instructions on evaluative fear learning are more pronounced in delusion prone subjects.

Aberrant adapting of beliefs under stress: a mechanism relevant to the formation of paranoia?

Difficulties in the ability to adapt beliefs in the face of new information are associated with psychosis and its central symptom - paranoia. As cognitive processes and psychotic symptoms are both known to be sensitive to stress, the present study investigated the exact associations between stress, adapting of beliefs [reversal learning (RL), bias against disconfirmatory evidence (BADE), and jumping to conclusions (JTC)] and paranoia. We hypothesized that paranoia would increase under stress and that difficulties in adapting of beliefs would mediate or moderate the link between stress and paranoia. Furthermore, we hypothesized that the investigated effects would be strongest in the group of individuals diagnosed with a psychotic disorder. We exposed 155 participants (38 diagnosed with a psychotic disorder, 40 individuals with attenuated psychotic symptoms, 39 clinical controls diagnosed with an obsessive-compulsive disorder, and 38 healthy controls) to a control condition and a stress condition, in which we assessed their levels of paranoia and their ability to adapt beliefs. We applied multilevel models to analyze the data. Paranoia was higher in the stress condition than in the control condition, b = 1.142, s.e. = 0.338, t(150) = 3.381, p < 0.001. RL, BADE, and JTC did not differ between conditions and did not mediate or moderate the association between stress and paranoia (all ps > 0.05). The results support the assumption that stress triggers paranoia. However, the link between stress and paranoia does not seem to be affected by the ability to adapt beliefs.

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

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. 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. 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. 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.

Inflexibility in Reasoning: Comparisons of Cognitive Flexibility, Explanatory Flexibility, and Belief Flexibility Between Schizophrenia and Major Depressive Disorder.

Introduction: Inflexibility in reasoning has been suggested to contribute to psychiatric disorders, such as explanatory flexibility in depression and belief flexibility in schizophrenia. However, studies tended to examine only one of the flexibility constructs, which could be related to each other, within a single group of patients. As enhancing flexibility in thinking has become one of the psychological treatment goals across disorders, this study aimed to examine three constructs of flexibility (cognitive flexibility, explanatory flexibility, and belief flexibility) in two psychiatric groups.Methods: We compared three groups of participants: (i) 56 outpatients with a schizophrenia-spectrum disorder and active delusions, (ii) 57 outpatients with major depressive disorder and at least a moderate level of depression, and (iii) 30 healthy controls. Participants were assessed on symptom severity and flexibility, using the Trail-Making Task, the Attributional Style Questionnaire, the Maudsley Assessment of Delusions Scale (MADS) and the Bias Against Disconfirmatory Evidence (BADE) Task.Results: Cognitive flexibility was reduced in the two clinical groups compared to controls. Explanatory flexibility was comparable across groups. The three groups differed in belief flexibility measured by MADS but not by the BADE task. Response to hypothetical contradiction was reduced in the delusion group than the other two groups, and the ability to generate alternative explanations was reduced in the delusion group than healthy controls.Discussion: We found an effect of diagnosis on cognitive flexibility, which might be confounded by differences in intellectual functioning. Reduced belief flexibility tended to be specific to delusions.

S45. EFFICACY OF A 4-SESSION METACOGNITIVE TRAINING FOR SCHIZOPHRENIA, DEPRESSION, AND BELIEF FLEXIBILITY

BackgroundMetacognitive training (MCT) was developed to increase awareness of cognitive biases (Moritz & Woodward, 2007). Each of the 8 MCT modules targets a specific reasoning bias, such as bias against disconfirmatory evidence, jumping to conclusions, and attributional biases. MCT has been shown to be effective in improving delusions. However, it remains unclear to what extent specific MCT modules are effective in ameliorating the reasoning biases that they target, and whether they may also be effective for other disorders characterized by similar cognitive biases. This study aimed to compare the efficacy of a 4-week MCT on belief flexibility among patients with schizophrenia and patients with major depressive disorder (MDD).MethodsThis study adopted a single-blind randomized controlled design. Adult patients with a schizophrenia spectrum disorder (N = 56) and MDD (N = 57) were respectively randomized into MCT or treatment as usual (TAU, i.e. standard psychiatric care). The MCT intervention consisted of the following modules: ‘attributions’, ‘changing beliefs’, ‘to empathise’, and ‘self-esteem and mood’. Patients were assessed at pre-treatment, post-treatment, 1-month and 6-month follow-ups. Belief flexibility was measured using the Maudsley Assessment of Delusions Scale (MADS) and the Bias Against Disconfirmatory Evidence (BADE) task (Wessely et al, 1993; Woodward et al, 2006).ResultsAmong the 113 participants, 27 patients with schizophrenia and 29 patients with MDD attended the 4-week MCT. For the schizophrenia arm, repeated-measures ANOVA revealed significant improvements in PANSS total score (p < .001, d = 0.87) and PSYRATS delusions score (p = .001, d = 0.69) after MCT. These treatment effects sustained at 1-month follow-up (ps < .01), and improvement in delusions sustained at 6 months (ps < .05). Mixed-design ANOVAs revealed that improvements in PANSS total score (ps < .05) and PSYRATS delusions score (ps < .01) on the MCT condition were significantly greater than TAU over the corresponding timeframes. McNemar tests revealed that one of the MADS measures, reaction to hypothetical contradiction (RTHC), improved after MCT (p = .004), and sustained at 1 month (p = 0.016) and 6 months (p = 0.002). There was no change in belief flexibility across timepoints on the TAU condition. Change in RTHC following MCT was not significantly greater than TAU. Symptom changes were not predicted by any of the belief flexibility variables.For the MDD arm, repeated-measures ANOVA revealed significant improvement in Beck Depression Inventory (BDI-II) (p < .001, d = 1.45) after MCT, which sustained at 1-month and 6-month follow-up (ps < .01). Mixed-design ANOVAs revealed that improvements in BDI-II on the MCT condition were significantly greater than TAU over the corresponding timeframes (ps < .001). Repeated-measures ANOVA revealed that evidence integration (EI) improved after MCT (d = 0.57) and sustained at 1 month (p = 0.042) and 6 months (p = 0.041). There was no change in belief flexibility across timepoints on the TAU condition. Change in EI following MCT was not significantly greater than TAU. Symptom change was not predicted by any of the belief flexibility variables.DiscussionWe found large and persistent effects of reduction in delusions and depression, following a 4-week MCT, in two clinical groups. There is preliminary evidence that belief flexibility improved following MCT, although the effects were less stable and were of smaller sizes. Further research on the relationship between belief flexibility and various psychopathologies is warranted.

Stress and cognitive biases in schizotypy: A two-site study of bias against disconfirmatory evidence and jumping to conclusions

The dysfunctional cognitive and reasoning biases which underpin psychotic symptoms are likely to present prior to the onset of a diagnosable disorder and should therefore be detectable along the psychosis continuum in individuals with schizotypal traits. Two reasoning biases, Bias Against Disconfirmatory Evidence (BADE) and Jumping to Conclusions (JTC), describe how information is selected and weighed under conditions of uncertainty during decision making. It is likely that states such as elevated stress exacerbates JTC and BADE in individuals with high schizotypal traits vulnerable to displaying these information gathering styles. Therefore, we evaluated whether stress and schizotypy interacted to predict these reasoning biases using separate samples from the US (JTC) and England (BADE). Generally speaking, schizotypal traits and stress were not independently associated with dysfunctional reasoning biases. However, across both studies, the interaction between schizotypy traits and stress significantly predicted reasoning biases such that increased stress was associated with increased reasoning biases, but only for individuals low in schizotypal traits. These patterns were observed for positive schizotypal traits (in both samples), for negative traits (in the England sample only), but not for disorganization traits. For both samples, our findings suggest that the presence of states such as stress is associated with, though not necessarily dysfunctional, reasoning biases in individuals with low schizotypy. These reasoning biases seemed, in some ways, relatively immutable to stress in individuals endorsing high levels of positive schizotypal traits.

The relationship between anomalistic belief and biases of evidence integration and jumping to conclusions

Biases in the assessment and integration of evidence are likely contributors to anomalistic (e.g., paranormal, extra-terrestrial) beliefs because of the non-evidence based nature of these beliefs. However, little research has examined the relationship between anomalistic beliefs and evidence integration biases. The current study addressed this gap by examining the relationship between anomalistic belief and four such biases; bias against disconfirmatory evidence (BADE), bias against confirmatory evidence (BACE), liberal acceptance bias, and the jumping to conclusions bias (JTC). Standard BADE scenarios were used to measure BADE, BACE, and the liberal acceptance bias: Participants were given three pieces of evidence, one at a time, and required to rate several alternative explanations. The JTC was measured using two draws-to-decisions tasks (beads and emotionally salient), and participants also completed measures of anomalistic belief and delusion-proneness. Results showed that liberal acceptance was the only evidence integration bias that significantly predicted greater overall anomalistic belief. However, this relationship was no longer significant once delusion proneness was controlled for. Additionally, BADE significantly predicted experiential (but not other types of) anomalistic beliefs even after controlling for delusion proneness. We propose that liberal acceptance may lead people to form anomalistic beliefs on the basis of little evidence, and that stronger BADE may make these beliefs highly resistant to change.

Psychotic Symptoms Predicting Evidence Integration in Schizophrenia

Abstract. A bias against disconfirmatory evidence (BADE) is a cognitive bias associated with delusions in schizophrenia. Previous studies reporting an association between reduced evidence integration and delusions used a single measure of delusion severity, typically to form patient groups. In the current study we perform an exploratory analysis to investigate whether BADE is specific to delusions or extends to other symptoms of psychosis. To address this, we used constrained principal component analysis (CPCA) on four merged BADE studies on schizophrenia to explore the component structure in the BADE task measures that is predictable from symptoms. A component reflecting evidence integration emerged, and was predicted by delusions as expected, but also by thought disorder. This provides novel methodology for cognitive neuropsychiatric investigations into the underpinnings of the symptoms of schizophrenia by enabling investigators to consider a range of symptoms alongside the one that is the target of their investigation.

How Do Delusion-Prone Individuals Respond to Disconfirmatory Evidence?

Abstract. Research employing the beads task suggests that people with delusional tendencies over-adjust to disconfirmatory evidence compared to low-delusion-prone individuals. This interpretation is in tension with studies using the bias against disconfirmatory evidence (BADE) task, which provide evidence that people with delusional tendencies are less receptive to disconfirmatory evidence. It has been suggested that over-adjustment on the beads task may be driven by miscomprehension of the task. The current preliminary study aimed to minimize miscomprehension on the beads task and determine how high-delusion-prone people respond to disconfirmatory evidence on both tasks. Fifty-one undergraduate participants completed the BADE task and an adapted version of the beads task. We expected that corrective feedback on the beads task would reduce miscomprehension, and that high-delusion-prone participants would be less receptive to disconfirmatory evidence on both tasks. Our results suggest this version of the beads task improved rates of comprehension relative to previous research. However, we found no evidence that the high-delusion-prone group demonstrated elevated over-adjustment or belief inflexibility in either task. The theoretical implications of these findings are discussed.

Measuring bias against disconfirmatory evidence: An evaluation of BADE task scoring methods and the case for a novel method

Research suggests that bias against disconfirmatory evidence (BADE) may help maintain delusions in the face of overwhelming evidence against them. Much of this research has employed Woodward and colleagues’ BADE task. Different methods of scoring this task, many of which have significant drawbacks, are currently used by researchers, making it difficult to compare results across studies of BADE. Continued advancement of BADE research demands a scoring method with more favorable psychometric properties that is used more consistently by researchers. Here, we take a data-driven but theory-informed approach to the development of a new method for scoring the BADE task. This new scoring procedure is more parsimonious than previous metrics of BADE but captures the vast majority of their predictive variance in relation to delusions. This new method may therefore be capable of inspiring consensus use among BADE researchers. If so, it could significantly increase the ease of comparing future studies of BADE.

Fast and slow thinking in distressing delusions: A review of the literature and implications for targeted therapy

The recent literature on reasoning biases in psychosis and delusions is reviewed. The state-of-the-art knowledge from systematic reviews and meta-analyses on the evidence for jumping to conclusions is briefly summarised, before a fuller discussion of the more recent empirical literature on belief flexibility as applied to delusions. The methodology and evidence in relation to studies of belief flexibility and the Bias Against Disconfirmatory Evidence (BADE) across the delusional continuum will be critically appraised, and implications drawn for improving cognitive therapy. It will be proposed that dual process models of reasoning, which Kahneman (Kahneman, 2011) popularised as ‘fast and slow thinking’, provide a useful theoretical framework for integrating further research and informing clinical practice. The emergence of therapies which specifically target fast and slow thinking in people with distressing delusions will be described.

Sesgo “salto a las conclusiones” en pacientes con patología psiquiátrica

Objective: to describe the presence of the “jumping to conclusions” bias in patients with psychiatric conditions and in a group of healthy volunteers, and to understand if there is a link between the “jumping to conclusions” bias and the personality traits “intolerance of uncertainty” and “ideological rigidity”. Method: case and control study, taking as cases those patients admitted at the Psychiatry Unit of the Complejo Hospitalario de Ourense with diagnosis of schizophrenia, depression, or bipolar disorder, and healthy volunteers as control. Tools: ball test, drawing test or BADE (Bias Against Disconfirmatory Evidence), and Obsessional Beliefs Questionnaire.Results: the final sample included 100 subjects (cases: 50 with psychiatric conditions, and controls: 50 without psychiatric conditions). In the ball task, cases needed a mean (standard deviation) of 4.66 balls (2.81) in order to make a decision, vs. 2.94 (2.80) in controls; this is a significant difference. In the BADE, psychiatric patients valued significantly as more feasible the option stated in slide 1, in comparison with healthy subjects. There is a significant correlation between the scores in the ball test and the “intolerance of uncertainty” (r= -0,285) and “ideological rigidity” (r= -0,322) traits; no significant differences were found in any of the variables based on diagnosis. Conclusions: all patients with psychiatric conditions included in the study presented the “jumping to conclusions” bias, while healthy volunteers did not have it. The presence of this bias is correlated with intolerance of uncertainty and ideological rigidity.

Bias against Disconfirmatory Evidence in a large Nonclinical Sample: Associations with Schizotypy and Delusional Beliefs

Bias against disconfirmatory evidence (BADE) is associated with delusion-like ideation and delusion-related aspects of schizotypy in nonclinical populations. Using a well-validated BADE assessment, we sought to demonstrate that only one of two facets of BADE (Evidence Integration Impairment, but not Positive Response Bias) accounts for these associations. To this end, 738 MTurk participants completed a survey which included the Schizotypal Personality Questionnaire (SPQ) and a version of the aforementioned BADE assessment. Using multiple regression, it was found that only Evidence Integration Impairment accounted for unique variance in delusion-related SPQ subscale scores. These results suggest, consistent with our hypothesis, that Evidence Integration Impairment might solely account for previously observed associations between BADE more generally and various cognitions/personality traits. It follows from this suggestion that in the general population ambiguous situations may combine with cognitive biases to maintain delusion-like ideation.