Bias Against Disconfirmatory Evidence Research Articles

Both bias against disconfirmatory evidence and political orientation partially explain the relationship between dogmatism and racial prejudice

BackgroundDogmatism and prejudice are strongly related. We hypothesized that bias against disconfirmatory evidence (BADE) might explain a portion of this relationship unique from that explained by constructs including Political Orientation. BADE (measured by the BADE task) comprises two facets, Evidence Integration Impairment and Positive Response Bias. Only Evidence Integration Impairment was expected to partially explain the prejudice-dogmatism relationship because in prior research it alone was associated with group differences in inflexible beliefs. Method254 MTurk participants completed measures of dogmatism, racial prejudice, BADE (Evidence Integration Impairment and Positive Response Bias), and Political Orientation. The hypothesized mediation effect was examined using a bootstrapping procedure. ResultsDogmatism predicted racial prejudice [b=0.24, t(249)=4.92, p<.001]; this relationship weakened in the presence of the above measures [b=0.05, t(246)=0.91, p=.363]. The 95% confidence interval for the size of the indirect effect of dogmatism on racial prejudice via Evidence Integration Impairment did not include zero [0.151, 0.331], confirming the hypothesized mediation effect. ConclusionsEvidence Integration Impairment accounts for a unique portion of the relationship between dogmatism and racial prejudice, suggesting that belief revision failures in ambiguous social situations may support prejudice in dogmatic individuals.

Bias against disconfirmatory evidence in the ‘at-risk mental state’ and during psychosis

Prior studies have confirmed a bias against disconfirmatory evidence (BADE) in schizophrenia which has been associated with delusions. However, its role in the pathogenesis of psychosis is yet unclear. The objective was to investigate BADE for the first time in subjects with an at-risk-mental-state for psychosis (ARMS), patients with a first episode of psychosis without antipsychotic treatment (FEP) and healthy controls (HC). A standard BADE test presenting written scenarios was employed. In addition, psychometric rating scales and a neuropsychological test battery were applied. A three-staged image was revealed. FEP-patients showed a significant BADE compared to the other groups. The performance of ARMS-patients lay in between HC and FEP-patients. A trend towards significance became evident for a bias against confirmatory evidence (BACE) in FEP-patients. Results were not attributable to antipsychotic or other medication or depressive symptoms. Correlations with delusions reached medium effect sizes but failed significance after Bonferroni-corrections. These results provide evidence for aberrations in evidence integration in the pathogenesis of psychosis and contribute to our knowledge of metacognitive functioning which can be used for (meta-)cognitive intervention in psychosis.

Dopamine effects on evidence gathering and integration.

Disturbances in evidence gathering and disconfirmatory evidence integration have been associated with the presence of or propensity for delusions. Previous evidence suggests that these 2 types of reasoning bias might be differentially affected by antipsychotic medication. We aimed to investigate the effects of a dopaminergic agonist (L-dopa) and a dopaminergic antagonist (haloperidol) on evidence gathering and disconfirmatory evidence integration after single-dose administration in healthy individuals. The study used a randomized, double-blind, placebo-controlled, 3-way crossover design. Participants were healthy individuals aged 18-40 years. We administered a new data-gathering task designed to increase sensitivity to change compared with traditional tasks. The Bias Against Disconfirmatory Evidence (BADE) task was used as a measure of disconfirmatory evidence integration. We included 30 individuals in our study. In the data-gathering task, dopaminergic modulation had no significant effect on the amount of evidence gathered before reaching a decision. In contrast, the ability of participants to integrate disconfirmatory evidence showed a significant linear dopaminergic modulation pattern (highest with haloperidol, intermediate with placebo, lowest with L-dopa), with the difference between haloperidol and L-dopa marginally reaching significance. Although the doses used for haloperidol and L-dopa were similar to those used in previous studies, drug plasma level measurements would have added to the validity of findings. Evidence gathering and disconfirmatory evidence integration might be differentially influenced by dopaminergic agents. Our findings are in support of a dual-disturbance account of delusions and provide a plausible neurobiological basis for the use of interventions targeted at improving reasoning biases as an adjunctive treatment in patients with psychotic disorders.

Combined neurocognitive and metacognitive rehabilitation in schizophrenia: Effects on bias against disconfirmatory evidence

BackgroundA Metacognitive Training for Schizophrenia patients (MCT) was developed to target the cognitive biases that characterize the illness. Results suggest positive MCT effects encompassing several aspects of psychopathology and subjective well-being. There are still open questions concerning the effect on different cognitive biases and the interplay between them and both psychopathology and neurocognition. Specifically, the bias against disconfirmatory evidence (BADE) has never been tested in previous trials on MCT. In this study we evaluated the feasibility of MCT combined with a cognitive remediation therapy (CACR) in schizophrenia and its effect on BADE. Moreover, we investigated the relationships between BADE and both neuropsychology and psychopathology, taking into account mutual influences on the degree of improvement. MethodsFifty-seven schizophrenia outpatients were randomly assigned to CACR + control group or MCT+CACR and assessed at baseline and after treatment for psychopathology, neurocognition and BADE. ResultsAfter MCT+CACR patients showed significantly greater improvements on BADE. Although BADE baseline performances correlated with several cognitive domains, no association was found between BADE improvement and neurocognitive nor psychopathological measures. ConclusionsThis study enlightened for the first time the efficacy of MCT+CACR on BADE in schizophrenia, suggesting the importance to develop a more specific intervention tailored on individual needs of patients.

Jumping to Conclusions bias, BADE and Feedback Sensitivity in schizophrenia and schizotypy.

Several studies about schizophrenia have shown a cognitive bias named "Jumping to Conclusions" (JTC), defined as a decision made quickly on the basis of little evidence that occurs in these patients when performing probabilistic reasoning paradigms. The main objective of this study is to compare JTC bias and BADE (Bias Against Disconfirmatory Evidence) in patients with schizophrenia vs. participants with high/low schizotypy to understand the underlying mechanism of these cognitive biases. Probabilistic reasoning was assessed using a modified version of Drawing to Decision task. In addition to the traditional parameters of this task (Plausibility Rating (PR), Draws to Decision (DTD), BADE) we also calculated new parameters, overall accuracy and one named Feedback Sensitivity (FS) which lower scores shows greater use of feedback. The results of the study suggest a context effect: in the cued condition, there were not main differences between groups. In the uncued condition, we found higher JTC bias at stage 1 for patients. At the same time, PR at first stages related positively with Feedback Sensitivity and negatively with accuracy for patients and high schizotypy participants (high confidence is associated with worse performance and lower feedback use). BADE seems unrelated to JTC bias and FS. The results are discussed in terms of JTC like as a clinical bias and whether patients with schizophrenia are less able to use feedback.

Patterns of evidence integration in schizophrenia and delusion

Previous studies documented a bias against disconfirmatory evidence (BADE) in patients affected by schizophrenia spectrum disorders, with some discrepant findings on its relationship with delusions. In order to further investigate the patterns of evidence integration in schizophrenia and delusion, we recruited 40 deluded and non-deluded patients with schizophrenia and 40 healthy control subjects. Participants were administered the BADE test, which consisted of 30 delusion-neutral scenarios, each one progressively described by three subsequent disambiguating statements and providing four types of interpretation to rate for plausibility; at every additional evidence presentation, participants were asked to adjust their ratings. In contrast to previous works, patients displayed both a BADE and a bias against confirmatory evidence (BACE) relative to healthy subjects, as they reduced plausibility ratings on incorrect interpretations and increased plausibility ratings on correct interpretation significantly less over trial progress. Moreover, BACE and BADE measures showed to discriminate differentially control from schizophrenia participants and delusional from non-delusional patients.

Schizotypal people stick longer to their first choices

Many studies have reported that schizophrenic patients show a Bias Against Disconfirmatory Evidence (BADE). This cognitive bias has been related to the formation and maintenance of delusion. The aim of this paper was to study whether BADE was present in healthy people displaying psychometric schizotypy, and to compare a closure task, which has been used for schizophrenia, with a new chronometric paradigm. Results with the new paradigm showed that the high-schizotypy group maintained their initial hypotheses longer than the low-schizotypy group. This finding corroborated the similarities between schizophrenic disorder and schizotypal traits, in this case with respect to the BADE. Research of this kind could facilitate the study of cognition in the schizophrenic spectrum without the difficulties of working with schizophrenic patients for some tasks and the assessment and early intervention in at-risk populations.

Cognitive factors associated with subclinical delusional ideation in the general population

Cognitive biases have been found to be associated with delusions in schizophrenia and schizotypy. In the current study, we examined the relationship between subclinical delusional ideation, measured using the Peters Delusions Inventory, and cognitive biases including the bias against disconfirmatory evidence (BADE), ‘jumping to conclusions’, and need for closure, evaluated using the computerized BADE program, in a sample of 117 healthy, non-psychiatric controls. Our results suggest that subclinical delusional ideation is associated with BADE, greater need for closure, a ‘jumping to conclusions’ response style, and a tendency to rate absurd and unlikely interpretations of an event as more plausible, which might be indicative of insufficient evidence integration or ‘liberal acceptance’. These cognitive biases, which occur in a much milder fashion than seen in typical deluded patient samples, may nonetheless additively play a role in the development of delusional ideation, and suggest common pathways seen in healthy and psychiatric samples.

Impaired Evidence Integration and Delusions in Schizophrenia

A bias against disconfirmatory evidence (BADE) appears to be related to delusions in schizophrenia. However, preliminary studies have either not used the most comprehensive version of the BADE task, not included a psychiatric control group, and/or have used difference score methodology instead of analyzing all available measures. In the current study a comprehensive version of the BADE task was administered to people with schizophrenia, bipolar disorder and a healthy control group. The BADE task required rating four interpretations of delusion-neutral scenarios three times (in sequence) as increasingly disambiguating information was presented. A principal component analysis (PCA) carried out on all measures determined that two independent cognitive processes appear to combine to determine all responses on the BADE task: Integration of Evidence and Conservatism, with only the former discriminating between the severely delusional schizophrenia group and all other groups. Thus, integration of evidence appears to be functioning sub-optimally in severely delusional schizophrenia patients, resulting in a bias against disconfirmatory evidence (BADE). The cognitive process theorized to be underlying this effect is hypersalience of evidence-hypothesis matches.

Incorrigibility, jumping to conclusions, and decision threshold in schizophrenia

Introduction. Previous studies confirmed a bias against disconfirmatory evidence (BADE) for both delusional and delusion-neutral events in paranoid schizophrenia. In the present study, we examined a potential relationship between the BADE and delusional ideation. Methods. Fifty-five patients with schizophrenia (32 with current delusions), 20 patients with obsessive-compulsive disorder and 30 healthy participants were presented written scenarios composed of three successive sentences which increasingly disambiguated the situation. Participants were asked to rate interpretations presented along with the sentences. After each new sentence, participants could adjust their judgements in view of the new information. One interpretation (“true”) did not seem to fit the first statement but became increasingly plausible, whereas “lure” interpretations appeared very likely initially but were eventually incorrect. Patients were given the option to decide for one of the statements. Results. Patients with schizophrenia, irrespective of delusion severity, attenuated their ratings significantly less for lure interpretations in face of disconfirmatory evidence (BADE) compared to both control groups. We found no impairment regarding the integration of confirmatory evidence. Patients with schizophrenia made more incorrect decisions after the first sentence indicating jumping to conclusions relative to healthy controls. Participants with schizophrenia showed a lowered decision threshold compared to the controls. Conclusions. The findings lend further evidence to the claim that patients with schizophrenia are hastier and rather inflexible in their decision making. This response pattern may represent a trait-like vulnerability factor for the emergence of delusional incorrigibility, a hallmark symptom of schizophrenia.

Belief inflexibility in schizophrenia

Background. Previous studies using delusion-neutral material have demonstrated that patients with schizophrenia, particularly those with delusions, display a bias against disconfirmatory evidence (BADE). In the current study we investigated the moderating impact of belief strength on this effect. Methods. Thirty-three schizophrenia patients, 18 patients with obsessive compulsive disorder, and 25 healthy control participants, were consecutively presented with delusion-neutral statements that provided increasingly detailed information about a scenario. They were asked to re-rate the plausibility of four descriptions of the scenario. The correct (“true”) interpretation appeared poor on the first statement and then increasingly gained plausibility, whereas “lure” interpretations appeared plausible initially to varying degrees, but became implausible once all information was presented. Results. Schizophrenia patients displayed a BADE for strong beliefs, in that they were biased against revising their ratings of lure items in light of new disconfirming evidence compared to the mixed control group. However, like controls, patients with schizophrenia were willing to revise weak beliefs. Conclusion. This confirms that schizophrenia patients are generally impaired in their ability to integrate disconfirmatory evidence, even for material that does not touch on delusional themes. This response pattern was more pronounced for strong beliefs, and this may contribute to the fixation of false ideas (i.e., delusions).

A Bias Against Disconfirmatory Evidence Is Associated With Delusion Proneness in a Nonclinical Sample

Previous work has suggested that a bias against disconfirmatory evidence (BADE) may be associated with the schizophrenia spectrum. The current investigation focused on whether a BADE (1) overlaps with traditional measures of memory and executive functions or selectively taps into a unique aspect of cognition and (2) is correlated with delusional ideation but not with other aspects of schizotypy. Sixty-eight undergraduate students were administered the Schizotypal Personality Questionnaire (SPQ), the BADE test, the Rey Auditory Verbal Learning Test (RAVLT), the Wisconsin Card Sorting Test (WCST), the Trail Making Tests A and B (TMT), and tests used to estimate IQ. Factor analysis of all cognition measures resulted in a 6-factor solution, 4 of which reflected the 4 domains of neuropsychological tests (WCST, RAVLT, TMT, and IQ), and 2 of which reflected different aspects of the BADE test: Initial Belief and Integration of Disconfirmatory Evidence. This solution suggests that BADE measures were independent from the other cognitive domains measured. Integration of Disconfirmatory Evidence was the only factor that correlated with delusion-content subscales of the SPQ, providing support for the contribution of a BADE to delusional ideation.

A cognitive bias against disconfirmatory evidence (BADE) is associated with schizotypy

A bias against disconfirmatory evidence (BADE) has been observed in schizophrenia, and in the present study we evaluated whether this extends to a nonclinical sample scoring high on a schizotypy scale. Thirty-seven high and 32 low schizotypy healthy participants were sequentially presented with three sentences that increasingly disambiguated the true content of a delusion-neutral scenario and were asked to rate the plausibility of four interpretations for this scenario. Relative to low schizotypy participants, high schizotypy participants continued to endorse their initial beliefs, even in the face of evidence that disconfirmed these beliefs. This result provides support for the “schizophrenia spectrum” account of psychosis.

A generalized bias against disconfirmatory evidence in schizophrenia

Fixation onto false/unrealistic beliefs is a core feature of schizophrenic delusions. A recent study conducted by our research group has provided evidence for the presence of a bias against disconfirmatory evidence (BADE) in patients with schizophrenia. Importantly, this bias was found with delusion-neutral material. To further validate a BADE as an underlying component of schizophrenic delusions, we recruited 34 presently deluded and non-deluded patients with schizophrenia, along with 26 healthy and 46 mixed psychiatric control participants. Participants were administered a closure task. On each trial, a common object (e.g., elephant) was increasingly disambiguated (i.e., shown in decreasing degrees of fragmentation). The participants were required to assess the plausibility of different interpretations at each of the up to eight stages in each trial. In line with the main hypothesis, patients with schizophrenia downgraded the ratings for incorrect interpretations significantly less over the course of task completion than did healthy and psychiatric controls. In contrast, the gradual upgrading of correct interpretations was similar across all groups, suggesting that the pattern of results obtained for incorrect interpretations reflects a BADE and not a mere repetition of prior responses or a lack of attention to the task at hand. The present study suggests that a BADE is a core feature of schizophrenia, and that this style of thinking is not confined to delusion-congruent scenarios.

The Contribution of a Cognitive Bias Against Disconfirmatory Evidence (BADE) to Delusions in Schizophrenia

A neuropsychological paradigm is introduced that provides a measure of a bias against disconfirmatory evidence (BADE), and its correspondence with delusions in people with schizophrenia and schizoaffective disorder was investigated. Fifty-two patients diagnosed with schizophrenia or schizoaffective disorder (36 were acutely delusional) and 24 healthy control participants were presented with delusion-neutral pictures in each trial, and were asked to rate the plausibility of four written interpretations of the scenario depicted by that picture. Subsequently, new pictures that provided background information about the depicted scenario were successively presented, and participants were requested to adjust their ratings, taking into account this new information. Two of the interpretations appeared tenable initially but ultimately proved to be implausible, one appeared untenable initially but eventually proved to be plausible, and one appeared untenable at all stages. A BADE was observed for delusional compared to non-delusional patients, as well as for all patients compared to controls. In addition, regardless of symptom profile, patients were more accepting of implausible interpretations than controls. The present work suggests that deficits in reasoning may contribute to the maintenance of delusions via an impairment in the processing of disconfirmatory evidence. The authors thank Jessica Bristowe, Jannine Laseleta, and Tonya Kragelj for assistance with data collection and data management, and Drs. Karin Christensen, Mahesh Menon, Elton Ngan, Eric Strachan, and Ivan Torres for comments and discussions that shaped this work. This research was supported by post-doctoral fellowships from the Mind Foundation of BC, the Canadian Psychiatric Research Foundation, and the Canadian Institutes of Health Research to TSW, scholarships from the German Academic Exchange Program (DAAD) to SM, and a grant from the Riverview Hospital Academic Steering Committee to TSW.

Reasoning styles and delusions in early psychosis

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.