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

Neurocognitive performance and cognitive biases in young adults with schizotypal traits

Recent research suggests that neurocognitive deficits in patients with schizophrenia may increase the risk of developing cognitive biases. As such, we set out to determine this predictive relationship as it pertains to the development of a first-episode psychosis. We hypothesized that poorer performance in processing speed would be associated with jumping to conclusions and an externalizing bias. Poorer performance in working memory would be associated with belief inflexibility and jumping to conclusions, and poorer performance in attention would be associated with attention to threat. We hypothesized that all cognitive biases would be associated with subsyndromal positive symptoms, and schizotypal traits would moderate these relationships. Undergraduate students (N = 130) completed the Schizotypal Personality Questionnaire, DAVOS Assessment of Cognitive Biases, Community Assessment of Psychic Experiences, and a computerized neuropsychological assessment battery. Processing speed had a small effect on externalizing bias, which in turn affected subsyndromal positive symptoms. There was no moderating effect of schizotypal traits on externalizing bias, but it was significantly associated with subsyndromal positive symptoms. Only the externalizing bias was associated with subsyndromal positive symptomatology, which might be explained by a restricted range and reduced variance in performance as a result of using a university student sample. This is one of few studies that sought to explain the mechanism responsible for the development of subsyndromal positive symptoms in a healthy sample using self-report measures.

A systematic review of performance-based assessment studies on cognitive biases in schizophrenia spectrum psychoses and clinical high-risk states: A summary of 40 years of research

Cognitive models of psychosis have stimulated empirical studies on cognitive biases involved in schizophrenia spectrum psychoses and their symptoms. This systematic review aimed to summarize the studies on the role of cognitive biases as assessed in different performance-based tasks in schizophrenia spectrum psychoses and clinical high-risk states. We focused on five cognitive biases linked to psychosis, i.e., aberrant salience, attentional biases, source monitoring biases, jumping to conclusions, and bias against disconfirmatory evidence. We identified N = 324 studies published in N = 308 articles fulfilling inclusion criteria. Most studies have been cross-sectional and confirmed that the schizophrenia spectrum psychoses are related to exaggerated cognitive biases compared to healthy controls. On the contrary, less evidence suggests a higher tendency for cognitive biases in the UHR sample. The only exceptions were source monitoring and jumping to conclusions, which were confirmed to be exaggerated in both clinical groups. Hallucinations and delusions were the most frequent symptoms studied in the context of cognitive biases. Based on the findings, we presented a hypothetical model on the role of interactions between cognitive biases or additive effects of biases in shaping the risk of psychosis. Future research is warranted for further development of cognitive models for psychosis.

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.

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.

Associations between acceptance of the implausible bias, theory of mind and delusions in first-episode psychosis patients; A longitudinal study

Multiple different cognitive biases, among them the liberal acceptance (LA) bias, have been suggested to contribute to reality distortion in psychotic disorders. Earlier studies have been cross-sectional and considered a limited set of cognitive correlates of psychosis, thus the relationship between LA bias and psychosis remains poorly known. We studied a similar bias (acceptance of the implausible (AOI)) in 62 first-episode psychosis (FEP) patients and 62 control subjects, who watched movie scenes with varying degrees of realism and were asked to evaluate the probability of these events occurring in real life. We assessed theory of mind (ToM) performance using the Hinting task and delusion severity using Brief Psychiatric Rating Scale item 11. We correlated the magnitude of AOI with the severity of delusions and performance in the ToM task. Furthermore, we used 1-year follow-up data from 40 FEP patients and 40 control subjects to disentangle state vs trait-like characteristics of AOI. At baseline FEP patients expressed more AOI than control subjects, and the magnitude of AOI correlated positively with the severity of delusions and negatively with ToM performance. At the one-year follow-up, when most patients were in remission, patients still displayed increased AOI, which no longer correlated with delusions. These findings support the notion that the AOI bias could represent a trait rather than a state feature and support further studies to test the hypothesis that it could be one of the causal factors of psychotic disorders, possibly associated with ToM.

A Computational Analysis of Abnormal Belief Updating Processes and Their Association With Psychotic Experiences and Childhood Trauma in a UK Birth Cohort

BACKGROUND

Psychotic experiences emerge from abnormalities in perception and belief formation and occur more commonly in those experiencing childhood trauma. However, which precise aspects of belief formation are atypical in psychosis is not well understood. We used a computational modeling approach to characterize belief updating in young adults in the general population, examine their relationship with psychotic outcomes and trauma, and determine the extent to which they mediate the trauma-psychosis relationship.

METHODS

We used data from 3360 individuals from the Avon Longitudinal Study of Parents and Children birth cohort who completed assessments for psychotic outcomes, depression, anxiety, and two belief updating tasks at age 24 and had data available on traumatic events assessed from birth to late adolescence. Unadjusted and adjusted regression and counterfactual mediation methods were used for the analyses.

RESULTS

Basic behavioral measures of belief updating (draws-to-decision and disconfirmatory updating) were not associated with psychotic experiences. However, computational modeling revealed an association between increased decision noise with both psychotic experiences and trauma exposure, although <3% of the trauma-psychotic experience association was mediated by decision noise. Belief updating measures were also associated with intelligence and sociodemographic characteristics, confounding most of the associations with psychotic experiences. There was little evidence that belief updating parameters were differentially associated with delusions compared with hallucinations or that they were differentially associated with psychotic outcomes compared with depression or anxiety.

CONCLUSIONS

These findings challenge the hypothesis that atypical belief updating mechanisms (as indexed by the computational models and behavioral measures we used) underlie the development of psychotic phenomena.

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.

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.

Autistic traits as a potential confounding factor in the relationship between schizotypy and conspiracy beliefs

BACKGROUND

Conspiracy Theories (CT) are complex belief systems that view the world as being manipulated by multiple actors collaborating in the pursuit of malevolent goals. Although culture, education and sociological factors have been implicated in their development, psychological factors are recognized as important. Certain individual differences, including schizotypy and cognitive processing style, have been shown to make some individuals susceptible to CTs. However, the finding that schizotypy often co-occurs with autism spectrum disorder raises a question as to the relative and potentially confounding role of autistic traits in increasing vulnerability to CT beliefs.

METHOD

A total of 508 adults were recruited from an international online panel. The study included measures of conspiracy beliefs, schizotypy and autistic traits as well as measures of information searching and cognitive style.

RESULTS

The results confirmed that both autistic and schizotypy traits were positively associated with CT beliefs, but that schizotypy traits were the strongest predictor. Exploratory analyses of cognitive style measures indicated potential avenues for further investigation in relation in differences in cognitive processes that might underlie the development of CTs for in people with autistic traits as opposed to schizotypal traits.

LIMITATIONS

The study was based on a self-report methodology and did not utilise a clinical sample.

CONCLUSION

Both schizotypal and autistic traits are reliable predictors of conspiracy beliefs, but schizotypy appears to be the stronger predictor and that autistic traits are not a strong confounding factor in this relationship. However, autistic traits may pose an additional risk factor for CT beliefs.

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.

Childhood trauma and cognitive biases associated with psychosis: A systematic review and meta-analysis

Childhood trauma is associated with an increased risk of psychosis, but the mechanisms that mediate this relationship are unknown. Exposure to trauma has been hypothesised to lead to cognitive biases that might have causal effects on psychotic symptoms. The literature on whether childhood trauma is associated with psychosis-related cognitive biases has not been comprehensively reviewed. A systematic review and meta-analysis or narrative synthesis of studies examining the association between childhood trauma and the following biases: external locus of control (LOC), external attribution, probabilistic reasoning, source monitoring, top-down processing, and bias against disconfirmatory evidence. Studies were assessed for quality, and sources of heterogeneity were explored. We included 25 studies from 3,465 studies identified. Individuals exposed to childhood trauma reported a more external LOC (14 studies: SMD Median = 0.40, Interquartile range 0.07 to 0.52), consistent with a narrative synthesis of 11 other studies of LOC. There was substantial heterogeneity in the meta-analysis (I2 = 93%) not explained by study characteristics examined. Narrative syntheses for other biases showed weaker, or no evidence of association with trauma. The quality of included studies was generally low. Our review provides some evidence of an association between childhood trauma and a more external LOC, but not with the other biases examined. The low quality and paucity of studies for most of the cognitive biases examined highlights the need for more rigorous studies to determine which biases occur after trauma, and whether they mediate an effect of childhood trauma on psychosis.

Dual-process theory, conflict processing, and delusional belief

Many reasoning biases that may contribute to delusion formation and/or maintenance are common in healthy individuals. Research indicating that reasoning in the general population proceeds via analytic processes (which depend upon working memory and support hypothetical thought) and intuitive processes (which are autonomous and independent of working memory) may therefore help uncover the source of these biases. Consistent with this possibility, recent studies imply that impaired conflict processing might reduce engagement in analytic reasoning, thereby producing reasoning biases and promoting delusions in individuals with schizophrenia. Progress toward understanding this potential pathway to delusions is currently impeded by ambiguity about whether any of these deficits or biases is necessary or sufficient for the formation and maintenance of delusions. Resolving this ambiguity requires consideration of whether particular cognitive deficits or biases in this putative pathway have causal primacy over other processes that may also participate in the causation of delusions. Accordingly, the present manuscript critically evaluates whether impaired conflict processing is the primary initiating deficit in the generation of reasoning biases that may promote the development and/or maintenance of delusions. Suggestions for future research that may elucidate mechanistic pathways by which reasoning deficits might engender and maintain delusions are subsequently offered.

Data gathering ability contributes to visual organization and probabilistic reasoning

Individuals use data gathering methods to inform judgments and behaviors. Effective interaction with the environment depends on these having high accuracy and low noise, but when they become abnormal, aberrant thoughts and perceptions can occur. In this study, we examined if data gathering methods were consistent across tasks that relied on different cognitive abilities, specifically visual perception and probabilistic reasoning. Thirty-four non-clinical participants engaged in the Ebbinghaus Illusion and the Jumping to Conclusions tasks, while also completing questionnaires concerning aspects of delusion formation. A significant, positive correlation was observed between performance on the Ebbinghaus Illusion and the Jumping to Conclusions tasks. Both tasks were negatively correlated with the General Conspiracy Belief Scale. The results suggest an underlying mechanism for data gathering that is consistent across behavioral domains and exists on a continuum in the general population.

Differential relationship of jumping-to-conclusions and incorrigibility with delusion severity

Reasoning biases such as jumping-to-conclusions (JTC) and incorrigibility have been suggested to contribute to the generation and maintenance of delusions. However, it is still debated whether these biases represent stable traits of patients with delusions, or are related to state fluctuations of delusion severity. The present study aimed to elucidate this question by combining a cross-sectional with a longitudinal approach. JTC, incorrigibility and delusion severity were assessed in 79 patients with a history of delusions over a 6-month period. To allow for a differentiated look into effects of time vs. symptom changes, patients were divided into patients with (D+) and without (D-) current delusions at baseline. Significant improvement of delusions was noted in D+ at follow-up. JTC did not differ between the two patient groups either at baseline or over time. In contrast, incorrigibility was significantly higher in D+ than D- at baseline; this difference remained stable throughout the 6-month follow-up period. The two biases did not significantly co-vary over time. Our results suggest a dissociation between incorrigibility and JTC as regards their relation to current presence of delusions, and tentatively support theoretical accounts attributing different roles to the two biases in the generation (JTC) and maintenance (incorrigibility) of delusions.

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.

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.

Holding on to false beliefs: The bias against disconfirmatory evidence over the course of psychosis

BACKGROUND AND OBJECTIVES

The ability to integrate evidence into a reasoning process is crucial in order to react to changing information, e.g. to adapt one's beliefs according to new evidence or to generate new beliefs when facing better alternatives. Evidence integration ability is thus associated with belief flexibility. A specific bias of evidence integration, a bias against disconfirmatory evidence (BADE), can be found in patients with schizophrenia and has been linked to delusion development and maintenance. Knowledge about whether the BADE occurs already in risk constellations of psychosis can clarify its role in the pathogenesis of psychosis.

METHODS

This article reviews the current literature on BADE. Many studies demonstrate BADE over the course of illness, ranging from healthy controls with subclinical properties of schizotypy, over patients with at-risk mental states (ARMS) and patients with a first episode of psychosis to patients with chronic schizophrenia. These data allow a comparison of competences and deficits over the course of illness. Underlying mechanisms of BADE are discussed, including interrelations with neurocognitive performance and dopaminergic processes.

RESULTS

The BADE could be found in different phases of psychosis development and can be regarded as a cognitive marker of the beginning psychotic state.

LIMITATIONS

The presented findings are derived from independent cross-sectional studies. So far, no comprehensive longitudinal assessment has been published.

CONCLUSIONS

Treatments of metacognitive deficits in general and as early as in the ARMS might interfere with the cognitive pathogenesis of psychosis, and thereby ameliorate, postpone or even prevent the transition to psychosis.

The Importance of Metamemory Functioning to the Pathogenesis of Psychosis

Many studies up to date have implied that biases in the metacognition of memory, so called metamemory, contribute to the development and maintenance of positive symptoms in schizophrenia. However, no study exists which has longitudinally followed patients experiencing positive symptoms. The present article therefore reviews cross-sectional studies on retrospective metamemory abilities in participants within different stages of a schizophrenia spectrum disorder, with heterogeneous symptom severities, creating a pseudo-longitudinal overview. Summarized, a deterioration of these abilities correlating with psychosis development can be inferred. The reviewed publications indicate that metamemory biases can already be found in patients with an at-risk mental state for psychosis (ARMS). Patients in their first episode of psychosis (FEP) seem to be more severely impaired than ARMS-patients but similarly affected compared to chronic patients. The contribution of these biases to the pathogenesis of psychosis is discussed, giving consideration to relations with other cognitive- and metacognitive functions, neurochemical processes and neural correlates. It is hypothesized that the biases represent early cognitive markers of the beginning and persisting psychotic state. An early treatment program could help patients to ameliorate the general course of illness or even to prevent the risk of a transition to psychosis.