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

Robotically-induced auditory-verbal hallucinations: combining self-monitoring and strong perceptual priors

BACKGROUND

Inducing hallucinations under controlled experimental conditions in non-hallucinating individuals represents a novel research avenue oriented toward understanding complex hallucinatory phenomena, avoiding confounds observed in patients. Auditory-verbal hallucinations (AVH) are one of the most common and distressing psychotic symptoms, whose etiology remains largely unknown. Two prominent accounts portray AVH either as a deficit in auditory-verbal self-monitoring, or as a result of overly strong perceptual priors.

METHODS

In order to test both theoretical models and evaluate their potential integration, we developed a robotic procedure able to induce self-monitoring perturbations (consisting of sensorimotor conflicts between poking movements and corresponding tactile feedback) and a perceptual prior associated with otherness sensations (i.e. feeling the presence of a non-existing another person).

RESULTS

Here, in two independent studies, we show that this robotic procedure led to AVH-like phenomena in healthy individuals, quantified as an increase in false alarm rate in a voice detection task. Robotically-induced AVH-like sensations were further associated with delusional ideation and to both AVH accounts. Specifically, a condition with stronger sensorimotor conflicts induced more AVH-like sensations (self-monitoring), while, in the otherness-related experimental condition, there were more AVH-like sensations when participants were detecting other-voice stimuli, compared to detecting self-voice stimuli (strong-priors).

CONCLUSIONS

By demonstrating an experimental procedure able to induce AVH-like sensations in non-hallucinating individuals, we shed new light on AVH phenomenology, thereby integrating self-monitoring and strong-priors accounts.

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.

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.

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.

Jumping to Conclusions and Its Associations With Psychotic Experiences in Preadolescent Children at Familial High Risk of Schizophrenia or Bipolar Disorder-The Danish High Risk and Resilience Study, VIA 11

BACKGROUND

The jumping to conclusions (JTC) bias, ie, making decisions based on inadequate evidence, is associated with psychosis in adults and is believed to underlie the formation of delusions. Knowledge on the early manifestations of JTC and its associations with psychotic experiences (PE) in children and adolescents is lacking.

DESIGN

Preadolescent children (mean age 11.9 y, SD 0.2) at familial high risk of schizophrenia (FHR-SZ, n = 169) or bipolar disorder (FHR-BP, n = 101), and controls (n = 173) were assessed with the Beads Task to examine JTC. The number of beads drawn before making a decision, "draws to decision" (DTD) was used as a primary outcome. PE were ascertained in face-to-face interviews. General intelligence was measured with Reynolds Intellectual Screening Test.

RESULTS

Children at FHR-SZ took fewer DTD than controls (4.9 vs 5.9, Cohen's d = 0.31, P = .004). Differences were attenuated when adjusting for IQ (Cohen's d = 0.24, P = .02). Higher IQ was associated with a higher number of DTD (B = 0.073, P < .001). Current subclinical delusions compared with no PE were associated with fewer DTD in children at FHR-SZ (P = .04) and controls (P < .05). Associations between delusions and DTD were nullified when accounting for IQ.

CONCLUSIONS

JTC marks familial risk of psychosis in preadolescence, not reducible to general intelligence. JTC is associated with subclinical delusions, but this may be an expression of intellectual impairment. Future studies should establish temporality between JTC and delusion formation and examine JTC as a target for early intervention.

Rethinking delusions: A selective review of delusion research through a computational lens

Delusions are rigid beliefs held with high certainty despite contradictory evidence. Notwithstanding decades of research, we still have a limited understanding of the computational and neurobiological alterations giving rise to delusions. In this review, we highlight a selection of recent work in computational psychiatry aimed at developing quantitative models of inference and its alterations, with the goal of providing an explanatory account for the form of delusional beliefs in psychosis. First, we assess and evaluate the experimental paradigms most often used to study inferential alterations in delusions. Based on our review of the literature and theoretical considerations, we contend that classic draws-to-decision paradigms are not well-suited to isolate inferential processes, further arguing that the commonly cited 'jumping-to-conclusion' bias may reflect neither delusion-specific nor inferential alterations. Second, we discuss several enhancements to standard paradigms that show promise in more effectively isolating inferential processes and delusion-related alterations therein. We further draw on our recent work to build an argument for a specific failure mode for delusions consisting of prior overweighting in high-level causal inferences about partially observable hidden states. Finally, we assess plausible neurobiological implementations for this candidate failure mode of delusional beliefs and outline promising future directions in this area.

Hasty decision-making in individuals at higher risk of developing an eating disorder

BACKGROUND AND OBJECTIVES

The Jumping to Conclusions (JTC) bias is the tendency to make hasty decisions based on limited evidence and may contribute to the formation of over-valued beliefs about the importance of weight, shape and eating. Previous research investigating the JTC bias in clinical eating disorder samples, as assessed by the beads task, is inconclusive. The current study investigated the JTC bias in a non-clinical sample of undergraduate students identified as being lower or higher risk of developing an eating disorder. The study used a more reliable 'distractor' beads task that also incentivised hastier decisions by elevating the pressure of the task.

METHODS

Female undergraduate students (N = 156, 48%, classified as higher risk) completed a pressure and non-pressure distractor beads task, along with measures of weight concern and body-image flexibility.

RESULTS

Higher risk participants displayed a hastier decision-making style than lower risk participants. Task pressure elicited a hastier decision-making style across the whole sample, however, was unable to distinguish between higher and lower eating disorder risk status.

LIMITATIONS

Interpretation of findings are limited to non-clinical samples and may not generalise to clinical eating disorder populations.

CONCLUSIONS

Findings suggest the need for replication in a clinical eating disorder sample using the distractor beads task. Future research should investigate whether eating disorder salient stimuli elicits a stronger bias.

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.