Academic literature on the topic 'Delusion-prone'

Background.That delusional and delusion-prone individuals ‘jump to conclusions’ is one of the most robust and important findings in the literature on delusions. However, although the notion of ‘jumping to conclusions’ (JTC) implies gathering insufficient evidence and reaching premature decisions, previous studies have not investigated whether the evidence gathering of delusion-prone individuals is, in fact, suboptimal. The standard JTC effect is a relative effect but using relative comparisons to substantiate absolute claims is problematic. In this study we investigated whether delusion-prone participants jump to conclusions in both a relative and an absolute sense.Method.Healthy participants (n = 112) completed an incentivized probabilistic reasoning task in which correct decisions were rewarded and additional information could be requested for a small price. This combination of rewards and costs generated optimal decision points. Participants also completed measures of delusion proneness, intelligence and risk aversion.Results.Replicating the standard relative finding, we found that delusion proneness significantly predicted task decisions, such that the more delusion prone the participants were, the earlier they decided. This finding was robust when accounting for the effects of risk aversion and intelligence. Importantly, high-delusion-prone participants also decided in advance of an objective rational optimum, gathering fewer data than would have maximized their expected payoff. Surprisingly, we found that even low-delusion-prone participants jumped to conclusions in this absolute sense.Conclusions.Our findings support and clarify the claim that delusion formation is associated with a tendency to ‘jump to conclusions’. In short, most people jump to conclusions, but more delusion-prone individuals ‘jump further’.

IntroductionExecutive dysfunctions in psychotic disorders, mainly schizophrenia are well-known phenomenon, however the information about executive functioning in subclinical psychotic states are still scarce. The rationale for focusing on the delusion-proneness (delusion-like states) is suggested role of executive dysfunction in the process of developing delusions.AimsOur aim is to assess the relationship between delusion-proneness and executive functions.ObjectivesWe would like to assess two cognitive functions: shifting and inhibition and updating, depending on the severity of delusion-like symptoms. We expect that higher delusion-proneness is associated with more pronounced executive dysfunctions, as it is observed in clinical population with existing delusions.MethodsIn order to assess delusion-proneness, we used Polish version of Peters et al. Delusions Inventory (PDI). To evaluate shifting and inhibition, two test were conducted–Berg's Card Sorting Task (BCST) and Stroop task respectively. Correlation analysis were performed.ResultsSixty-four participants (41 women and 23 men) were recruited in this study. Mean age was 28.8, SD = 10.37. Statistical analysis revealed significant negative correlation of PDI distress subscale and BCST non-perseverative errors. The overall score, as well as all PDI subscales correlated negatively also with the Stroop task's total number of errors and positively with the accuracy in incongruent variant.ConclusionsContrary to our expectation, results have shown that delusion-proneness is associated with better results in executive functions test, especially in terms of accuracy. These results suggest that executive functions may play a role in the development and maintenance of delusional ideation, however, its relationship may be a bit more complex.Disclosure of interestThe authors have not supplied their declaration of competing interest.

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.

That delusional and delusion-prone individuals gather less evidence before reaching a decision (“jumping to conclusions”) is arguably the most influential finding in the literature on cognitive theories of delusions. However, the cognitive basis of this data-gathering tendency remains unclear. Suggested theories include that delusion-prone individuals gather less data because they (a) misjudge the information value of evidence, (b) find data gathering more taxing than do controls, or (c) make noisier decisions than controls. In the present study we developed a novel, incentivized, nonserial data-gathering task to tease apart these alternatives. Higher delusion-proneness was associated with gathering less information on this task, even when accounting for gender, risk aversion, and intelligence. Our findings suggest that misjudging the information value of evidence contributes substantially to the “jumping to conclusions” bias and that neither higher subjective costs nor noisy decision making can fully account for it.

This thesis examines attentional and cognitive biases for particular facial expressions in delusion-prone and deluded individuals. The exploration of cognitive biases in delusion-prone individuals provides one means of elucidating psychological processes that might be involved in the genesis of delusions. Chapter 1 provides a brief review of the continuum approach to schizophrenia, and outlines recent theoretical conceptualisations of delusions. The study of schizophrenia phenomena at the symptom level has become a popular method of inquiry, given the heterogeneous phenotypic expression of schizophrenia, and the uncertainty surrounding the existence of a core neuropathology. Delusions are one of the most commonly experienced symptoms of schizophrenia, and have traditionally been regarded as fixed, false beliefs that are pathognomonic of an organic disease process. However, recent phenomenological evidence of delusional ideation in the general population has led to the conceptualisation of delusions as multi-dimensional entities, lying at the extreme end of a continuum from normal through to maladaptive beliefs. Recent investigations of the information processing abnormalities in deluded individuals are reviewed in Chapter 2. This strand of research has revealed evidence of various biases in social cognition, particularly in relation to threat-related material, in deluded individuals. These biases are evident in probabilistic reasoning, attribution style, and attention, but there has been relatively little investigation of cognitive aberrations in delusion-prone individuals. In the present thesis, social-cognitive biases were examined in relation to a standard series of faces that included threat-related (anger, fear) and non-threatening (happy, sad) expressions, in both delusion-prone and clinically deluded individuals. Chapters 3 and 4 present the results of behavioural (RT, affect recognition accuracy) and visual scanpath investigations in healthy participants assessed for level of delusion- proneness. The results indicate that delusion-prone individuals are slower at processing angry faces, and show a general (rather than emotion-specific) impairment in facial affect recognition, compared to non-prone healthy controls. Visual scanpath studies show that healthy individuals tend to direct more foveal fixations to the feature areas (eyes, nose, mouth) of threat-related facial expressions (anger, fear). By contrast, delusion-prone individuals exhibit reduced foveal attention to threat-related faces, combined with �extended� scanpaths, that may be interpreted as an attentional pattern of �vigilance-avoidance� for social threat. Chapters 5 and 6 extend the work presented in Chapters 3 and 4, by investigating the presence of similar behavioural and attentional biases in deluded schizophrenia, compared to healthy control and non-deluded schizophrenia groups. Deluded schizophrenia subjects exhibited a similar delay in processing angry faces, compared to non-prone control participants, while both deluded and non-deluded schizophrenia groups displayed a generalised affect recognition deficit. Visual scanpath investigations revealed a similar style of avoiding a broader range of negative (anger, fear, sad) faces in deluded schizophrenia, as well as a common pattern of fewer fixations with shorter duration, and reduced attention to facial features of all faces in both deluded and non-deluded schizophrenia. The examination of inferential biases for emotions displayed in facial expressions is presented in Chapter 7 in a study of causal attributional style. The results of this study provide some support for a �self-serving� bias in deluded schizophrenia, as well as evidence for an inability to appreciate situational cues when making causal judgements in both delusion-prone and deluded schizophrenia. A theoretical integration of the current findings is presented in Chapter 8, with regard to the implications for cognitive theories of delusions, and neurobiological models of schizophrenia phenomena, more generally. Visual attention biases for threat-related facial expressions in delusion-prone and deluded schizophrenia are consistent with proposals of neural dysconnectivity between frontal-limbic networks, while attributional biases and impaired facial expression perception may reflect dysfunction in a broader �social brain� network encompassing these and medial temporal lobe regions. Strong evidence for attentional biases and affect recognition deficits in delusion-prone individuals implicates their role in the development of delusional beliefs, but the weaker evidence for attributional biases in delusion-prone individuals suggests that inferential biases about others� emotions may be relevant only to the maintenance of delusional beliefs (or that attributional biases for others� emotional states may reflect other, trait-linked difficulties related to mentalising ability). In summary, the work presented in this thesis demonstrates the utility of adopting a single-symptom approach to schizophrenia within the continuum framework, and attests to the importance of further investigations of aberrant social cognition in relation to the development of delusions.

Thesis (Ph. D.)--University of Sydney, 2002.
Includes published papers co-authored by Green. Title from title screen (viewed Apr. 23, 2008). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Dept. of Psychology, Faculty of Science. Degree awarded 2002; thesis submitted 2001. Includes bibliography. Also available in print form.

Thesis (Ph. D.)--New School for Social Research, 2003.
Typescript. Includes bibliographical references (leaves 102-108). Also available in electronic format on the World Wide Web. Access restricted to users affiliated with the licensed institutions.