Metacognitions in proneness towards hallucinations and delusions

The objectives of the present study were to examine the degree of co-existence of hallucinations and delusions in the nonclinical population. In addition, we wished to investigate the role of metacognitions in hallucinations and delusions. Finally, we explored the relative roles of positive and negative metacognitive beliefs in proneness to hallucinations and delusions. Three hundred and thirty-one nonclinical participants completed instruments assessing: hallucination-proneness (Launay-Slade Hallucinations Scale; LSHS), delusion-proneness (21-item version of the Peters et al. Delusions Inventory; PDI-21) and metacognitive beliefs (Meta-Cognitions Questionnaire; MCQ). Participants were successively grouped according to their scores on the LSHS and the PDI-21. Results revealed that hallucination-proneness was positively and significantly associated with delusion-proneness. Furthermore, hallucination-prone and delusion-prone participants scored significantly higher on some sub-scales of the MCQ compared to non-prone participants. Finally, multiple regression analysis revealed that positive and negative beliefs were good predictors of proneness towards hallucinations and delusions.     

An observation on Carnapʼs Continuum and stochastic independencies

We characterize those identities and independencies which hold for all probability functions on a unary language satisfying the Principle of Atom Exchangeability. We then show that if this is strengthen to the requirement that Johnson?s Sufficientness Principle holds, thus giving Carnap?s Continuum of inductive methods for languages with at least two predicates, then new and somewhat inexplicable identities and independencies emerge, the latter even in the case of Carnap?s Continuum for the language with just a single predicate.     

Mathematical determinacy and the transferability of aboutness

Competent speakers of natural languages can borrow reference from one another. You can arrange for your utterances of ‘Kirksville’ to refer to the same thing as my utterances of ‘Kirksville’. We can then talk about the same thing when we discuss Kirksville. In cases like this, you borrow “aboutness” from me by borrowing reference. Now suppose I wish to initiate a line of reasoning applicable to any prime number. I might signal my intention by saying, “Let p be any prime.” In this context, I will be using the term ‘p’ to reason about the primes. Although ‘p’ helps me secure the aboutness of my discourse, it may seem wrong to say that ‘p’ refers to anything. Be that as it may, this paper explores what mathematical discourse would be like if mathematicians were able to borrow freely from one another not just the reference of terms that clearly refer, but, more generally, the sort of aboutness present in a line of reasoning leading up to a universal generalization. The paper also gives reasons for believing that aboutness of this sort really is freely transferable. A key implication will be that the concept “set of natural numbers” suffers from no mathematically significant indeterminacy that can be coherently discussed.     

A comparison of autogenous/reactive obsessions and worry in a nonclinical population: a test of the continuum hypothesis

Employing the autogenous-reactive model of obsessions (Behaviour Research and Therapy 41 (2003) 11-29), this study sought to test a hypothesized continuum where reactive obsessions fall in between autogenous obsessions and worry with respect to several thought characteristics concerning content appraisal, perceived form, and thought triggers. Nonclinical undergraduate students (n=435) were administered an online packet of questionnaires designed to examine the three different types of thoughts. Main data analyses included only those displaying moderate levels of obsessions or worries (n=252). According to the most distressing thought, three different groups were formed and compared: autogenous obsession (n=34), reactive obsession (n=76), and worry (n=142). Results revealed that (a) relative to worry, autogenous obsessions were perceived as more bizarre, more unacceptable, more unrealistic, and less likely to occur; (b) autogenous obsessions were more likely to take the form of impulses, urges, or images, whereas worry was more likely to take the form of doubts, apprehensions, or thoughts; and (c) worry was more characterized by awareness and identifiability of thought triggers, with reactive obsessions through these comparisons falling in between. Moreover, reactive obsessions, relative to autogenous obsessions, were more strongly associated with both severity of worry and use of worrying as a thought control strategy. Our data suggest that the reactive subtype represents more worry-like obsessions compared to the autogenous subtype.     

Analysis of the multidimensionality of hallucination-like experiences in clinical and nonclinical Spanish samples and their relation to clinical symptoms: implications for the model of continuity

Numerous studies have found that hallucinatory experiences occur in the general population. But to date, few studies have been conducted to compare clinical and nonclinical groups across a broad array of clinical symptoms that may co-occur with hallucinations. Likewise, hallucination-like experiences are measured as a multidimensional construct, with clinical and subclinical components related to vivid daydreams, intrusive thoughts, perceptual disturbance, and clinical hallucinatory experiences. Nevertheless, these individual subcomponents have not been examined across a broad spectrum of clinically disordered and nonclinical groups. The goal of the present study was to analyze the differences and similarities in the distribution of responses to hallucination-like experience in clinical and nonclinical populations and to determine the relation of these hallucination-like experiences with various clinical symptoms. These groups included patients with schizophrenia, non-psychotic clinically disordered patients, and a group of individuals with no psychiatric diagnoses. The results revealed that hallucination-like experiences are related to various clinical symptoms across diverse groups of individuals. Regression analysis found that the Psychoticism dimension of the Symptom Check List (SCL-90-R) was the most important predictor of hallucination-like experiences. Additionally, increased auditory and visual hallucination was the only subcomponent that differentiated schizophrenic patients from other groups. This distribution of responses in the dimensions of hallucination-like experiences suggests that not all the dimensions are characteristic of people hearing voices. Vivid daydreams, intrusive thoughts, and auditory distortions and visual perceptual distortions may represent a state of general vulnerability that does not denote a specific risk for clinical hallucinations. Overall, these results support the notion that hallucination-like experiences are closer to a quasi-continuum approach and that total scores on these scales explain a state of vulnerability to general perceptual disturbance.     

The relationship between bullying, psychotic-like experiences and appraisals in 14-16-year olds

The psychological consequences of bullying have been the focus of much research over the last 25 years. However, the relationship between bullying and psychotic experiences has been relatively ignored despite the weight of evidence which suggests that traumatic events in childhood are significantly related to psychotic disorders. 373 pupils aged between 14 and 16 years took part in the study. They were asked to complete a number of self-report measures which examined their experience of bullying, predisposition to auditory hallucinations, paranoia and dissociation, and beliefs about both the self and the world and about paranoia. It was found that bullying was significantly associated with predisposition to psychotic experiences. Negative post-trauma cognitions were also associated with predisposition to psychotic phenomena as were positive beliefs about paranoia. Being bullied at school and beliefs about trauma and psychotic symptoms may contribute to the development of psychosis. However, it is also possible that these results indicate that experiencing psychotic-like phenomena increases the likelihood that a pupil's interpersonal context is characterised by peer hostility and rejection. The implications of these results are discussed.     

Content difference between normal and abnormal obsessions

Although it has long been thought that experiencing an obsession is a psychiatric symptom, more recent literature, has seen the normalisation of obsessions and other presumably clinical phenomena. That is, not only people suffering from psychiatric disorders experience obsessions but non-clinical individuals also do so. Furthermore, it has been argued that such normal obsessions are very similar to abnormal ones, in terms of content. However, in the present study, evidence was obtained indicating that normal and abnormal obsessions do differ in content. A sample of 133 healthy undergraduates was given a list of 70 obsessions, with some originating from obsessive-compulsive disorder (OCD) patients, and others stemming from healthy volunteers. Participants were asked to indicate whether they had ever experienced these obsessions. Participants endorsed significantly more normal than abnormal obsessions, suggesting that the two kinds of obsessions do differ from each other. In addition, the experience of clinical obsessions was more strongly associated with scores on a measure of OCD symptoms, than was the experience of normal obsessions.