Delusions can be reliably identified in clinical populations. However their definition has been a matter of controversy. Attributes that are commonly used to characterise delusions, such as falsity and excessive conviction, do not generally distinguish them from more ordinary beliefs. The convention that considers delusions as forms of belief obscures many of the important points of distinction from more ordinary beliefs. Conceptual review of the concept of bizarre delusions suggests that delusions are distinguishable from other forms of belief by virtue of their individual bizarreness. That is, delusions depart from what might be the understandable beliefs or experiences for a given individual. Departure from what is objectively possible or culturally sanctioned or expected are useful, but potentially misleading, proxies for individual bizarreness. Although individual bizarreness may be the key defining feature of delusional phenomena, bizarreness, however conceived, may not usefully distinguish different subtypes of delusion. The idea that delusions are best considered to be on a continuum with more ordinary beliefs is problematic. The continuum hypothesis depends on overemphasis on falsity and complete conviction as identifying characteristics of delusions. Both continuum and category approaches to delusions have utility that depends on the immediate purpose, but neither approach in itself can be presumed to show the greater verisimilitude. Overvalued ideas are another group of strongly held beliefs that may be false and idiosyncratic. Their relationship to delusions has been uncertain. It is argued that overvalued ideas and delusions are different kinds of phenomena, as overvalued ideas lack the individual bizarreness of delusions. A comparison of delusions in individuals with schizophrenia, with over-valued ideas in individuals with non-psychotic mental disorders, is reported. Several differences between delusions and over-valued ideas were identified. Over-valued ideas were associated with more gradual onset, greater preoccupation, and more concern about the opinions of others about the belief. Delusions were less plausible in their content and the deluded individuals often accounted for the origin of their delusion by referring to other psychotic experiences such as hallucinations. Conviction and insight were not found to differ across the two groups. Delusions are experiences that have many of the external characteristics of ordinary human belief. However overemphasis on these similarities results in neglect of important differences, and may lead to clinical error.

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.

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Allusions, Illusions and Delusions (2013) is an eight minute work for full orchestra that blends elements of lyricism with fast kinetic music, orchestral tutti with smaller groupings and solos, and familiar harmonic language with more exotic combinations. The piece begins with a bang, employing a figure that blurs the distinction between major and minor triads. After the ensuing short introduction, the flugelhorn’s lyrical theme becomes the main focus; indeed, elements of this solo line help to shape the entire piece. Following an expansive orchestral tutti built on this theme, the line and the ensemble are broken down and small groups of instruments begin a climb to the fast section of the piece. The longest portion of the score, this fast section takes the listener on a roller coaster ride with sharp turns and many ups and downs. The ride continues building more and more intensity and energy until the climax, marked in the score “huge and bombastic.” As this cacophonous “wall of sound” dies down, four solo strings and a clarinet emerge, recalling moments of the flugelhorn solo. A solo bucket muted trumpet presents a final paraphrase of the theme, bringing the piece to a calm and soothing resolution. Allusions, Illusions and Delusions takes its title from elements of the piece itself and from a number of external influences. The lyrical flugelhorn solo beginning at measure 27, the rapidly changing harmonies of the fast section, polychordal segments (such as the Eb major/d minor simultaneous sonority found in measures 87 through 89), and the climax at J, allude to the sounds of triadic harmonies from common practice tonal music. Aspects of these harmonies also create a sense of illusion: The main melodic and harmonic sounds used in the piece are intervals of seconds and thirds, and their inversions. By using minor seconds simultaneously as melodic and harmonic intervals, the quality of a triad or chord is often blurred, fooling the listener into thinking that they are hearing a triad, when five or more notes might actually be present. Delusion refers to the way a listener might react to the music. Often listeners invent a story to go along with a piece of music as a way for them to organize and understand the musical journey that they are experiencing. When there is no extra-musical idea tied to the piece at all, as in this instance, listeners might well be deluding themselves.

Introduction: The connection between self and psychosis has been qualitatively noted for centuries, but left relatively neglected in the field of quantitative psychology research. Some targeted studies have shown that self-concept is different in patients with psychosis than healthy volunteers. Studies of individuals have established a specific relationship between distortions of self and the content of delusions. Recent studies have begun to collect evidence of changes of self in the early stages of psychosis. Research suggests that delusions and self-concept have various shared cognitive mechanisms and neuroanatomy, particularly with respect to persecutory delusions. Changes in self-concept are apparent in persons at ultra high risk for developing psychosis, suggesting that it precedes specific symptomatology and could be at the root of delusion formation. Therefore, we identify where the two domains intersect while overcoming the limitations of past studies such as considering only persecutory delusions, minimally defining self, and including patients with a wide range of diagnoses. Methods: We consider delusions and self-concept in a patient group, consisting of 22 persons with first-episode schizophrenia spectrum disorders, and a group of 22 healthy volunteers. Delusional ideation is measured through the Peters et al Delusion Inventory (PDI) which derives a total, three subscores- Distress, Preoccupation, Conviction- and seven factor scores based on delusion content. Self-concept is quantified using hierarchical classification (HICLAS) analysis which generates numeric and visual outputs. It is important to specify that self is a deceivingly broad topic of which we will focus on the trait level- that is, which adjectives individuals use to describe their selves and others who are close to them. In addition to PDI and HICLAS evaluations, patients undergo clinical diagnoses and symptom ratings. Results: While there was no diagnostic group difference in the PDI total or subscores, patients had more delusional ideation with respect to three types of content, as determined by the factor scores. HICLAS did not show group differences. However, patients and controls had different relationships between PDI and HICLAS measures, with patients showing a greater overall connection between the two domains. The specific results are discussed, including two qualitative case studies. Conclusion: We conclude that the relationship between self-concept and schizophrenia is specific to delusions rather than general symptomatology. Relationships are drawn between the cognitive theories underlying each domain. The findings are important to theoretical understandings of self and delusions. Furthermore, it is hoped that advanced understanding of these topics can likely lead to new, targeted psychotherapeutic treatment approaches. / published_or_final_version / Psychiatry / Master / Master of Philosophy

published_or_final_version / Psychiatry / Master / Master of Philosophy

The practice of inquiry, in which we seek and pursue true beliefs by forming justified beliefs, is important to us. This thesis will address two questions concerning the significance of this practice. These are the question of what explains our preference for this particular belief-forming practice, and whether this value can be explained by the value of true belief alone. To answer these questions I will examme a variety of our intuitive commitments to particular values, assuming their general accuracy. I will use an inference from the goal of a practice to the value of a practice, an inference based on the assumption that when we pursue something it is valuable. I will discuss our intuitive commitments to the value of justification. I will also rely on the implications of the presence of pride and admiration in relation to the outcome of an inquiry (especially in situations where a belief is difficult to form). By using this methodology, I will argue for three sources of value that explain the unique significance of the value of inquiry. The first is the value of its unique role in our being able to form reliably true beliefs. Second, I will argue for Wayne D. Riggs' account of epistemic credit; Riggs defends the value of our being responsible for true beliefs, they are our achievements. Third, I will argue for an additional the value of delivering a skilful epistemic performance, another kind of achievement. I will show that although the value of true belief plays a role in explaining some of the values, the third value for inquiry is independent of the value of true belief. This means that there are intellectual rewards, which can be gained from this practice, that extend beyond the value of true belief. / KMBT_363 / Adobe Acrobat 9.54 Paper Capture Plug-in

Previous research has suggested that there are multiple psychological processes underlying delusional thought. While it appears that cognitive biases in certain reasoning and attention processes are related to delusion-proneness, the influence of emotion on these processes is not well understood. The overall objective of this study was to investigate the effect of emotional content on performance on tasks thought to measure attentional bias, preferential recall, and probabilistic reasoning in individuals with schizophrenia and demographically matched controls. In order to account for level of delusion-proneness, participants also completed a multidimensional measure of delusional thought. It was hypothesized that individuals with schizophrenia would perform more poorly on both the emotional and neutral versions of these tasks compared to controls. It was also hypothesized that within each group, there would be a statistically significant emotion effect, indicated by a difference in performance on the emotional (compared to neutral) condition of each task. This emotion effect was expected to be larger in the schizophrenia group. Finally, it was hypothesized that the emotion effect would increase as the severity of delusional proneness increased for all participants, regardless of group. As hypothesized, the schizophrenia group performed more poorly on the tasks overall, though expected emotion effects were generally absent. There were no differences in the size of emotion effects between the groups on any of the cognitive tasks administered, and the emotion effect did not appear to increase as severity of delusion-proneness increased. Factors that may have contributed to this pattern of results are discussed. Implications of these findings on theoretical models of delusions and future directions for research in this area are also discussed.