Matthew Broome

The extended Church-Turing thesis posits that any computable function can be calculated efficiently by a probabilistic Turing machine. If this thesis held true, the global effort to build quantum computers might ultimately be unnecessary. The thesis would however be strongly contradicted by a physical device that efficiently performs a task believed to be intractable for classical computers. BosonSampling - the sampling from a distribution of n photons undergoing some linear-optical process - is a recently developed, and experimentally accessible example of such a task [1].

The papers included in the thesis, and summarized in this covering document, were selected, in discussion with my supervisor, Dr. Roessler, from papers I have published in the philosophy of psychiatry. In parallel to this philosophical work, I have worked clinically as a psychiatrist and academically as a research psychiatrist. My clinical work has largely been working with Early Intervention Services, both in South London and in Coventry and Warwickshire, and this work has been acting as a psychiatrist in clinical teams who work with young people who may either be at risk of developing a psychotic illness, or are in the earliest stages of such an illness. My empirical work has been in the same clinical group and has used functional neuroimaging and cognitive neuropsychology to characterize those at risk of psychosis and to chart the onset of psychosis and the formation of delusions. As required by the university guidelines, a full list of publications, both empirical and philosophical, is detailed in appendix 1. The papers included in the thesis hence parallel many of these clinical and empirical interests: papers 2 and 4, in particular, examine the role neuroimaging may play in studying delusions and relate the prodromal phase of psychosis to both the neurodevelopmental and continuum models of psychosis. Paper 3 is one of two papers written with Lisa Bortolotti drawing on Richard Moran’s work and examining delusions. Paper 1 is perhaps the paper least connected to my empirical and clinical work as has a wider focus and tries to examine what mental illnesses are and to begin to describe a position Lisa Bortolotti and I later expanded on and referred to as ‘psychological realism’, with Paper 2 being a case example of this account being applied to a particular area of psychopathology, namely delusions. The papers form a progression with Paper 1 outlining a general conception of mental disorder, Paper 2 being a case study of this approach specifically in the area of delusion. Paper 3 takes the example of thought insertion and develops ideas from Paper 2 that reason giving is a crucial feature that helps highlight what is pathological about certain experiences. Paper 4 brings together the philosophical concerns regarding a wholly neuroscientific conception of psychopathology, and how this is of clinical and scientific relevance when we use psychopathology to demarcate the various stages of psychotic experience and illness.

Patients with psychotic disorders experience a range of reality distortions. These often include auditory-verbal hallucinations, and thought insertion to a lesser degree; however, their mechanisms and relationships between each other remain largely elusive. Here we attempt to establish a integrative model drawing from the phenomenology of both AVHs and TI and argue that they in fact can be seen as ‘spectra’ of experiences with varying degrees of agency and ownership, with ‘silent and internal own thoughts’ on one extreme and ‘fully external and clearly audible voices’ in the absence of a speaker on the other. We believe a spectral model will add emphasis to the continuity of experience and help to better understand how one type of psychotic symptom may interact with another, and put forward the argument that the experience of TI itself is not sufficient to classify as a delusion. In addition we aim to discuss some of the conceptual issues surrounding AVHs and TI with first-person accounts and current philosophical and neuropsychological theories in mind. We propose that the mechanisms behind AVHs and TI are more complex than source-monitoring deficits; indeed, to understand such phenomena one must appreciate that their very ‘existence’ and ‘reality’ as experienced by the individual have much deeper implications and meaning, both philosophically and clinically.

In lieu of an abstract, here is a brief excerpt of the content:The Ubiquity of MoodsMatthew R. Broome (bio) and Havi Carel (bio)Keywordsphenomenology, Heidegger, moods, affects, meaning, self, philosophyPhilosophy is often caricatured as one of the most disconnected and anemic academic enterprises. Yet in philosophers’ own accounts of what drew them to the problems they have sought to address they answer, typically, in two broad, passionate, ways: wonder or anxiety. As such, philosophy, and philosophers’ self-understanding of themselves and their enterprise, can serve as a way to address some of the important topics raised by Rosfort and Stanghellini. Even for philosophers, the emotional experience of moods and affects is employed in narrativity, or at least, employed when one is called to give an account of oneself. One could envisage a party conversation along these lines:So why did you become a philosopher?Well, I wanted to go to university but wasn’t interested in science or in the humanities and I’ve always been dreadful at languages.(Laugh) But you must like something about it as you wouldn’t have become a professor?You know how it is... you drift into things. I did well as an undergraduate, my tutor suggested I should do a PhD. Found an excellent supervisor, and got a few papers published and then a teaching post....You must be very committed to the subject.Ummm—I guess so. I thought about joining the civil service after my PhD, but always managed to find work and the hours are much more flexible at universities!Well I think it is amazing: to think and teach about such important things.Do you?There is something slightly baffling here that may simply be part of the inherent irony and self-deprecation of some academics. The philosopher's interlocutor is asking about what philosophy means to the philosopher: why he has given his life to it. As such, she is alluding to a deeper, philosophical question that, after decades of falling out of favor, is returning to the attention of philosophers: namely, how has philosophy given your life meaning? The philosopher responds with possible irony, banality, or superficiality and invokes luck rather than meaning in his narrative. He serves as Nietzsche's feared nihilist. The account offered also seems to fail to meet normative standards, and depending on how the philosopher carries it off, this gap between expectation and reality in the conversation may generate humor.However, the greater likelihood is that the conversation engenders perplexity and disappointment in the interviewer. Rather like the characters in Evelyn Waugh's early novels, the philosopher is buffeted passively by life and luck and eschews agency or meaning. In Waugh's skilled hands this becomes tragic comedy; for the philosopher and his interlocutor we have disconnection and sadness. The crucial reason for this is that we need to use terms referring to moods, affects, meaning, and emotion when we offer an account of ourselves and when we try to understand ourselves. [End Page 267] Otherwise, something is missing and the reason a person gives for their actions either look like poor reasons or not reasons at all (Bortolotti and Broome 2008). Further, agency, rationality, and self-knowledge may themselves be dependent upon reason-giving.In invoking moods and affects in one's narrative the practical understanding (or ‘affordances’) of the world one inhabits are laid open in clear view. Hence Aristotle's account of wonder as the stimulus for philosophy. Aristotle says: ‘For it is owing to their wonder that men both now begin and at first began to philosophize; they wondered originally at the obvious difficulties, then advanced little by little and stated difficulties about the greater matters’ (1984, 1554). Conversely, given the experience of transcendence, of ambiguity, of finitude rather than wondrous awe, the philosopher may be motivated by anxiety (Kant's awakening from his dogmatic slumbers, Heidegger's battles with ‘Crisis’ and the flight of the gods). Either manner of accounting for one's interest seems to work normatively in the giving of reasons and in generating a narrative, and, moreover, a philosophical narrative.Our fictional dialogue and discussion aims to reinforce the important link between narrative, reason-giving and moods and affects argued for by Rosfort...

In lieu of an abstract, here is a brief excerpt of the content:Philosophy, Psychiatry, & Psychology 11.1 (2004) 35-41 [Access article in PDF] The Rationality of Psychosis and Understanding the Deluded Matthew R. Broome Campbell's important and influential paper (Campbell 2001) has framed the debate that Bayne and Pacherie (2004) most explicitly, and Klee (2004) and Georgaca (2004) more implicitly, engage in. Campbell has offered two broad ways of thinking about explanations of delusions—the empirical and the rational. He offers some criticism of the former and an endorsement of the latter. Campbell uses examples from clinical psychopathology to illustrate his argument and Bayne and Pacherie in turn employ these. Campbell discusses the eponymously named delusions of Capgras and Cotard—the former a subtype of delusional misidentification and the latter a delusion whose content is colored predominantly with nihilistic and possibly hypochondriacal themes. Campbell, Bayne and Pacherie, and Klee discuss the empirical data in relation to such delusions and as an aid to discussing the empirical model more generally. It does seem a little unfortunate that these delusions, which are less than typical, become the focus of Campbell's paper, and Bayne and Pacherie's criticism of his work. Delusions are remarkably heterogeneous; this indeed may be part of the reason why there is so much difficulty in reaching a definition as Klee discusses, and occur in a wide variety of mental and neurological illnesses. The most common delusions are those of persecution and reference (World Health Organization [WHO] 1973) and typically occur in schizophrenia. By contrast, delusional misidentification occurs most commonly in patients with dementia, delirium, and focal cognitive impairment, but can occur in other functional psychoses such as an affective or schizophrenic psychosis. The most common form of delusional misidentification is not that of either the exotic Capgras or Fregoli syndromes but delusional misidentification for place; thus, although Bayne and Pacherie's arguments against Campbell may still hold, delusional misidentification tends to occur in the context of a patient believing that they are at home or on holiday rather than in hospital and may not necessarily involve close family members or other intimate relationships. Similarly, Cotard's syndrome tends to occur in the context of a severe depressive illness with mood-congruent psychotic symptoms, typically in an elderly individual. It does not have to have the content that the deluded is dead, but can include beliefs, for example, that the world no longer exists or that their internal organs are not present. Thus, a patient with either Capgras' or Cotard's syndrome is likely to differ from patients with delusions of persecution. They would [End Page 35] have different diagnoses, probably be older, and have a greater likelihood of structural abnormalities of the brain on imaging and consequent neuropsychological dysfunction. That is not to say that patients with schizophrenia have normal cerebral anatomy and neuropsychology, but rather that the Capgras' and Cotard's patients are likely to have neurological quality to their presentation that is clinically relevant, rather than what commonly the case in schizophrenia and the other functional psychoses, where the neurological abnormalities are only currently important at the level of academic research. Empirical Models of Delusion Formation Different delusions may not have that much in common, nor may the patients who believe in them. This in turn relates to the empirical paradigm that both Campbell and Bayne and Pacherie discuss. It is true that current research, and indeed the clinical practice of cognitive behavioral therapy for psychosis, is indebted to the work of Maher and it is within his legacy which we work. This, however, is not to say that we think his initial formulation was correct. Maher's (1988, 1992) work focused attempts in explaining delusions—both to support and refute his thesis that delusions are the consequence of normal cognitive mechanisms seeking to explain an anomalous sensory experience. Such a view initially led to work demonstrating delusions in the absence of anomalous perceptions, the presence of reasoning biases in the deluded population, and the possibility that abnormal sensory experience may be consequent upon biased cognitive processes (Garety and Freeman 1999). More recent work has demonstrated the prevalence of...

In this paper, recent publications in the field of psychiatric nosology, classification, and diagnosis are reviewed. An attempt is made to group such writings into three broad themes: "essentialist/realist," "anti-essentialist/pragmatic," and "eliminative." The conceptual nature of these groupings is explored, and similarities between some elements of biological psychiatry and phenomenological psychiatry are outlined. The paper attempts to undercut current ways of thinking about psychiatric disorders by drawing on John McDowell's criticism of the idea of a value-free objective standpoint, and further relates our difficulties in thinking about mental disorders to McDowell's wider diagnosis of problems in contemporary philosophy.