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... (shrink)

Delusional beliefs have sometimes been considered as rational inferences from abnormal experiences. We explore this idea in more detail, making the following points. Firstly, the abnormalities of cognition which initially prompt the entertaining of a delusional belief are not always conscious and since we prefer to restrict the term “experience” to consciousness we refer to “abnormal data” rather than “abnormal experience”. Secondly, we argue that in relation to many delusions (we consider eight) one can clearly identify what the abnormal cognitive (...) data are which prompted the delusion and what the neuropsychological impairment is which is responsible for the occurrence of these data; but one can equally clearly point to cases where this impairments is present but delusion is not. So the impairment is not sufficient for delusion to occur. A second cognitive impairment, one which impairs the ability to evaluate beliefs, must also be present. Thirdly (and this is the main thrust of our chapter) we consider in detail what the nature of the inference is that leads from the abnormal data to the belief. This is not deductive inference and it is not inference by enumerative induction; it is abductive inference. We offer a Bayesian account of abductive inference and apply it to the explanation of delusional belief. (shrink)

Chris Frith has argued that a loss of the sense of agency is central to schizophrenia. This suggests a connection between hallucinations and delusions on the one hand, and the misidentification of the subject’s imaginings as perceptions and beliefs on the other. In particular, understanding the mechanisms that underlie imagination may help us to explain the puzzling phenomena of thought insertion and withdrawal. Frith sometimes states his argument in terms of a loss of metarepresentational capacity in schizophrenia. I argue that (...) this formulation is unhelpful. (shrink)

Linking the process of rational decision making to emotions, an award-winning scientist who has done extensive research with brain-damaged patients notes the dependence of thought processes on feelings and the body's survival-oriented regulators. 50,000 first printing.

Chris Frith has argued that a loss of the sense of agency is central to schizophrenia. This suggests a connection between hallucinations and delusions on the one hand, and the misidentification of the subject’s imaginings as perceptions and beliefs on the other. In particular, understanding the mechanisms that underlie imagination may help us to explain the puzzling phenomena of thought insertion and withdrawal. Frith sometimes states his argument in terms of a loss of metarepresentational capacity in schizophrenia. I argue that (...) this formulation is unhelpful. (shrink)

Short abstract (98 words). Reasoning is generally seen as a means to improve knowledge and make better decisions. However, much evidence shows that reasoning often leads to epistemic distortions and poor decisions. This suggests that the function of reasoning should be rethought. Our hypothesis is that the function of reasoning is argumentative. It is to devise and evaluate arguments intended to persuade. Reasoning so conceived is adaptive given humans’ exceptional dependence on communication and vulnerability to misinformation. A wide range of (...) evidence in the psychology of reasoning and decision making can be reinterpreted and better explained in the light of this hypothesis. (shrink)

After presenting and criticizing recent theoretical work on the nature of delusional belief, I argue that the works of the later Wittgenstein and Donald Davidson offer heretofore underappreciated insights into delusional belief. I distinguish two general kinds of delusion: pedestrian and stark. The former can be explained as cognitive mistakes of various kinds, whereas the latter I argue are necessarily inexplicable. This thesis requires the denial of the Davidsonian dogma that rationality is constitutive of mental content. I claim that the (...) dogma holds only for normal cognition and is violated precisely in the case of stark delusion. (shrink)

In _ Psychiatry in the Scientific Image, _Dominic Murphy looks at psychiatry from the viewpoint of analytic philosophy of science, considering three issues: how we should conceive of, classify, and explain mental illness. If someone is said to have a mental illness, what about it is mental? What makes it an illness? How might we explain and classify it? A system of psychiatric classification settles these questions by distinguishing the mental illnesses and showing how they stand in relation to one (...) another. This book explores the philosophical issues raised by the project of explaining and classifying mental illness. Murphy argues that the current literature on mental illness -- exemplified by the Diagnostic and Statistical Manual of Mental Disorders -- is an impediment to research; it lacks a coherent concept of the mental and a satisfactory account of disorder, and yields too much authority to commonsense thought about the mind. He argues that the explanation of mental illness should meet the standards of good explanatory practice in the cognitive neurosciences, and that the classification of mental disorders should group symptoms into conditions based on the causal structure of the normal mind. (shrink)

In this book, psychologists and philosophers describe and discuss a range of case studies of delusional beliefs, drawing out general lessons both for the cognitive architecture of the mind and for the notion of rationality, and exploring connections between the delusional beliefs that occur in schizophrenia and the flawed understanding of beliefs that is characteristic of autism.

We propose that typical schizophrenic delusions develop on the background of preexisting anomalies of self-experience. We argue that disorders of the Self represent the experiential core clinical phenomena of schizophrenia, as was already suggested by the founders of the concept of schizophrenia and elaborated in the phenomenological psychiatric tradition. The article provides detailed descriptions of the pre-psychotic or schizotypal anomalies of self-experience, often illustrated through clinical vignettes. We argue that delusional transformation in the evolution of schizophrenic psychosis reflects a global (...) reorganization of consciousness and existential reorientation, both of which radiate from a fundamental alteration of the Self. We critically address the contemporary cognitive approaches to delusion formation, often finding them inconsistent with the clinical features of schizophrenia or implausible from a phenomenological point of view. (shrink)

An examination of verbal hallucinations and thought insertion as examples of "alienated self-consciousness.".

Delusions play a fundamental role in the history of psychology, philosophy and culture, dividing not only the mad from the sane but reason from unreason. Yet the very nature and extent of delusions are poorly understood. What are delusions? How do they differ from everyday errors or mistaken beliefs? Are they scientific categories? In this superb, panoramic investigation of delusion Jennifer Radden explores these questions and more, unravelling a fascinating story that ranges from Descartes’s demon to famous first-hand accounts of (...) delusion, such as Daniel Schreber’s Memoirs of My Nervous Illness. Radden places delusion in both a clinical and cultural context and explores a fascinating range of themes: delusions as both individually and collectively held, including the phenomenon of folies á deux ; spiritual and religious delusions, in particular what distinguishes normal religious belief from delusions with religious themes; how we assess those suffering from delusion from a moral standpoint; and how we are to interpret violent actions when they are the result of delusional thinking. As well as more common delusions, such as those of grandeur, she also discusses some of the most interesting and perplexing forms of clinical delusion, such as Cotard and Capgras. (shrink)

One of the tasks that recent philosophy of psychiatry has taken upon itself is to extend the range of understanding to some of those aspects of psychopathology that Jaspers deemed beyond its limits. Given the fundamental difficulties of offering a literal interpretation of the contents of primary delusions, a number of alternative strategies have been put forward including regarding them as abnormal versions of framework propositions described by Wittgenstein in On Certainty. But although framework propositions share some of the apparent (...) epistemic features of primary delusions, their role in partially constituting the sense of inquiry rules out their role in helping to understand delusions. (shrink)

Although patient data have traditionally implicated the left prefrontal cortex in hypothesis generation, recent lesion data implicate right PFC in hypothesis generation tasks that involve set shifts. To test the involvement of the right prefrontal cortex in a hypothesis generation task involving set shifts, we scanned 13 normal subjects with fMRI as they completed Match Problems and a baseline task. In Match Problems subjects determined the number of possible solutions for each trial. Successful solutions are indicative of set shifts. In (...) the baseline condition subjects evaluated the accuracy of hypothetical solutions to match problems. A comparison of Match Problems versus baseline trials revealed activation in right ventral lateral PFC and left dorsal lateral PFC. A further comparison of successfully versus unsuccessfully completed Match Problems revealed activation in right ventral lateral PFC, left middle frontal gyrus and left frontal pole, thus identifying the former as a critical component of the neural mechanisms of set-shift transformation. By contrast, activation in right dorsal lateral PFC covaried as a function of the number of solutions generated in Match Problems, possibly due to increased working memory demands to maintain multiple solutions ‘on-line’, conflict resolution, or progress monitoring. These results go beyond the patient data by identifying the ventral lateral aspect of right PFC as being a critical component of the neural systems underlying lateral transformations, and demonstrate a dissociation between right VLPFC and DLPFC in hypotheses generation and maintenance. (shrink)

Four detailed cases of delusions of misidentification (DM) are presented: two cases of misidentification of the reflected self, one of reverse intermetamorphosis, and one of reduplicative paramnesia. The cases are discussed in the context of three levels of interpretation: neurological, cognitive and phenomenological. The findings are compared to previous work with DM patients, particularly the work of Ellis and Young (1990; Young, 1998) who found that loss of the normal affective response to familiar faces was a contributing factor in the (...) Capgras delusion. The four cases presented suggest that this particular deficit is not a critical factor in the development of other forms of DM. (shrink)

Circumscribed delusional beliefs can follow brain injury. We suggest that these involve anomalous perceptual experiences created by a deficit to the person's perceptual system, and misinterpretation of these experiences due to biased reasoning. We use the Capgras delusion (the claim that one or more of one's close relatives has been replaced by an exact replica or impostor) to illustrate this argument. Our account maintains that people voicing this delusion suffer an impairment that leads to faces being perceived as drained of (...) their normal affective significance, and an additional reasoning bias that leads them to put greater weight on forming beliefs that are observationally adequate rather than beliefs that are a conservative extension of their existing stock. We show how this position can integrate issues involved in the philosophy and psychology of belief, and examine the scope for mutually beneficial interaction. (shrink)

Dream is a state of consciousness characterized by internally-generated sensory, cognitive and emotional experiences occurring during sleep. Dream reports tend to be particularly abundant, with complex, emotional, and perceptually vivid experiences after awakenings from rapid eye movement sleep. This is why our current knowledge of the cerebral correlates of dreaming, mainly derives from studies of REM sleep. Neuroimaging results show that REM sleep is characterized by a specific pattern of regional brain activity. We demonstrate that this heterogeneous distribution of brain (...) activity during sleep explains many typical features in dreams. Reciprocally, specific dream characteristics suggest the activation of selective brain regions during sleep. Such an integration of neuroimaging data of human sleep, mental imagery, and the content of dreams is critical for current models of dreaming; it also provides neurobiological support for an implication of sleep and dreaming in some important functions such as emotional regulation. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Philosophy, Psychiatry, & Psychology 11.1 (2004) 71-80 [Access article in PDF] Some Reflections on the (Analytic) Philosophical Approach to Delusion Louis A. Sass There are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy." —Hamlet, Act I, Scene 5 The peculiar, often problematic phenome na of psychopathology have been attract ing the attention of analytic philosophers in recent years. The topic of delusion has (...) been a particular draw, with a number of analytic philosophers attempting to use their conceptual tools, usually combined with ideas from cognitive neuroscience, to criticize the traditional understanding and to clarify the nature of this central psychiatric topic. It is useful to have this kind of interdisciplinary dialogue. Indeed, there is good reason to hope that concepts honed in the philosophy of mind and other philosophical subfields will help to sort out our understanding of a phenomenon (or set of phenomena) for which contemporary psychiatric definitions and conceptualizations are clearly inadequate and, in some respects, downright misleading (see Parnas and Sass 2001; Spitzer 1990).1Here, however, I would like to call attention to some weaknesses that, it seems to me, are rather common (I do not say universal) in many analytic philosophical approaches to psychopathology. In my opinion, there is a tendency to formulate issues and arguments in overly polarized, even dichotomous terms, and then to rely too uncritically on these essentialistic formulations in exploring the domain of inquiry. Although this polarizing tendency sometimes has the salutary effect of clarifying conceptual domains, it can, when taken too far, actually hamper our understanding of phenomena that are often fraught with ambiguities and complexities that defy many standard conceptualizations.The relationship between philosophy and psychopathology is obviously a two-way street—we are familiar, for example, with disorders that challenge deep philosophical assumptions about self and mind (e.g., blindsight, split-brain phenomena, perhaps also Dissociative Identity Disorder, and the first rank symptoms of schizophrenia). I am suggesting that, in their work on delusions, philosophers may need to put more emphasis on moving from the natural phenomena [End Page 71] of psychopathology and to the domain of philosophical analysis.I believe that a greater sensitivity to the modes of knowing associated with the phenomenological tradition, and to the forms of conceptual self-critique fostered by Ludwig Wittgenstein, are crucial ingredients for any adequate approach to delusion as well as many other topics in psychopathology. In my opinion, the work of many analytic philosophers interested in psychopathology would be enriched if they spent more time trying to discover and imagine what it might be like to experience certain kinds of abnormal psychiatric conditions, and also speculating about what implications such experiential modalities might have for action and verbal expression. I believe they would also be wise to spend more time questioning, and attempting to transcend, the philosophically derived conceptual distinctions and dichotomies that appear to organize their conceptual universes. Phenomenological imagination and Wittgensteinian critique can show how to move outside the conceptual capsule and into the rich and strange realms of actual experience, both normal and abnormal.So far I have offered only slogans. Let me use the articles by Tim Bayne and Elisabeth Pacherie (2004) and Robert Klee (2004) to flesh out the criticisms I have offered. There is much that is intelligent and much that is worthwhile in both their articles. (For example, I was largely convinced by the criticisms of John Campbell and of Donald Davidson that are central to the articles by Bayne and Pacherie and by Klee, respectively.) Here, however, I will focus only on issues that illustrate the above-mentioned tendencies—tendencies that, in my view, tend to infect even the best writings on the (analytic) philosophy of psychiatry. I will also make some remarks about the works of Campbell and Davidson, the two philosophers criticized in the articles by Bayne and Pacherie and by Klee. Because the article by Eugenie Georgaca (2004) is in a different tradition, I will say only a few words about it at the end. Bayne and Pacherie on the Preservation-Of-meaning... (shrink)