Cognitive neuropsychiatry (CN) is the explanation of psychiatric disorder by the methods of cognitive neuropsychology. Within CN there are, broadly speaking, two approaches to delusion. The first uses a one-stage model, in which delusions are explained as rationalizations of anomalous experiences via reasoning strategies that are not, in themselves, abnormal. Two-stage models invoke additional hypotheses about abnormalities of reasoning. In this paper, I examine what appears to be a very strong argument, developed within CN, in favor of a twostage explanation (...) of the difference in content between the Capgras and Cotard delusions. That explanation treats them as alternative rationalizations of essentially the same phenomenology. I show, however, that once we distinguish the phenomenology (and the neuroetiology), a one-stage model is adequate. In the final section I make some more general remarks on the oneand two-stage models. (shrink)

We provide a battery of examples of delusions against which theoretical accounts can be tested. Then, we identify neuropsychological anomalies that could produce the unusual experiences that may lead, in turn, to the delusions in our battery. However, we argue against Maher’s view that delusions are false beliefs that arise as normal responses to anomalous experiences. We propose, instead, that a second factor is required to account for the transition from unusual experience to delusional belief. The second factor in the (...) aetiology of delusions can be described superficially as a loss of the ability to reject a candidate for belief on the grounds of its implausibility and its inconsistency with everything else that the patient knows. But we point out some problems that confront any attempt to say more about the nature of this second factor. (shrink)

Recreative Minds develops a philosophical theory of imagination that draws upon the latest work in psychology. This theory illuminates the use of imagination in coming to terms with art, its role in enabling us to live as social beings, and the psychological consequences of disordered imagination. The authors offer a lucid exploration of a fascinating subject.

In the course of the discussion, Professor Quine pinpoints the difficulties involved in translation, brings to light the anomalies and conflicts implicit in our ...

Although a common clinical phenomenon, delusions are difficult to explain and have a problematic conceptual status. Advances in understanding delusions have come from studies which involve detailed investigation of particular types of delusion. Some of this work is summarised, with the Capgras and Cotard delusions as specific examples. These are used to high-highlight questions for which there is the potential for fruitful dialogue with philosophers. Such questions include the criteria for deciding that a statement represents a belief, the extent to (...) which we integrate our beliefs into a coherent web, and the nature and limits of human rationality. (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)

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)

This paper describes and defends in detail a novel account of belief, an account inspired by Ryle's dispositional characterization of belief, but emphasizing irreducibly phenomenal and cognitive dispositions as well as behavioral dispositions. Potential externalist and functionalist objections are considered, as well as concerns motivated by the inevitably ceteris paribus nature of the relevant dispositional attributions. It is argued that a dispositional account of belief is particularly well-suited to handle what might be called "in-between" cases of believing - cases in (...) which it is neither quite right to describe a person as having a particular belief nor quite right to describe her as lacking it. (shrink)

Uttered language does not necessarily reflect the planned communications of schizophrenia patients, nor do their delusions necessarily reflect basic failures of inferential reasoning. The role of inhibitory failure in the production of speech and the role of primary experiences of discrepancy between intention and action, and between experience–based expectations and perceived realities account for many of the clinical phenomena that have led to the conclusion that these patients have a ‘thought’ disorder, or a ‘disturbed’ mind. The alternatives and the evidence (...) are summarized in this paper. (shrink)

For years a debate has raged within the various literatures of philosophy, psychiatry, and psychology over whether, and to what degree, the concepts that characterize psychopathology are social constructions that reflect cultural values. While the majority position among philosophers has been normativist, i.e., that the conception of a mental disorder is value-laden, a vocal and cogent minority have argued that psychopathology results from malfunctions that can be described by terminology that is objective and scientific. Scientists and clinicians have tended to (...) endorse the objectivist position, with some notable exceptions. (shrink)

After reviewing factors implicated in the generation of delusional beliefs, we conclude that whilst a perceptual aberration coupled with a particular type of attri‐butional bias may be necessary to explain the specific thematic content of a bizarre delusion, neither of these factors, whether in isolation or in combination, is sufficient to explain the presence of delusional beliefs. In contrast to bias models (theories which explain delusion formation in terms of extremes of normal reasoning biases), we advocate a deficit model of (...) delusion formation–that is, delusions arise when the normal cognitive system which people use to generate, evaluate, and then adopt beliefs is damaged. Mere bias we think inadequate to explain bizarre delusions which defy commonsense and persist despite overwhelming rational counter‐argument. In particular, we propose that two deficits must be present in the normal cognitive system to explain bizarre delusions: (1) there must be some damage to sensory and/or attentional‐orient‐ing mechanisms which causes an aberrant perception–this explains the bizarre content of the causal hypothesis generated to explain what is happening; and (2) there must also be a failure of normal belief evaluation–this explains why a hypothesis, implausible in the light of general commonsense, is adopted as belief. This latter deficit occurs, we suggest, when an individual is incapable of suspending the natural favoured status of direct first‐person evidence in order to critically evaluate hypotheses, given equal pri‐ority whether based on direct or indirect sources of information. In contrast, delusions with ‘ordinary’ content may arise when a single deficit of normal belief evaluation occurs in the context of an extreme (but normal) attentional bias, thus causing failure to critically evaluate hypotheses based on misperceptions and misintrepretations of ambiguous (but ordinary) first‐person experience. (shrink)

Cognitive neuropsychiatry (CN) is the explanation of psychiatric disorder by the methods of cognitive neuropsychology. Within CN there are, broadly speaking, two approaches to delusion. The first uses a one-stage model, in which delusions are explained as rationalizations of anomalous experiences via reasoning strategies that are not, in themselves, abnormal. Two-stage models invoke additional hypotheses about abnormalities of reasoning. In this paper, I examine what appears to be a very strong argument, developed within CN, in favor of a two-stage explanation (...) of the difference in content between the Capgras and Cotard delusions. That explanation treats them as alternative rationalizations of essentially the same phenomenology. I show, however, that once we distinguish the phenomenology (and the neuroetiology), a one-stage model is adequate. In the final section I make some more general remarks on the one- and two-stage models. (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.

Davidson attacks the intelligibility of conceptual relativism, i.e. of truth relative to a conceptual scheme. He defines the notion of a conceptual scheme as something ordering, organizing, and rendering intelligible empirical content, and calls the position that employs both notions scheme-content dualism. He argues that such dualism is untenable since: not only can we not parcel out empirical content sentence per sentence but also the notion of uninterpreted content to which several schemes are relative, and the related notion of a (...) theory ”fitting the evidence’, can be shown to lack intelligibility too. Davidson argues further that belief in incommensurable schemes or non-intertranslatable languages is possible only on violating a correct understanding of interpretability : if we succeed in interpreting someone else then we have shown there is no need to speak of two conceptual schemes, while if we fail ”there is no ground for speaking of two.’. (shrink)

Article copyright 2002. We provide a battery of examples of delusions against which theoretical accounts can be tested. Then we identify neuropsychological anomalies that could produce the unusual experiences that may lead, in turn, to the delusions in our battery. However, we argue against Maher's view that delusions are false beliefs that arise as normal responses to anomalous experiences. We propose, instead, that a second factor is required to account for the transition from unusual experience to delusional belief. The second (...) factor in the etiology of delusions can be described superficially as a loss of the ability to reject a candidate for belief on the grounds of its implausibility and its inconsistency with everything else that the patient knows, but we point out some problems that confront any attempt to say more about the nature of this second factor. (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)

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)

Ordinarily, if you say something like “I see a comet,” you might make a mistake about whether it is a comet that you see, but you could not be right about whether it is a comet but wrong about who is seeing it. There cannot be an “error of identification” in this case. In making a judgement like, “I see a comet,” there are not two steps, finding out who is seeing the thing and finding out what it is that (...) is being seen, so that you could go wrong at either step. The only place to go wrong is in your description of what is being seen. We usually take it that the same point applies to present-tense ascriptions to oneself of psychological states in general. You can get it wrong about which psychological state you are in, but you cannot get it right about the psychological state but wrong about whose psychological state it is. In contrast, in a room full of people, I might hear a noise and conclude, “Bill sneezed,” and in this case I could be wrong either about who it was that sneezed or about whether it was a sneeze, rather than say a death-rattle. (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)

Psychiatric treatment and diagnosis rests upon a richer conception of normativity than, for example, cognitive neuropsychology. This paper explores the role that considerations of rationality can play in defining this richer conception of normativity. It distinguishes two types of rationality and considers how each type can break down in different ways in delusional psychiatric disorders.

Elisabeth Pacherie is a research fellow in philosophy at Institut Jean Nicod, Paris. Her main research and publications are in the areas of philosophy of mind, psychopathology and action theory. Her publications include a book on intentionality (_Naturaliser_ _l'intentionnalité_, Paris, PUF, 1993) and she is currently preparing a book on action and agency.

A popular approach to monothematic delusions in the recent literature has been to argue that monothematic delusions involve broadly rational responses to highly unusual experiences. Campbell calls this the empiricist approach to monothematic delusions, and argues that it cannot account for the links between meaning and rationality. In place of empiricism Campbell offers a rationalist account of monothematic delusions, according to which delusional beliefs are understood as Wittgensteinian framework propositions. We argue that neither Campbell's attack on empiricism nor his rationalist (...) alternative to empiricism is successful. (shrink)

In the formative years of psychiatry Freud, Bleuler, and Jaspers all studied Daniel Paul Schreber's Memoirs of My Nervous Illness as a model of psychotic thought. Sass provides a nuanced interpretation of Schreber's Memoirs in the context of Wittgenstein's analysis of philosophical solipsism. A dauntless critic of the illusions of philosophy, Wittgenstein likened the speculative excesses of traditional metaphysics to mental illness. Sass observes that many of the "intellectual diseases" that Wittgenstein discerned - diseases involving detachment from social existence and (...) practical concerns, and exaggerated processes of abstraction and self-consciousness - have striking affinities with the symptoms of schizophrenia. Like the philosophical solipsist, the schizophrenic may define his or her own consciousness as the center of the universe - and may experience his or her delusional world as a product of that same consciousness. (shrink)

In 1910, Karl Jaspers wrote a seminal essay on morbid jealousy in which he laid the foundation for the psychopathological phenomenology that through his work and the work of Hans Gruhle and Kurt Schneider, among others, would become the ...

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.

In this ground breaking and controversial work Richard Bentall shatters the myths that surround madness. He shows there is no reassuring dividing line between mental health and mental illness.

In this essay, I focus on Ainslie's interesting and bold view of belief and on its implications for akratic belief.