In this paper we defend the doxastic conception of delusions against the metacognitive account developed by Greg Currie and collaborators. According to the metacognitive model, delusions are imaginings that are misidentified by their subjects as beliefs: the Capgras patient, for instance, does not believe that his wife has been replaced by a robot, instead, he merely imagines that she has, and mistakes this imagining for a belief. We argue that the metacognitive account is untenable, and that the traditional conception of (...) delusions as beliefs should be retained. (shrink)

How many factors, i.e. departures from normality, are necessary to explain a delusion? Maher’s classic one-factor theory argues that the only factor is the patient’s anomalous experience, and a delusion arises as a normal explanation of this experience. The more recent two-factor theory, on the other hand, contends that a second factor is also needed, with reasoning abnormality being a potential candidate, and a delusion arises as an abnormal explanation of the anomalous experience. In the past few years, although there (...) has been an increasing number of scholars offering a variety of arguments in defence of Maher’s one-factor theory, these arguments have not been adequately addressed by two-factor theorists. This paper aims to address this gap by critically examining the arguments on three crucial issues: the intelligibility of delusions, the dissociation between anomalous experiences and delusions, and the empirical evidence of a second factor. I will argue that the Maherian notion of anomalous experience is not sufficient for explaining delusions and the two-factor theory is on the right track in its search for the missing factor in the aetiology of delusions. (shrink)

According to the Rationality Constraint, our concept of belief imposes limits on how much irrationality is compatible with having beliefs at all. We argue that empirical evidence of human irrationality from the psychology of reasoning and the psychopathology of delusion undermines only the most demanding versions of the Rationality Constraint, which require perfect rationality as a condition for having beliefs. The empirical evidence poses no threat to more relaxed versions of the Rationality Constraint, which only require only minimal rationality. Nevertheless, (...) we raise problems for all versions of the Rationality Constraint by appealing to more extreme forms of irrationality that are continuous with actual cases of human irrationality. In particular, we argue that there are conceivable cases of “mad belief” in which populations of Lewisian madmen have beliefs that are not even minimally rational. This undermines Lewis’s claim that our ordinary concept of belief is a theoretical concept that is implicitly defined by its role in folk psychology. We argue that introspection gives us a phenomenal concept of belief that cannot be analyzed by applying Lewis’s semantics for theoretical terms. (shrink)

Bortolotti’s Delusions and Other Irrational Beliefs defends the view that delusions are beliefs on a continuum with other beliefs. A different view is that delusions are more like illusions, that is, they arise from faulty perception. This view, which is not targeted by the book, makes it easier to explain why delusions are so alien and disabling but needs to appeal to forensic aspects of functioning.

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)

Psychopathological delusions have a number of features that are curiously difficult to explain. Delusions are resistant to counterevidence and impervious to counterargument. Delusions are theoretically, affectively, and behaviorally circumscribed: delusional individuals often do not act on their delusions and often do not update beliefs on the basis of their delusions. Delusional individuals are occasionally able to distinguish their delusions from other beliefs, sometimes speaking of their “delusional reality.” To explain these features, I offer a model according to which, contrary to (...) appearances, delusions are not beliefs at all. Delusions are acceptances that are generated by pathologically powerful cognitive feelings. This model has implications for the way that we should think about non-pathological doxastic states and emotions. (shrink)

Three challenges to a unified understanding of delusions emerge from Radden's On Delusion (2011). Here, I propose that in order to respond to these challenges, and to work towards a unifying framework for delusions, we should see delusions as arising in inference under uncertainty. This proposal is based on the observation that delusions in key respects are surprisingly like perceptual illusions, and it is developed further by focusing particularly on individual differences in uncertainty expectations.

Stanford Encyclopedia Entry on Delusions.

Some monothematic types of delusions may arise because subjects have unusual experiences. The role of this experiential component in the pathogenesis of delusion is still not understood. Focussing on delusions of alien control, we outline a model for reality testing competence on unusual experiences. We propose that nascent delusions arise when there are local failures of reality testing performance, and that monothematic delusions arise as normal responses to these. In the course of this we address questions concerning the tenacity with (...) which delusions are maintained, their often bizarre content, the patients' inability to dismiss them, and their often circumscribed character. (shrink)

Abstract: How it is that one's own thoughts can seem to be someone else's? After noting some common missteps of other approaches to this puzzle, I develop a novel cognitive solution, drawing on and critiquing theories that understand inserted thoughts and auditory verbal hallucinations in schizophrenia as stemming from mismatches between predicted and actual sensory feedback. Considerable attention is paid to forging links between the first-person phenomenology of thought insertion and the posits (e.g. efference copy, corollary discharge) of current cognitive (...) theories. I show how deficits in the subconscious mechanisms regulating inner speech may lead to a 'fractured phenomenology' responsible for schizophrenic patients' reports of inserted thoughts and auditory verbal hallucinations. Supporting work on virtual environments is discussed, and lessons concerning the fixity of delusional belief are drawn. (shrink)

How is it that many schizophrenics identify certain instances of verbal imagery as hallucinatory? Most investigators have assumed that alterations in sensory features of imagery explain this. This approach, however, has not yielded a definitive picture of the nature of verbal hallucinations. An alternative perspective suggests itself if one allows the possibility that the nonself quality of hallucinations is inferred on the basis of the experience of unintendedness that accompanies imagery production. Information-processing models of “intentional” cognitive processes call for abstract (...) planning representations that are linked to goals and beliefs. Unintended actions - and imagery - can reflect planning disruptions whereby cognitive products do not cohere with concurrent goals. A model of schizophrenic speech disorganization is presented that postulates a disturbance of discourse planning. Insofar as verbal imagery can be viewed as inwardly directed speech, a consequence of such planning disturbances could be the production of unintended imagery. This link between the outward disorganization of schizophrenic speech and unintended verbal imagery is statistically supported by comparing the speech behavior of hallucinating and nonhallucinating schizophrenics. Studies of “borderline” hallucinations during normal, “goal-less” relaxation and drowsiness suggest that experiential unintendedness leads to a nonpathological variant of hallucinatory otherness that is correctable upon emerging from such passive cognitive states. This contrasts with the schizophrenic case, where nonconcordance with cognitive goals reinforces the unintendedness of verbal images and sustains the conviction of an external source. This model compares favorably with earlier models of verbal hallucinations and provides further evidence for a language production disorder in many schizophrenics.Short Abstract: How is it that many schizophrenics identify certain instances of verbal imagery as hallucinatory? This paper proposes that the critical feature identifying hallucinations is the experience of unintendedness. This experience is nonpathological during passive conscious states but pathological if occurring during goal-directed cognitive processing. A model of schizophrenic speech disorganization is presented that postulates a disturbance of discourse planning that specifies communicative intentions. These alterations could generate unintended verbal imagery as well. Statistical data are offered to support the model, and relevant empirical studies are reviewed. (shrink)

Monothematic delusions involve a single theme, and often occur in the absence of a more general delusional belief system. They are cognitively atypical insofar as they are said to be held in the absence of evidence, are resistant to correction, and have bizarre contents. Empiricism about delusions has it that anomalous experience is causally implicated in their formation, whilst rationalism has it that delusions result from top down malfunctions from which anomalous experiences can follow. Within empiricism, two approaches to the (...) nature of the abnormality/abnormalities involved have been touted by philosophers and psychologists. One-factor approaches have it that monothematic delusions are a normal response to anomalous experiences whilst two-factor approaches seek to identify a clinically abnormal pattern of reasoning in addition to anomalous experience to explain the resultant delusion. In this paper we defend a one-factor approach. We begin by making clear what we mean by atypical, abnormal, and factor. We then identify the phenomenon of interest and overview one and two-factor empiricism about its formation. We critically evaluate the cases for various second factors, and find them all wanting. In light of this we turn to our one-factor account, identifying two ways in which ‘normal response’ may be understood, and how this bears on the discussion of one-factor theories up until this point. We then conjecture that what is at stake is a certain view about the epistemic responsibility of subjects with delusions, and the role of experience, in the context of familiar psychodynamic features. After responding to two objections, we conclude that the onus is on two-factor theorists to show that the one-factor account is inadequate. Until then, the one-factor account ought to be understood as the default position for explaining monothematic delusion formation and retention. We don’t rule out the possibility that, for particular subjects with delusions there may be a second factor at work causally implicated in their delusory beliefs but, until the case for the inadequacy of the single factor is made, the second factor is redundant and fails to pick out the minimum necessary for a monothematic delusion to be present. (shrink)

Empiricist models explain delusional beliefs by identifying the abnormal experiences which ground them. Recently, this strategy has been adopted to explain the false body size beliefs of anorexia nervosa patients. As such, a number of abnormal experiences of body size which patients suffer from have been identified. These oversized experiences convey false information regarding the patients’ own bodies, indicating that they are larger than reality. However, in addition to these oversized experiences, patients are also exposed to significant evidence suggesting their (...) bodies are in fact thin. This situation poses a conundrum: why do patients appear strongly influenced by the former kinds of evidence while the latter has little effect? To solve this conundrum, I suggest a two-factor account. First, I discuss research on the biases patients exhibit in how they gather, attend to and interpret evidence related to their own body size. Such biases in evidence treatment, I suggest, cause oversized experiences to be sought out, attended to and accepted, while veridical body size experiences are ignored or explained away. These biases constitute the second factor for this empiricist model, accounting for the unwarranted conviction with which these beliefs are held. Finally, in line with recent research into self-deception, I propose that, paradoxically, these biases in evidence treatment arise from patients’ own desires. (shrink)

An examination of alien abduction belief can inform how we ought to approach constructing explanations of monothematic delusion formation. I argue that the formation and maintenance of alien abduction beliefs can be explained by a one-factor account, and that this explanatory power generalizes to (other) cases of monothematic delusions. There are no differences between alien abduction beliefs and monothematic delusions which indicate the need for additional explanatory factors in cases of the latter. I make the additional point that whilst alien (...) abduction beliefs can be readily explained using a one-factor framework, the two-factor framework requires adjustment to accommodate them. I conclude that theorists interested in delusion formation have much to learn from the case of alien abduction belief. (shrink)

On one influential view, the problems that should attract medical attention involve a disorder, because the goals of medical practice are to prevent and treat disorders. Based on this view, if there are no mental disorders then the status of psychiatry as a medical field is challenged. In this paper, I observe that it is often difficult to establish whether the problems that attract medical attention involve a disorder, and argue that none of the notions of disorder proposed so far (...) offers a successful demarcation criterion between medical and non-medical problems. As an illustration, I consider why delusions are considered pathological and whether they attract medical attention in virtue of being pathological, where ‘pathological’ stands for ‘being caused by a disorder’. Although there are several promising answers to what makes delusions pathological, available accounts of the pathological nature of delusions fail to distinguish delusions from other irrational beliefs that are not typically thought of as pathological; and cannot explain why delusions typically attract medical attention whereas other irrational beliefs do not. (shrink)

This essay presents a new account of thought insertion. Prevailing views in both philosophy and cognitive science tend to characterize the experience of thought insertion as missing or lacking some element, such as a ‘sense of agency’, found in ordinary first-person awareness of one's own thoughts. By contrast, I propose that, rather than lacking something, experiences of thought insertion have an additional feature not present in ordinary conscious experiences of one's own thoughts. More specifically, I claim that the structure of (...) an experience of thought insertion consists of two distinct elements: a state of ordinary first-person awareness and a sense that this state of awareness is highly unusual. In addition to modeling the experience of thought insertion, I also explain how a delusional pattern of thinking could lead someone who has this kind of experience to adopt a belief that some other entity is inserting thoughts into her mind. Finally, I briefly sketch a neurocomputational framework that could be developed to explain the sense that one's state of first-person awareness is highly irregular. (shrink)

I argue that some cases of delusions show the inadequacy of those theories of interpretation that rely on a necessary rationality constraint on belief ascription. In particular I challenge the view that irrational beliefs can be ascribed only against a general background of rationality. Subjects affected by delusions seem to be genuine believers and their behaviour can be successfully explained in intentional terms, but they do not meet those criteria that according to Davidson (1985a) need to be met for the (...) background of rationality to be in place. (shrink)

In this paper we review two debates in the current literature on clinical delusions. One debate is about what delusions are. If delusions are beliefs, why are they described as failing to play the causal roles that characterise beliefs, such as being responsive to evidence and guiding action? The other debate is about how delusions develop. What processes lead people to form delusions and maintain them in the face of challenges and counter-evidence? Do the formation and maintenance of delusions require (...) abnormal experience alone, or also reasoning biases or deficits? We hope to show that the focus on delusions has made a substantial contribution to the philosophy of the mind and continues to raise issues that are central to defining the concept of belief and gaining a better understanding of how people process information and learn about the world. (shrink)

Delusional beliefs are typically pathological. Being pathological is clearly distinguished from being false or being irrational. Anna might falsely believe that his husband is having an affair but it might just be a simple mistake. Again, Sam might irrationally believe, without good evidence, that he is smarter than his colleagues, but it might just be a healthy self-deceptive belief. On the other hand, when a patient with brain damage caused by a car accident believes that his father was replaced by (...) an imposter or another patient with schizophrenia believes that “The Organization” painted the shops on a street in red and green to convey a message, these beliefs are not merely false or irrational. They are pathological. What makes delusions pathological? This paper explores the negative features because of which delusional beliefs are pathological. First, I critically examine the proposals according to which delusional beliefs are pathological because of (1) their strangeness, (2) their extreme irrationality, (3) their resistance to folk psychological explanations or (4) impaired responsibility-grounding capacities of people with them. I present some counterexamples as well as theoretical problems for these proposals. Then, I argue, following Wakefield’s harmful dysfunction analysis of disorder, that delusional beliefs are pathological because they involve some sorts of harmful malfunctions. In other words, they have a significant negative impact on wellbeing (=harmful) and, in addition, some psychological mechanisms, directly or indirectly related to them, fail to perform the jobs for which they were selected in the past (=malfunctioning). An objection to the proposal is that delusional beliefs might not involve any malfunctions. For example, they might be playing psychological defence functions properly. Another objection is that a harmful malfunction is not sufficient for something to be pathological. For example, false beliefs might involve some malfunctions according to teleosemantics, a popular naturalist account of mental content, but harmful false beliefs do not have to be pathological. I examine those objections in detail and show that they should be rejected after all. (shrink)

In both cognitive science and philosophy, many theorists have recently appealed to a predictive processing framework to offer explanations of why certain individuals form delusional beliefs. One aim of this essay will be to illustrate how one could plausibly develop a predictive processing account in different ways to account for the onset of different kinds of delusions. However, the second aim of this essay will be to discuss two significant limitations of the predictive processing framework. First, I shall draw on (...) the structure of explanatory why-questions to argue that predictive processing theories can only partially explain the formation of delusional beliefs. Second, I shall argue that predictive processing theories cannot explain how implausible delusional hypotheses are generated. Yet understanding why an agent even generates a delusional hypothesis is a crucial step to understanding why she eventually comes to believe it. The final section of the essay presents three alternative ways the process of hypothesis generation might be functionally divergent in cases of delusional cognition. (shrink)

In his recent book Delusions and Beliefs, Kengo Miyazono offers a thoroughgoing defence of delusions as biologically malfunctioning beliefs, greatly elaborating on his earlier defence of this view. Miyazono has it that delusions have biological doxastic functions, and that delusions involve direct or indirect malfunctions of this kind. In this short piece, I focus on Miyazono’s defence of a two-factor approach to delusion formation as it appears in Chapter Four. Miyazono approaches his discussion of the debate between one- and two-factor (...) theories having already defended the key thesis of the book: that delusions are malfunctioning beliefs. Of course, that thesis might be thought to mesh nicely with the two-factor theorist’s claim that there is a cognitive abnormality present in delusion formation or maintenance. However, I will discuss Miyazono’s defence of the two-factor position in isolation from its role in his overall account of delusion. Miyazono abstracts away from the particulars of Max Coltheart’s two-factor view, and takes himself to be investigating the plausibility of two-factor theories without the specific commitments of Coltheart’s view. Miyazono also captures under the two-factor heading theories which locate the second factor in belief maintenance rather than just in belief formation. He puts forward a new argument for a two-factor approach which goes via inference to the best explanation. I begin by arguing that Miyazono’s starting motivation for a two-factor approach rests on a misrepresentation of the one-factor approach. Then, I turn to the four components of Miyazono’s inference to the best explanation argument, and argue that in each case, we do not have grounds for positing a second factor. (shrink)

Current models of delusion converge in proposing that delusional beliefs are based on unusual experiences of various kinds. For example, it is argued that the Capgras delusion (the belief that a known person has been replaced by an impostor) is triggered by an abnormal affective experience in response to seeing a known person; loss of the affective response to a familiar person’s face may lead to the belief that the person has been replaced by an impostor (Ellis & Young, 1990). (...) Similarly, the Cotard delusion (which involves the belief that one is dead or unreal in some way) may stem from a general.. (shrink)

In chapter 3 of Delusions and Beliefs, Kengo Miyazono argues that, when delusions are pathological beliefs, they are so due to their being both harmful and malfunctional. In this brief commentary, I put pressure on Miyazono’s account of delusions as harmful malfunctioning beliefs. No delusions might satisfy the malfunction criterion and some delusions might fail to satisfy the harmfulness criterion when such conditions are interpreted as criteria for pathological beliefs. In the end, I raise a general concern about attributing pathological (...) status to single beliefs out of context, and gesture towards the idea of pathology as a failure of agency to which some beliefs can contribute but that can only be identified by considering the person as a whole. (shrink)

Chenwei Nie ([22]) argues against a Maherian one-factor approach to explaining delusion. We argue that his objections fail. They are largely based on a mistaken understanding of the approach (as committed to the claim that anomalous experience is sufficient for delusion). Where they are not so based, they instead rest on misinterpretation of recent defences of the position, and an underestimation of the resources available to the one-factor theory.

Just as sadness is not always a symptom of mood disorder, irrational beliefs are not always symptoms of illness. Pathological irrational beliefs are distinguished from non-pathological ones by considering whether their existence is best explained by assuming some underlying dysfunctions. The features from which to infer the pathological nature of irrational beliefs are: un-understandability of their progression; uniqueness; coexistence with other psycho-physiological disturbances and/or concurrent decreased levels of functioning; bizarreness of content; preceding organic diseases known to be associated with irrational (...) beliefs; treatment response to medical intervention, etc. Severe irrationality is sometimes caused by normal human motivation rather than by mental or physical dysfunction. Pure forms of self-deception may satisfy the diagnostic criteria of delusional disorder, but there may be no evidence that suggests that they are caused by illness. Although those with pathological delusions do not recognize their delusions as symptomatic of illness, differentiating pathological beliefs from normal irrational beliefs is vitally important: If a belief is pathological, psychiatrists must seriously consider treating the patient against her will. If it is not pathological, conversely, involuntary treatments are prohibited because they offend her basic autonomy. (shrink)

Delusions are usually considered as harmful and dysfunctional beliefs, one of the primary symptoms of a psychiatric illness and the mark of madness in popular culture. However, in recent times a much more positive role has been advocated for delusions. More specifically, it has been argued that delusions might be an answer to a problem rather than problems in themselves. By delivering psychological and epistemic benefits, delusions would allow people who face severe biological or psychological difficulties to survive in their (...) environment - although this has obvious epistemic costs, as the delusion is fixed and irresponsive to compelling counterevidence. In other words, it has been argued that delusions are biologically adaptive. The adaptiveness of delusions has been compared by Ryan McKay and Daniel Dennett to a shear pin, a mechanism installed in the drive engine of some machines which is designed to shear whenever the machine is about to break down. By breaking, shear pins prevent the machine from collapsing and allow it to keep functioning, although in an impaired manner. Similarly, when delusions form, they would allow a cognitive or psychological system which is about to collapse to continue its functioning, although in an impaired manner. However, this optimistic picture of delusions risks being undermined by both theoretical and empirical considerations. Using Sarah Fineberg and Philip Corlett’s recent predictive coding account as a paradigmatic model of the biological adaptiveness of delusions, I develop two objections to it: principles of parsimony and simplicity suggest that maladaptive models of delusions have an upper hand over adaptive models; and the available empirical evidence suggests that at least some delusions stand good chances of being psychologically adaptive, but it is unlikely that they also qualify as biologically adaptive. (shrink)

ABSTRACTEmpiricists about monothematic delusion formation agree that anomalous experience is a factor in the formation of these attitudes, but disagree markedly on which further factors need to be specified. I argue that epistemic innocence may be a unifying feature of monothematic delusions, insofar as a judgment of epistemic innocence to this class of attitudes is one that opposing empiricist accounts can make. The notion of epistemic innocence allows us to tell a richer story when investigating the epistemic status of monothematic (...) delusions, one which resists the trade-off view of pragmatic benefits and epistemic costs. Though monothematic delusions are often characterized by appeal to their epistemic costs, they can play a positive epistemic role, and this is a surprising conclusion on which, so I argue, all empiricists can agree. Thus, I show that all empiricists have the notion of epistemic innocence at their disposal. (shrink)

Despite the diagnostic relevance of thought insertion for disorders such as schizophrenia, the debates about its aetiology are far from resolved. This paper claims that in paying exclusive attention to the perceptual and cognitive impairments leading to delusional experiences in general, current deficit approaches overlook the role that affective disturbances might play in giving rise to cases of thought insertion. In the context of psychosis, affective impairments are often characterized as a consequence of the stress and anxiety caused by delusional (...) episodes. However, here I explore some of the conceptual and empirical reasons to think that affective problems might in fact play a crucial doxastic role in the aetiology of thought insertion. Finally, I conclude by proposing a way of integrating the main insights of my analysis with the current ‘two-factor’ deficit approach to thought insertion and I explore the potential adaptive role that some delusions might have within this framework. (shrink)

Maher proposed in 1974 that schizophrenic delusions are hypotheses formed to explain anomalous experiences. He stated that they are “rational, given the intensity of the experiences that they are developed to explain.” Two-factor theorists of delusion criticized Maher’s theory because 1) it does not explain why some patients with anomalous experiences do not develop delusions, and 2) adopting and adhering to delusional hypotheses is irrational, considering the totality of experiences and patients’ other beliefs. In this paper, the notion of the (...) intensity of experience is reappraised to uphold Maher’s basic conception. Regarding 1), I propose that differences in the intensity of anomalous experience are vital to whether the patient forms delusions, while partially reforming his rationality claim regarding 2). Although adopting delusions is irrational, it is inevitable and excusable, given the intensity of the patient’s anomalous experience. With the aid of this notion, it is maintained that anomalous experience is sufficient for the development of delusions, at least in some cases of schizophrenia. Compared to other theories of schizophrenic delusion, Maher’s theory, which embraces the notion of intensity of experience, better explains why such irrational mental states as delusions develop from anomalous experiences, and why delusional patients persist in believing specific thematic content. (shrink)

Delusional misidentification is commonly understood as the product of an inference on the basis of evidence present in the subject's experience. For example, in the Capgras delusion, the patient sees someone who looks like a loved one, but who feels unfamiliar, so they infer that they must not be the loved one. I question this by presenting a distinction between “recognition” and “identification.” Identification does not always require recognition for its epistemic justification, nor does it need recognition for its psychological (...) functioning. Judgments of identification are often the product of a non-inferential mechanism. Delusional misidentification arises as the product of this mechanism malfunctioning. (shrink)

In this paper I discuss the role played by disturbed phenomenology in accounting for the formation and maintenance of the Capgras delusion. Whilst endorsing a two-stage model to explain the condition, I nevertheless argue that traditional accounts prioritise the role played by some form of second-stage cognitive disruption at the expense of the significant contribution made by the patient’s disturbed phenomenology, which is often reduced to such uninformative descriptions as “anomalous” or “strange”. By advocating an interactionist model, I argue that (...) the delusional belief constitutes an attempt on the part of the patient to explain his/her initially odd and somewhat disturbed phenomenal content and, moreover, that the delusion then structures the patient’s experience such that what he/she perceives is an impostor. This fact is used to explain the delusional belief’s maintenance and resistance to revision. Thus, whilst accepting that second-stage cognitive disruption has a part to play in explaining the Capgras delusion, the emphasis here is placed on the role played by the patient’s changing phenomenal content and its congruence with the delusional belief. Unlike traditional two-stage models, which posit a unidirectional progression from experience to belief, the interactionist model advocates a two-way interaction between bottom-up and top-down processes. The application of this model to other delusional beliefs is also considered. (shrink)

The dominant conception of delusion in psychiatry (in textbooks, research papers, diagnostic manuals, etc.) is predominantly epistemic. Delusions are almost always characterized in terms of their epistemic defects, i.e., defects with respect to evidence, reasoning, judgment, etc. However, there is an individualistic bias in the epistemic conception; the alleged epistemic defects and abnormalities in delusions relate to individualistic epistemic processes rather than social epistemic processes. We endorse the social epistemological turn in recent philosophical epistemology, and claim that a corresponding turn (...) is needed in the study of delusions. It is a turn from the (purely) individualistic conception, which characterizes delusions only by individualistic epistemic defects and abnormalities, to the (partially) social epistemic conception, which characterizes delusions by individualistic as well as social epistemic defects and abnormalities. This paper is intended as an initial step toward such a social epistemological turn. In particular, we will develop a new model of the development of delusions according to which testimonial abnormalities, including testimonial isolation and testimonial discount, are a causal factor in the development of delusions. (shrink)

Standard accounts of delusion explain them as responses to experience. Cognitive models of feature binding in the face recognition systems explain how experiences of mismatch between feelings of "familiarity" and faces can arise. Similar mismatches arise in phenomena such as déjà and jamais vu in which places and scenes are mismatched to feelings of familiarity. These cognitive models also explain similarities between the phenomenology of these delusions and some dream states which involve mismatch between faces, feelings of familiarity and identities. (...) Given these similarities it makes sense to retain that aspect of the standard account in the face of revisionist arguments that feature binding anomalies which lead to delusions of misidentification are not consciously experienced. (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)

Anorexia nervosa involves seemingly irrational beliefs about body size and the value of thinness. Historically, researchers and clinicians have avoided referring to such beliefs as delusions, instead opting for the label ‘overvalued ideas’. I discuss the relationship between the beliefs associated with anorexia nervosa and the distinction between delusions and overvalued ideas, as it is conceived in both European and American psychiatric traditions. In doing so, I question the benefit of applying the concepts of delusion and overvalued idea to anorexia (...) nervosa and raise some issues with contemporary use of the Brown Assessment of Beliefs scale for assessing the level of delusionality associated with the disorder. (shrink)

Contemporary perspectives on delusions offer valuable neuropsychiatric, psychoanalytic, and philosophical explanations of the formation and persistence of delusional phenomena. However, two problems arise. Firstly, these different perspectives offer us an explanation “from the outside”. They pay little attention to the actual personal experiences, and implicitly assume their incomprehensibility. This implicates a questionable validity. Secondly, these perspectives fail to account for two complex phenomena that are inherent to certain delusions, namely double book-keeping and the primary delusional experience. The purpose of this (...) article is to address both problems, by offering an understanding “from the inside”. Our phenomenological approach is a form of “radical empathy”, and crosses the Jaspersian limits of understanding. It compares delusional experiences with variations of reality experience in everyday life, and makes use of the structure of imagination. Six factors influencing the experience of reality are discussed and illustrated by clinical and non-clinical examples. These factors are: continuity, materiality and resistance, multiplicity of sensations and perceptions, intensity, the sense of authorship, and the complex role of intersubjectivity. I suggest that experiences of hypo- and hyperreality are not restricted to pathology, but have their place in everyday life as well. Delusional phenomena can be better understood by investigating the interplay of these six factors. With this framework, the two complex phenomena consequently prove to be better understandable to us. Our approach remains within the phenomenal experience and might thereby contribute to the validity of psychopathology. (shrink)

In his classic paper, “Delusional thinking and perceptual disorder,” Brendan Maher (1974) argues that psychiatric delusions are hypotheses designed to explain anomalous experiences, and are “developed through the operation of normal cognitive processes.” Consider, for instance, the Capgras delusion. Patients suffering from this particular delusion believe that someone close to them—such as a spouse, a sibling, a parent, or a child—has been replaced by an impostor: by someone who bears a striking resemblance to the “original” and who (for reasons unknown) (...) is intent on passing herself off as that individual. On Maher's view, the “Impostor Hypothesis” is the response of a rational agent to the anomalous experience it is invoked to explain. Recently, a number of philosophers have argued that Maher's analysis of delusion doesn't work when applied to the Capgras delusion. In this paper, I defend Maher's analysis against these arguments. However, my aim is not merely to defend Maher's analysis, but also to draw attention to some of the methodological problems that have led to its hasty dismissal. (shrink)

I suggest that we can think of delusional misidentification in terms of systematic errors in the management of mental files. I begin by sketching the orthodox “bottom-up” aetiology of delusional misidentification. I suggest that the orthodox aetiology can be given a descriptivist or a singularist interpretation. I present three cases that a descriptivist interpretation needs to account for. I then introduce a singularist approach, one that is based on mental files, and show how it opens the way for different and (...) potentially more plausible accounts of these three cases. I reflect on how this mental files approach can be viewed either as a supplement to the orthodox aetiology, or as suggesting an altogether different aetiology. I end by addressing a concern surrounding the explanatory power of mental files. (shrink)

In recent times, explanations of the Capgras delusion have tended to emphasise the cognitive dysfunction that is believed to occur at the second stage of two-stage models. This is generally viewed as a response to the inadequacies of the one-stage account. Whilst accepting that some form of cognitive disruption is a necessary part of the aetiology of the Capgras delusion, I nevertheless argue that the emphasis placed on this second-stage is to the detriment of the important role played by the (...) phenomenology underlying the disorder, both in terms of the formation and maintenance of the delusional belief. This paper therefore proposes an interactionist two-stage model in which the phenomenal experience of the Capgras patient is examined, emphasised, and its relation to top-down processing discussed. (shrink)

Anorexia nervosa patients exhibit distorted body-representations. Specifically, they represent their bodies as larger than reality. Given that this distortion likely exacerbates the condition, there is an obligation to further understand and, if possible, rectify it. In pursuit of this, experimental paradigms are needed which manipulate the spatial content of these representations. In this essay, I discuss how virtual reality technology that implements full-body variants of the rubber-hand illusion may prove useful in this regard, and I discuss some issues related to (...) the clinical application of this method. -/- . (shrink)