In this paper we ask whether the two-factor theory of delusions is compatible with two claims, that delusions are pathological and that delusions are adaptive. We concentrate on two recent and influential models of the two-factor theory: the one proposed by Max Coltheart, Peter Menzies and John Sutton (2010) and the one developed by Ryan McKay (2012). The models converge on the nature of Factor 1 but diverge about the nature of Factor 2. The differences between the two models are (...) reflected in different accounts of the pathological and adaptive nature of delusions. We will explore such differences, considering naturalist and normativist accounts of the pathological and focusing on judgements of adaptiveness that are informed by the shear-pin hypothesis (McKay and Dennett 2009). After reaching our conclusions about the two models, we draw more general implications for the status of delusions within two-factor theories. Are there good grounds to claim that delusions are pathological? Are delusions ever adaptive? Can delusions be at the same time pathological and adaptive? (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.

Philosophy and Literature is an internationally renowned refereed journal founded by Denis Dutton at the University of Canterbury, Christchurch. It is now published by the Johns Hopkins University Press. Since its inception in 1976, Philosophy and Literature has been concerned with the relation between literary and philosophical studies, publishing articles on the philosophical interpretation of literature as well as the literary treatment of philosophy. Philosophy and Literature has sometimes been regarded as iconoclastic, in the sense that it repudiates academic pretensions, (...) insidious jargon and institutional vogue. Dutton, who remains the editor, still writes a regular column. A distinctive feature of Philosophy and Literature was the annual Bad Writing Contest, held from 1995–98, which sought to identify (and publish) the ‘most stylistically lamentable passages’ of academic prose, often to great amusement. (shrink)

Monothematic delusions are delusions whose contents pertain to a single subject matter. Examples include Capgras delusion, the delusion that a loved one has been replaced by an impostor, and Cotard delusion, the delusion that one is dead or does not exist. Two-factor accounts of such delusions hold that they are the result of both an experiential deficit, for instance flattened affect, coupled with an aberrant cognitive response to that deficit. In this paper we develop a new expressivist two-factor account of (...) delusion. In contrast to existing endorsement and explanationist accounts, which treat delusions as either explanations or endorsements of the contents of these disordered experiences, we hold that delusional beliefs have an expressive function: they characterize, in impressionistic terms, what the subject’s experience is like for them. We show how our account improves upon existing two-factor views in explaining the central features of monothematic delusions, in particular the way in which delusional subjects fall short of the ideal of rationality. (shrink)

This thesis develops a novel framework for explaining delusions. In Chapter 1, I introduce the two fundamental challenges posed by delusions: the evidence challenge lies in explaining the flagrant ways delusions flout evidence; and the specificity challenge lies in explaining the fact that patients’ delusions are often about a few specific themes, and patients rarely have a wide range of delusional or odd beliefs. In Chapter 2, I discuss the strengths and weaknesses of current theories of delusions, which typically appeal (...) to one or both of two factors: anomalous experience and reasoning abnormality. I argue that anomalous experience can help explain the specificity of delusions, but has difficulties in addressing the evidence challenge; reasoning abnormality can help address the evidence challenge, but has difficulties in explaining the specificity of delusions. This suggests that there may be an important factor that has not been captured by current theories of delusions. To search for this missing factor, in Chapter 3, I turn to normal believing. Inspired by the literature on Cartesian clarity and phenomenal dogmatism, I develop a dual-force framework of believing, according to which beliefs can be understood as the results of the interaction between the justificatory force and causal force of evidence and the justificatory force and causal force of clear experience, in which something clearly seems to be so to the subject. This framework suggests that the missing factor may be the clear experience with its distinctive phenomenal clarity that compels assent. In Chapter 4, I return to delusions, and argue that the dualforce framework can help us to get a better grip on some personal descriptions of delusions; make progress in addressing the evidence and specificity challenges of delusions; and shed new light on the underpinnings of delusions. In the end, I conclude with some remaining questions for future study. (shrink)

Does the formation of delusions involve abnormal reasoning? According to the prominent ‘two-factor’ theory of delusions (e.g. Coltheart, 2007), the answer is yes. The second factor in this theory is supposed to affect a deluded individual's ability to evaluate candidates for belief. However, most published accounts of the two-factor theory have not said much about the nature of this second factor. In an effort to remedy this shortcoming, Coltheart, Menzies and Sutton (2010) recently put forward a Bayesian account of inference (...) in delusions. I outline some criticisms of this important account, and sketch an alternative account of delusional inference that, I argue, avoids these criticisms. Specifically, I argue that the second factor in delusion formation involves a systematic deviation from Bayesian updating, a deviation that may be characterized as a bias towards ‘explanatory adequacy’. I present a numerical model of this idea and show that my alternative account is broadly consistent with prominent prediction error models of delusion formation (e.g. Corlett, Murray et al., 2007). (shrink)

Stanford Encyclopedia Entry on Delusions.

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)

When laws or legal principles mention mental states such as intentions to form a contract, knowledge of risk, or purposely causing a death, what parts of the brain are they speaking about? We argue here that these principles are tacitly directed at our prefrontal executive processes. Our current best theories of consciousness portray it as a workspace in which executive processes operate, but what is important to the law is what is done with the workspace content rather than the content (...) itself. This makes executive processes more important to the law than consciousness, since they are responsible for channeling conscious decision-making into intentions and actions, or inhibiting action.We provide a summary of the current state of our knowledge about executive processes, which consists primarily of information about which portions of the prefrontal lobes perform which executive processes. Then we describe several examples in which legal principles can be understood as tacitly singling out executive processes, including principles regarding defendants’ intentions or plans to commit crimes and their awareness that certain facts are the case, as well as excusatory principles which result in lesser responsibility for those who are juveniles, mentally ill, sleepwalking, hypnotized, or who suffer from psychopathy. (shrink)

Delusions are usually depicted in one of two contrasting ways. They are either characterized as harmful and dysfunctional beliefs or as fostering engagement with the environment and sometimes even psychological wellbeing in the face of psychological or biological difficulties – something which, according to some accounts, would make them biologically adaptive. It is this “adaptive hypothesis” that I focus on in this paper, by empirically investigating the adaptiveness of delusions in a sample of people suffering from OCD. The paper shows (...) that delusions in OCD entertain complex and heterogeneous relationships with psychological wellbeing and engagement with the environment, highlighting some future directions that clinical and philosophical research on the topic should take. (shrink)

This paper contrasts an interactionist account of delusional misidentification with more traditional one- and two-stage models. Unlike the unidirectional nature of these more traditional models, in which the aetiology of the disorder is said to progress from a neurological disruption via an anomalous experience to a delusional belief, the interactionist account posits the interaction of top-down and bottom-up processes to better explain the maintenance of the delusional belief. In addition, it places a greater emphasis on the patient’s underlying phenomenal experience (...) in accounting for the specificity of the delusional content. The role played by patient phenomenology is examined in light of Ratcliffe’s recent phenomenological account. Similarities and differences are discussed. The paper concludes that a purely phenomenological account is unable to differentiate between non-delusional patient groups, who have what appear to be equivalent phenomenal experiences to patients suffering from delusional misidentification but without the delusional belief, and delusional groups, something the interactionist model is able to do. (shrink)

A recent debate in the literature on delusions centers on the question of whether delusions are beliefs or not. In this paper, an overlooked distinction between egocentric and encyclopedic doxastic states is introduced and brought to bear on this debate, in particular with regard to delusions of misidentification. The result is that a more accurate characterization of the delusional subject’s doxastic point of view is made available. The patient has a genuine egocentric belief (“This man is not my father”), but (...) fails to have the commonly attributed encyclopedic belief (“My father has been replaced by an impostor”). (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)

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)

The comparator-model, originally developed to explain motor action, has recently been invoked to explain several aspects of the self. However, in the first place it may not be used to explain a basic self-world distinction because it presupposes one. Our alternative account is based on specific systematic covariation between action and perception. Secondly, the comparator model cannot explain the feeling of ownership of thoughts. We argue—contra Frith and Campbell—that thoughts are not motor processes and therefore cannot be described by the (...) comparator-model. Rather, thoughts can be the triggering cause (intention) for actions. An alternative framework for the explanation of thought insertion in schizophrenics is presented. (shrink)

The ‘mineness’ of thoughts has often been accepted as indubitable in philosophy. However, the symptom of thought insertion in schizophrenia seems to be an empirical counterexample to the dictum that every introspected thought is one's own. We present a thorough conceptual analysis of mineness of thought, distinguishing between ownership and authorship . We argue that it is indeed a conceptual truth that introspected thoughts are owned by the introspector. However, there are everyday and pathological cases of thoughts, for which we (...) do not ascribe authorship to ourselves. To explain inserted thoughts, however, we need an additional factor which is constituted by the lack of control over inserted thoughts . We present a review of empirical data on thought control and thought insertion in the light of the conceptual analysis. We conclude with a summary of the most important future direction of research. (shrink)

En el presente artículo me concentraré en el estudio filosófico de los delirios, como un caso ejemplificador del vínculo que pueden establecer la filosofía de la mente y la psiquiatría. Frente a versiones radicalmente naturalistas, que proponen variantes reduccionistas o eliminativistas para la explicación de ciertos fenómenos mentales y sus variantes “anormales”, defenderé una versión moderada de la perspectiva naturalista. Al respecto, señalaré que retener algún grado de simpatía hacia el naturalismo en las investigaciones filosóficas sobre los delirios es necesario (...) para desarrollar teorías sobre las creencias empíricamente informadas que no resulten contradictorias con los desarrollos actuales en psicología cognitiva y neurociencias. No obstante, afirmaré también que una perspectiva exclusivamente naturalista -tanto por parte de la filosofía como de la psiquiatría misma- es incapaz de dar cuenta del contexto normativo en donde juegan las creencias. Los criterios normativos, especialmente externos que se emplean para clasificar ciertas creencias como delirantes no resultan inteligibles bajo una explicación puramente natural. Por el contrario, para comprender las creencias delirantes qua delirantes, será preciso acercarnos a un abordaje híbrido que pueda contemplar las causas naturales del fenómeno así como su evaluación normativa. (shrink)

Bortolotti argues that we cannot distinguish delusions from other irrational beliefs in virtue of their epistemic features alone. Although her arguments are convincing, her analysis leaves an important question unanswered: What makes delusions pathological? In this paper I set out to answer this question by arguing that the pathological character of delusions arises from an executive dysfunction in a subject’s ability to detect relevance in the environment. I further suggest that this dysfunction derives from an underlying emotional imbalance—one that leads (...) delusional subjects to regard some contextual elements as deeply puzzling or highly significant. (shrink)

The sense of embodiment is vital for self recognition. An examination of anosognosia for hemiplegia—the inability to recognise that one is paralysed down one side of one’s body—suggests the existence of ‘online’ and ‘offline’ representations of the body. Online representations of the body are representations of the body as it is currently, are newly constructed moment by moment and are directly “plugged into” current perception of the body. In contrast, offline representations of the body are representations of what the body (...) is usually like, are relatively stable and are constructed from online representations. This distinction is supported by an analysis of phantom limb—the feeling that an amputated limb is still present—phenomena. Initially it seems that the sense of embodiment may arise from either of these types of representation; however, an integrated representation of the body seems to be required. It is suggested information from vision and emotions is involved in generating these representations. A lack of access to online representations of the body does not necessarily lead to a loss in the sense of embodiment. An integrated offline representation of the body could account for the sense of embodiment and perform the functions attributed to this sense. (shrink)

There is an increasing amount of empirical work investigating the sense of agency, i.e. the registration that we are the initiators of our own actions. Many studies try to relate the sense of agency to an internal feed-forward mechanism, called the ‘‘comparator model’’. In this paper, we draw a sharp distinction between a non-conceptual level of feeling of agency and a conceptual level of judgement of agency. By analyzing recent empirical studies, we show that the comparator model is not able (...) to explain either. Rather, we argue for a two-step account: a multifactorial weighting process of different agency indicators accounts for the feeling of agency, which is, in a second step, further processed by conceptual modules to form an attribution judgement. This new framework is then applied to disruptions of agency in schizophrenia, for which the comparator model also fails. Two further extensions are discussed: We show that the comparator model can neither be extended to account for the sense of ownership (which also has to be differentiated into a feeling and a judgement of ownership) nor for the sense of agency for thoughts. Our framework, however, is able to provide a unified account for the sense of agency for both actions and thoughts. (shrink)

The neurocognitive structure of the acting self has recently been widely studied, yet is still perplexing and remains an often confounded issue in cognitive neuroscience, psychopathology and philosophy. We provide a new systematic account of two of its main features, the sense of agency and the sense of ownership, demonstrating that although both features appear as phenomenally uniform, they each in fact are complex crossmodal phenomena of largely heterogeneous functional and representational levels. These levels can be arranged within a gradually (...) evolving, onto- and phylogenetically plausible framework which proceeds from basic non-conceptual sensorimotor processes to more complex conceptual and meta-representational processes of agency and ownership, respectively. In particular, three fundamental levels of agency and ownership processing have to be distinguished: The level of feeling, thinking and social interaction. This naturalistic account will not only allow to “ground the self in action”, but also provide an empirically testable taxonomy for cognitive neuroscience and a new tool for disentangling agency and ownership disturbances in psychopathology. (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)

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)

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)

Les délires sont des composantes cruciales de nombreux troubles psychiques, surtout la schizophrénie. Que sont les délires? Selon l’opinion courante, il s’agit d’un type de croyance, plus précisément, une croyance pathologique. Malheureusement, l’opinion courante ne correspond pas rigoureusement, dans tous les cas, à la pratique clinique, où l’expression « délire » est souvent appliquée à des états qui ne sont pas des croyances. Nous examinons les raisons pour lesquelles des états qui ne sont pas des croyances peuvent être considérés comme (...) des délires. Nous soutenons que les délires sont des structures complexes d’attitudes d’ordre supérieur et inférieur. Ils constituent un type spécifique de défaillance de la connaissance et de la gestion de soi. Nous fournirons une description du type en question. Notre point de vue implique sur le plan conceptuel que les croyances ne sont pas essentielles aux délires.Delusions are critical components in a number of mental disorders, schizophrenia formost. What are they? The standard view is that they are a type of belief — a pathological belief. Unfortunately, the standard view does not consistently correspond to clinical practice, where the term « delusion » often applies to non-beliefs. We review the case for saying that non-beliefs can count as delusions. We argue that delusions are complexes of higher and lower order attitudes. They constitute a distinctive type of failure of self-knowledge and self-management. We describe the relevant type. One of the conceptual implications of our view is that beliefs need not be central to delusions. (shrink)

Experiences of thought-insertion are a first-rank, diagnostically central symptom of schizophrenia. Schizophrenic patients who undergo such delusional mental states report being first-personally aware of an occurrent conscious thought which is not theirs, but which belongs to an external cognitive agent. Patients seem to be right about what they are thinking but mistaken about who is doing the thinking. It is notoriously difficult to make sense of such delusions. One general approach to explaining the etiology of monothematic delusions has come to (...) be known as the endorsement model. This model claims that the patient holds her delusional belief because she simply trusts her bizarre experience and takes it at face value. The content of the bizarre experience thus plays a central role in the etiology of delusions. Despite being widely discussed with respect to delusions like Capgras and Cotard, an endorsement model of thought-insertion has not yet been formulated. This article seeks to fill this void by fleshing out and defending the endorsement approach to delusions of inserted thoughts. It aims to show that such an approach can be defended against objections that have been raised in the literature. In particular, it will be argued that there is nothing wrong with the idea of being first-personally aware of a thought which is presented in consciousness as being someone else's. The upshot is that with respect to delusions of thought-insertion, the endorsement model turns out to be a viable account of why patients come to believe that someone else is inserting thoughts into their minds. (shrink)

The aim of this article is to analyze those theories that interpret misidentification delusions in terms of mentalization. The hypothesis under examination holds that a mentalization framework is useful for describing misidentification delusions when identification is thought to be partially based on mentalization. The article provides both a characterization and possible interpretations of such delusions, and possible relations between misidentification and mentalization are scrutinized. Whether the mentalization approach may explain or describe such kinds of mental disorders is considered, with the (...) conclusion that while this approach is unsatisfactory, there is some room for future improvement. (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)

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)

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)

Although the sense of agency is often reduced if not absent in dreams, our agentive dream experiences can at times be similar to or enhanced compared to waking. The sense of agency displayed in dreams is perplexing as we are mostly shut off from real stimulus whilst asleep. Theories of waking sense of agency, in particular, comparator and holistic models, are analysed in order to argue that despite the isolation from the real environment, these models can help account for dream (...) experience. The dreamer might feel an increased sense of control of their dream bodies and a sense that they can directly control elements of the dream world. Such experiences may at times be caused by superstitious or delusional thinking due to altered cognition and changes to the sleeping brain. Here it is argued that some such experiences are akin to specific waking delusions, such as delusions of grandeur, with similar cognitive features. However, other instances of increased sense of agency in dreaming appear to be sui generis and nothing like what we experience when awake. Lucid control dreams, in which the dreamer realises that they are dreaming and that they can control the dream environment, are examples of such an experience although further nuance is required to account for their specific cognitive attributes. Future empirical research should focus on controlled dream reporting conditions in order to clarify the types of experience that occur and determine the relevant cognitive mechanisms that relate to each type. (shrink)

Our eyes, bodies, and perspectives are constantly shifting as we observe the world. Despite this, we are very good at distinguishing between self-caused visual changes and changes in the environment: the world appears mostly stable despite our visual field moving around. This, it seems, also occurs when we are dreaming. As we visually investigate the dream environment, we track moving objects with our dream eyes, examine objects, and shift focus. These movements, research suggests, are reflected in the rapid movements or (...) saccades of our sleeping eyes. Do we really see the dream world in the same way that we see the real world? If we do, how could dreaming, usually assumed to be mind-generated hallucinations, replicate such an experience? This problem would be deflated if dreams are not hallucinations at all, but rather imagination, illusion or simply unrealistic. I argue that imagination and illusion views do not satisfactorily explain away the problem of vision and action in sleep. The imagination model is not a complete description of dreaming that is consistent with empirical research, and it is unlikely that the visual dream world is an illusion. Given that the dreaming visual experience is most likely active, hallucinatory, and at times a realistic world simulation, there are important implications for our understanding of visual perception and its relationship to movement. Evidence suggests that our dream eyes investigate the dream world as our waking eyes investigate the waking world. If changes to the unconsciously generated dream environment are perceived as external and unintentional while dream body movements are perceived as self-generated and intentional, current theory of visual perception may have to be expanded to account for how the dreaming mind generates a stable world in which we track and visually explore mind-generated objects. (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)

This paper draws on studies of the Capgras delusion in order to illuminate the phenomenological role of affect in interpersonal recognition. People with this delusion maintain that familiars, such as spouses, have been replaced by impostors. It is generally agreed that the delusion involves an anomalous experience, arising due to loss of affect. However, quite what this experience consists of remains unclear. I argue that recent accounts of the Capgras delusion incorporate an impoverished conception of experience, which fails to accommodate (...) the role played by ‘affective relatedness’ in constituting (a) a sense of who a particular person is and (b) a sense of others as people rather than impersonal objects. I draw on the phenomenological concept of horizon to offer an interpretation of the Capgras experience that shows how the content ‘this entity is not my spouse but an impostor’ can be part of the experience, rather than something that is inferred from a strange experience. (shrink)

This paper explores the two-factor theoretical model currently widely used to provide an explanatory analysis of the delusions that regularly accompany neurological disease or damage. The model hypothesizes a combination of an experiential factor – a strange or untoward experience – and a cognitive factor, such as an impairment of reasoning. The two-factor model has been devised formonothematicdelusions that are usually manifested in a single, implausible idea. These have to be distinguished from the more elaborated,polythematicdelusions that are found in psychiatry. (...) Psychiatric delusions exceed neurological ones in frequency and, often, semantic complexity. This text offers a preliminary clarification of underlying assumptions about the breadth, terminology and presuppositions of two-factor theorizing, exploring its potential application to psychiatric delusions. (shrink)

My aim in this paper is to consider the question ‘Why is belief in God not a delusion?’. In the first half of the paper, I distinguish two kinds of religious belief: institutional and personal religious belief. I then review how cognitive science accounts for cultural processes in the acquisition and transmission of institutional religious beliefs. In the second half of the paper, I present the clinical definition of delusion and underline the fact that it exempts cultural beliefs from clinical (...) diagnosis. Finally, I review cognitive models of the intuitive attribution of mental disorders and how they support cultural exemption. Through the comparison of the models of cultural acquisition of religious beliefs and of cultural exemption in the attribution of delusion I intend to make it clear that we can provide an answer to our motivating question: even though some institutional religious beliefs may seem as strange as the most florid delusions, humans can readily recognize that they are not the product of mental dysfunction due to the fact that their acquisition and transmission is embedded within a cultural context. (shrink)

Clinical delusions have traditionally been characterized as beliefs in psychiatry. However, philosophers have recently engaged with the empirical literature and produced a number of objections to the so-called doxastic status of delusion, stemming mainly from the mismatch between the functional role of delusions and that expected of beliefs. In response to this, an appeal to dispositionalism about the nature of belief has been proposed to vindicate the doxastic status of delusion. In this paper, I first present the objections to attributing (...) beliefs to delusional patients and the application of dispositionalism in the attempt to vindicate doxasticism. I then assess this application and some responses to the objections to the doxastic characterization. Finally, I offer some conclusions about the limits of folk-psychological concepts in the characterization and explanation of complex psychological phenomena such as delusions. (shrink)

Much attention has been paid recently to the role of anomalous experiences in the aetiology of certain types of psychopathology, e.g. in the formation of delusions. We examine, instead, the top-down influence of pre-existing beliefs and affective factors in shaping an individual’s characterisation of anomalous sensory experiences. Specifically we investigated the effects of paranormal beliefs and alexithymia in determining the intensity and quality of an altered state of consciousness . Fifty five participants took part in a sweat lodge ceremony, a (...) traditional shamanic ritual which was unfamiliar to them. Participants reported significant alterations in their state of consciousness, quantified using the ‘APZ’ questionnaire, a standardized measure of ASC experience. Participants endorsing paranormal beliefs compatible with shamanic mythology, and those showing difficulty identifying feelings scored higher on positive dimensions of ASC experience. Our findings demonstrate that variation in an individual’s characterisation of anomalous experiences is nuanced by pre-existing beliefs and affective factors. (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)

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)

The Capgras delusion is a condition in which a person believes that an imposter has replaced some close friend or relative. Recent theorists have appealed to Bayesianism to help explain both why a subject with the Capgras delusion adopts this delusional belief and why it persists despite counter-evidence. The Bayesian approach is useful for addressing these questions; however, the main proposal of this essay is that Capgras subjects also have a delusional conception of epistemic possibility, more specifically, they think more (...) things are possible, given what is known, than non-delusional subjects do. I argue that this is a central way in which their thinking departs from ordinary cognition and that it cannot be characterized in Bayesian terms. Thus, in order to fully understand the cognitive processing involved in the Capgras delusion, we must move beyond Bayesianism. 1 The Simple Bayesian Model2 Anomalous Evidence and the Capgras Delusion3 Impaired Reasoning4 Setting Priors5 Epistemic Modality6 Delusions of Possibility7 Delusions of Possibility in Different Contexts8 How Many Factors? (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)

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)

What exactly do we do when we try to make sense of other people e.g. by ascribing mental states like beliefs and desires to them? After a short criticism of Theory-Theory, Interaction Theory and the Narrative Theory of understanding others as well as an extended criticism of the Simulation Theory in Goldman's recent version (2006), we suggest an alternative approach: the Person Model Theory . Person models are the basis for our ability to register and evaluate persons having mental as (...) well as physical properties. We argue that there are two kinds of person models, nonconceptual person schemata and conceptual person images , and both types of models can be developed for individuals as well as for groups. (shrink)

The central hypothesis of this book, Delusions and Beliefs: A Philosophical Inquiry (Routledge, 2019), is that delusions are malfunctional beliefs (Chapter 1); they belong to the category of belief (Chapter 2) but, unlike mundane false or irrational beliefs, they fail to perform some functions of belief (Chapter 3). More precisely, delusions directly or indirectly involve some malfunctioning cognitive mechanisms, which is empirically supported by the two-factor account of delusion formation (Chapter 4).

Reflection on skeptical scenarios in the philosophy of perception, made vivid in the arguments from illusion and hallucination, have led to the formulation of theories of the metaphysical and epistemological nature of perceptual experience. In recent times, the locus of the debate concerning the nature of perceptual experience has been the dispute between disjunctivists and common-kind theorists. Disjunctivists have held that there are substantial dissimilarities (either metaphysical or epistemological or both) between veridical perceptual experiences occurring when one perceives and perceptual (...) experiences involved in hallucination. Common-kind theorists have denied this. In this paper, I examine the nature of introspection – a faculty that has often been compared and contrasted to perception. I reflect on cases where introspection goes wrong in ways analogous to that in which our perceptual faculties can go wrong and formulate, what I take to be, an attractive theory of introspection. The cases that I focus on in which things go wrong are the case of zombies and the case of subjects with Anton’s syndrome. (Anton’s syndrome is a condition in which people who are blind claim that they can see.) I suggest that, just as it is possible to be a disjunctivist about perception, it is possible to be a disjunctivist about introspection. I argue that this is a good view of one type of introspection, namely, introspection of states that have phenomenal character, such as perceptual experiences. It has a good account to give of the cases in which such introspection seems to go wrong and it yields a plausible metaphysical and epistemological view of the nature of introspection. However, while I favour a disjunctive view of introspection, I do not favour a disjunctive view of perception. And, I suspect, that many disjunctivists about perception would not wish to condone my disjunctivist theory of introspection. I therefore go on to examine to what extent.. (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)

El problema tipológico surge al intentar definir el tipo de estado mental que subyace a los reportes de pacientes delirantes. Este artículo explora dos de los enfoques más populares a este problema en la literatura actual en filosofía de la mente. El análisis concluye que el enfoque doxástico —que conceptualiza los delirios como creencias anormales— es superior en términos conceptuales, empíricos y fenomenológicos al enfoque imaginístico, que caracteriza a los delirios como un tipo de estado mental imaginario. Finalmente, se concluye (...) con algunos de los desafíos que el enfoque necesita resolver para ampliar su alcance y poder explicativo. (shrink)

Addiction is almost universally held to be characterized by a loss of control over drug-seeking and consuming behavior. But the actions of addicts, even of those who seem to want to abstain from drugs, seem to be guided by reasons. In this paper, I argue that we can explain this fact, consistent with continuing to maintain that addiction involves a loss of control, by understanding addiction as involving an oscillation between conflicting judgments. I argue that the dysfunction of the mesolimbic (...) dopamine system that typifies addictions causes the generation of a mismatch between the top-down model of the world that reflects the judgment that the addict ought to refrain from drugs, and bottom-up input caused by cues predictive of drug availability. This constitutes a powerful pressure toward revising the judgment and thereby attenuating the prediction error. But the new model is not stable, and shifts under the pressure of bottom-up inputs in different contexts; hence the oscillation of all-things-considered judgment. Evidence from social psychology is adduced, to suggest that a similar process may be involved in ordinary cases of weakness of will. (shrink)