Stanford Encyclopedia Entry on Delusions.

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)

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)

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)

Italy is in the forefront of forensic neuroscience practice among European nations. In recent years, the country presented two major criminal cases, the Trieste Case in 2009 and the Como Case in 2011, which were the first cases employing neurogenetic and functional neuroimaging methods in European courts. In this paper we will discuss the consequences that an understanding of the neural and genetic determinants of human (mis)behavior will have on law, especially on the Italian legal context. Some claim that such (...) consequences will actually be revolutionary, while others argue that legal doctrine assumptions won’t be undermined by neuroscientific findings. In the first section of the paper, we introduce the general debate and follow with a section devoted to the two Italian cases. In the third and final section, we discuss epistemological and ethical issues regarding Italian neurolaw. We defend a position which diverges from those prevailing in the debate. While negative outcomes and concerns were usually evidenced, we focus on positive changes coming with the new paradigm of interaction between neuroscience and the law. Our view is that these cases are clearly pioneering ones, anticipating what will happen in the courtrooms of the European Union in the whole, in the near future. (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)

Philosophical Psychology, Volume 25, Issue 4, Page 617-621, August 2012.

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)

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)

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)

What is the relationship between the concepts of the predictive processing theory of brain functioning and the everyday concepts with which people conduct and explain their mental lives? To answer this question, we focus on predictive processing explanations of mental disorder that appeal to false inference. After distinguishing two concepts of false inference, we survey four ways of understanding the relationship between explanations of mental phenomena at the personal and sub-personal level. We then argue that if predictive processing accurately accounts (...) for psychological and socio-cultural dynamics, then personal and sub-personal concepts must display a looping relationship that can impact the nature of at least some mental phenomena. In particular, explaining the phenomenon of delusion in terms of the sub-personal concept of false inference should change the nature of delusional experiences themselves. (shrink)

The paper attempts to pose a problem for theories claiming that intentional attributions are essentially normative. Firstly, I argue that the claim is ambiguous. Secondly, that three possible interpretations of the claim can be distinguished: one that appeals to normative impositions put on agents of intentional states, another that exploits the fact that one can normatively assess the states in question and a further one that locates normativity in the domain of special intentional explanations. Thirdly, it is argued that each (...) interpretation faces serious difficulties: they either fail to provide a justification for the claim they intend to make or they contradict certain justified observations about intentional attributions. (shrink)

The idea that mental illnesses are impairments in rationality is very old, and very common (Kasanin 1944; Harvey et al. 2004; Graham 2010). But is it true? In this article two severe mental disorders, schizophrenia and delusional disorder, are investigated in order to find some defects in rationality. Through the analysis of patients’ performances on different tests, and the investigation of their typical reasoning styles, I will show that mental disorders can be deficits in social cognition, or common sense, but (...) not in rationality (Sass 1992; Johnson-Laird et al. 2006; Bergamin 2018). Moreover, my claim is that psychopathological patients can also be, in some circumstances, more logical than normal controls (Kemp et al. 1997; Owen et al. 2007). From a philosophical point of view these data seem to be very relevant, because they help us to reconsider our idea of rationality, and to challenge the common way to look at sanity and mental illness. (shrink)

Philosophers have been long interested in delusional beliefs and in whether, by reporting and endorsing such beliefs, deluded subjects violate norms of rationality (Campbell 1999; Davies & Coltheart 2002; Gerrans 2001; Stone & Young 1997; Broome 2004; Bortolotti 2005). So far they have focused on identifying the relation between intentionality and rationality in order to gain a better understanding of both ordinary and delusional beliefs. In this paper Matthew Broome and I aim at drawing attention to the extent to which (...) deluded subjects are committed to the content of their delusional beliefs, that is, to whether they can be regarded as authors of their beliefs (Moran 2001). We consider several levels of commitment one can have to a reported belief, delusional or otherwise, and we distinguish between _ownership_ and _authorship_ of beliefs (Gallagher 2000). After examining some examples of belief authoring (or lack thereof) in psychopathology, we argue that there is no straight-forward and unitary answer to the question whether deluded subjects author their beliefs. Nevertheless, introducing the notion of authorship in the debate can significantly contribute to the philosophical literature on the rationality of delusions and can also have important implications for diagnosis and therapy in psychiatry. (shrink)

Descartes was certain that he was thinking and he was accordingly certain that he existed. Like Descartes, we seem to be more certain of our thoughts and our existence than of anything else. What is less clear is the reason why we are thus certain. Philosophers throughout history have provided different interpretations of the cogito, disagreeing both on the kind of thoughts it characterizes and on the reasons for its cogency. According to what we may call the empiricist interpretation of (...) the cogito, I can only claim to be certain of having experiences, and this certainty, as well as that of my own existence, stems from their phenomenal and subjective character. According to rationalist interpretations, on the other hand, I am certain of having some self-reflexive propositional attitudes, and this certainty derives from their rational features. Psychiatric patients suffering from acute forms of depersonalization or of the Cotard syndrome often doubt that they think and exist, and might even believe that they don't. I argue that their study allows us to favor the empiricist interpretation of the cogito. (shrink)

Patients suffering from the Cotard syndrome can deny being alive, having guts, thinking or even existing. They can also complain that the world or time have ceased to exist. In this article, I argue that even though the leading neurocognitive accounts have difficulties meeting that task, we should, and we can, make sense of these bizarre delusions. To that effect, I draw on the close connection between the Cotard syndrome and a more common condition known as depersonalisation. Even though they (...) are not delusional, depersonalised patients seem to have experiences that are quite similar to those of Cotard patients. I argue that these experiences are essentially characterised by a lack of subjective character and of two other structural features of experience, which I call ‘the present character’ and ‘the actual character’. Cotard's nihilistic delusions simply consist in taking these anomalous experiences at face value. (shrink)

Basic self-awareness is the kind of self-awareness reflected in our standard use of the first-person. Patients suffering from severe forms of depersonalization often feel reluctant to use the first-person and can even, in delusional cases, avoid it altogether, systematically referring to themselves in the third-person. Even though it has been neglected since then, depersonalization has been extensively studied, more than a century ago, and used as probe for understanding the nature and the causal mechanisms of basic self-awareness. In this paper, (...) I argue that depersonalized patients indeed have an impaired basic self-awareness, and that their study allows us both to favor one specific theory of basic self-awareness and to understand what is wrong with its rivals. According to the favored theory, which I call Cartesian, we are basically self-aware in virtue of being acquainted with ourselves through introspection. (shrink)

Basic self-awareness is the kind of self-awareness reflected in our standard use of the first-person. Patients suffering from severe forms of depersonalization often feel reluctant to use the first-person and can even, in delusional cases, avoid it altogether, systematically referring to themselves in the third-person. Even though it has been neglected since then, depersonalization has been extensively studied, more than a century ago, and used as probe for understanding the nature and the causal mechanisms of basic self-awareness. In this paper, (...) I argue that depersonalized patients indeed have an impaired basic self-awareness, and that their study allows us both to favor one specific theory of basic self-awareness and to understand what is wrong with its rivals. According to the favored theory, which I call Cartesian, we are basically self-aware in virtue of being acquainted with ourselves through introspection. (shrink)

Debates about bodily ownership and psychological ownership have typically proceeded independently of each other. This paper explores the relation between them, with particular reference to how each is illuminated by psychopathology. I propose a general framework for studying ownership that is applicable both to bodily ownership and psychological ownership. The framework proposes studying ownership by starting with explicit judgments of ownership and then exploring the bases for those judgments. Section 3 discusses John Campbell’s account of ψ-ownership in the light of (...) that general framework, emphasizing in particular his fractionation of ψ-ownership into two dissociable components. Section 4 briefly presents an account of φ-ownership that I have developed in more detail elsewhere. Section 5 explores the suggestion, originating with Alexandre Billon, that there needs to be an integrated account of φ-ownership and ψ-ownership because depersonalization disorders typically involve breakdowns of both φ-ownership and ψ-ownership. The argument from depersonalization is not compelling, but Section 6 proposes a different way of reaching the same conclusion. Section 7 shows how reflecting on agency and practical reasoning offers a common thread between the models of φ-ownership and ψ-ownership discussed earlier in the paper. (shrink)

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)

If I see, hear, or touch a sparrow, the sparrow seems real to me. Unlike Bigfoot or Santa Claus, it seems to exist; I will therefore judge that it does indeed exist. The “sense of existence” refers to the kind of awareness that typically grounds such ordinary judgments of existence or “reality.” The sense of existence has been invoked by Humeans, Kantians, Ideologists, and the phenomenological tradition to make substantial philosophical claims. However, it is extremely controversial; its very existence has (...) been called into question. This paper aims to clarify the nature and reality of the sense of existence by studying a psychiatric condition in which the sense appears to be disrupted: depersonalization disorder (DPD). (shrink)

The paper discusses the role affective factors may play in explaining why, in Capgras'delusion, the delusional belief once formed is maintained and argues that there is an important link between the modularity of the relevant emotional system and the persistence of the delusional belief.

Clinical delusions are widely characterized as being pathological beliefs in both the clinical literature and in common sense. Recently, a philosophical debate has emerged between defenders of the commonsense position (doxasticists) and their opponents, who have the burden of pointing toward alternative characterizations (anti-doxasticists). In this chapter, I argue that both doxasticism and anti- doxasticism fail to characterize the functional role of delusions while at the same time being unable to play a role in the explanation of these phenomena. I (...) also argue that though a more nuanced view of belief in which mental states are more or less belief-like instills a healthy skepticism towards the precision of folk-psychological concepts, such a stance fails to be of use in building a theory of delusion that will be able to bridge different levels of explanation, such as the phenomenology and neurobiology of delusion. Thus, I advocate moving past the question ‘Are delusions beliefs?’ and their description as propositional attitudes toward the description of the processes that generate delusion, with a view toward explaining, rather than explaining away, the personal-level aspects of the phenomenon that have been made inscrutable by investing in doxastic terminology. (shrink)