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)

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 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are misidentified by their subjects as beliefs: the Capgras patient, for instance, does not believe that his wife has been replaced by a robot, instead, he merely imagines that she has, and mistakes this imagining for a belief.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)

This work sets out to present how the notion of delusion may be understood (and extended) within the semantic framework of Robert Brandom's inferentialism. The mechanisms of reliability and community‐oriented proprieties, among others, provide inferentialists with effective tools for understanding commitments (and so beliefs) in communities. These tools may be used to describe and assess both commitments that we might consider sound and commitments that we might consider delusional, both in terms of how they arise and in terms of how (...) they may be reinforced. Delusions are accordingly rendered in perspectival and normative terms, which is elaborated through a number of examples. The picture of how a delusional commitment may be understood, how it may be reinforced, and its character as community internal or external provide some interesting perspectives on delusions in shared social contexts, as well as how they may originate intractable conflicts and disconnects between sub‐groups within a broader linguistic community. (shrink)

This paper explores the possibility of understanding schizophrenic delusion through the role of a primary alteration of subjective experience. Two approaches are contrasted: the first defines schizophrenic delusion as a primary symptom resisting any attempt to understand, whereas the second describes delusion as a secondary symptom, to be understood as a rational reaction of the self. The paper discusses the possibility of applying this second approach to schizophrenic delusion. This leads us to raise the issue of the specificity of psychotic (...) experiences and to wonder whether some accounts of delusion arising in neurological disorders can be generalized into psychotic delusion. A few points are addressed, demanding clarification and the rephrasing of some assumptions implied by the model of a secondary delusion. These points call for an interaction between clinical descriptions, neurocognitive explorations and a philosophical analysis of psychotic subjective experiences. (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)

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)

Clinically significant delusion is a symptom of a number of mental illnesses. We rely on what a person says and how she behaves in order to identify if she has this symptom and it is clear from the literature that delusions are heterogeneous and extremely difficult to define. People with active delusions were interviewed to explore what it is like to develop and experience delusion. The transcribed interview data was analysed to identify themes and narrative trajectories that help to explain (...) the phenomenon. Results showed that delusions can sometimes provide pragmatic benefits and that the genesis of some delusions can be characterised in terms of the enactivist notion of affective framing. Affective framing is a term that captures the background emotions that enable know-how in terms of goal directed action and cognition. If a person’s affective frame alters the world is no longer understood and know-how is lost. The way in which a person relates to her environment can be highly anomalous thus requiring her to find an extraordinary explanation. I argue that delusions arise as a result of a breakdown in affective framing and offer a conceptualisation of delusion supported by empirical findings. (shrink)

Imbalanced plasticity of neural networks in the brain is proposed to underlie deficits in the integration of efferent and afferent processes in schizophrenia. These deficits affect the priming of the behavior implementing systems by prior knowledge, and thus impair both controlled regulation and automatic activation of mental and motor processes. The sense of self as a distinct entity can consequently be undermined. In predominantly reality-distorting patients, hypo-plasticity of neural connectivity may cause the emergence of highly focused but inflexible patterns of (...) activation in their representation and response systems. This may lead to dominance of prepotent patterns of activity in these systems and a relative inability of higher control systems to bias lower level activity towards congruence with the ongoing cognitive and motor context. By contrast, predominantly disorganized patients are characterized by hyper-plastic connectivity. This leads to a weakening of prepotent response tendencies but also, as in reality-distorting patients, to less effective top-down contextual constraining. (shrink)