Folie à deux is the transference of delusional ideas from one 'primary' individual to one or more 'secondary' individuals (Lasègue & Falret, 1877). However, it is difficult to investigate experimentally because often only one patient is identified as delusional. We investigated whether hypnosis could model the experiences of the secondary in this delusion. Our primary was a confederate, who displayed two delusional beliefs and attempted to transmit them to hypnotised subjects. We manipulated the status of the confederate so that they (...) were portrayed as either "credible" or merely "interesting". Many high hypnotisable individuals adopted the confederate's beliefs and confabulated evidence in support of them. Also, subjects who interacted with a credible confederate extended their delusions beyond those displayed by the confederate. We discuss the strengths and limitations of this approach and suggest ways to improve the validity of this model. (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)

How do I know that I am the person who is moving? According to Wittgenstein (1958), the sense of agency involves a primitive notion of the self used as subject, which does not rely on any prior perceptual identification and which is immune to error through misidentification. However, the neuroscience of action and the neuropsychology of schizophrenia show the existence of specific cognitive processes underlying the sense of agency—the ‘‘Who'' system (Georgieff & Jeannerod, 1998) which is disrupted in delusions of (...) control (Frith, 1992). Yet, we have to be careful in the interpretation of such clinical symptoms, which cannot be so easily reduced to deficit of action monitoring or to lack of action awareness. Moreover, we should refine the definition of the sense of agency by distinguishing the sense of initiation and the sense of one's own movements. A conceptual analysis of the empirical data will lead us to establish the taxonomy of the different levels of action representations. (shrink)

There are two main pathways to investigate the sense of body ownership, (i) through the study of the conditions of embodiment for an object to be experienced as one's own and (ii) through the analysis of the deficits in patients who experience a body part as alien. Here, I propose that E is embodied if some properties of E are processed in the same way as the properties of one's body. However, one must distinguish among different types of embodiment, and (...) only self-specific embodiment can lead to feelings of ownership. I address issues such as the functional role and the dynamics of embodiment, degrees and measures of ownership, and shared body representations between self and others. I then analyse the interaction between ownership and disownership. On the one hand, I show that there is no evidence that in the Rubber Hand Illusion, the rubber hand replaces the biological hand. On the other hand, I argue that the sense of disownership experienced by patients towards their body part cannot be reduced to the mere lack of ownership. (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.

The present paper investigated the nature and structure of extra-terrestrial beliefs. Respondents completed a booklet containing items measuring belief in extra-terrestrial life, alien visitation, and paranormal belief (Revised Paranormal Belief Scale, R-PBS; and the Australian Sheep Goat Scale, ASGS). Responses were analyzed using principal component analysis (PCA), and a three-factor structure emerged: alien visitation, belief in extra-terrestrial life, and the search for extra-terrestrials. Further analysis revealed that males scored higher than females on belief in extra-terrestrial life and the search for (...) extra-terrestrial life. No difference was observed for alien visitation. Correlational analysis found significant positive associations between each of the extra-terrestrial life factors and alien visitation. In addition to this, the extra-terrestrial life factors and alien visitation were found to correlate with overall paranormal belief (ASGS), and the two factors of the R-PBS (Traditional Paranormal Belief and New Age Philosophy). Alien Visitation was more strongly correlated with the paranormal belief measures than the extra-terrestrial belief factors; these were found to be negatively correlated with the paranormal belief measures when Alien Visitation was controlled for. These findings indicate that only more extreme Alien Visitation beliefs were associated with belief in the paranormal. Keywords: alien visitation—belief in extra-terrestrial life—search for extra-terrestrial life—paranormal belief. (shrink)

We show how an epistemology informed by cognitive science promises to shed light on an ancient problem in the philosophy of mathematics: the problem of exactness. The problem of exactness arises because geometrical knowledge is thought to concern perfect geometrical forms, whereas the embodiment of such forms in the natural world may be imperfect. There thus arises an apparent mismatch between mathematical concepts and physical reality. We propose that the problem can be solved by emphasizing the ways in which the (...) brain can transform and organize its perceptual intake. It is not necessary for a geometrical form to be perfectly instantiated in order for perception of such a form to be the basis of a geometrical concept. (shrink)

This thesis investigates the relationship between consciousness and self-consciousness. I consider two broad claims about this relationship: a constitutive claim, according to which all conscious experiences constitutively involve self-consciousness; and a typicalist claim, according to which ordinary conscious experiences contingently involve self-consciousness. Both of these claims call for elucidation of the relevant notions of consciousness and self-consciousness. -/- In the first part of the thesis ('The Myth of Constitutive Self-Consciousness'), I critically examine the constitutive claim. I start by offering an (...) elucidatory account of consciousness, and outlining a number of foundational claims that plausibly follow from it. I subsequently distinguish between two concepts of self-consciousness: consciousness of one's experience, and consciousness of oneself (as oneself). Each of these concepts yields a distinct variant of the constitutive claim. In turn, each resulting variant of the constitutive claim can be interpreted in two ways: on a 'minimal' or deflationary reading, they fall within the scope of foundational claims about consciousness, while on a 'strong' or inflationary reading, they point to determinate aspects of phenomenology that are not acknowledged by the foundational claims as being aspects of all conscious mental states. I argue that the deflationary readings of either variant of the constitutive claim are plausible and illuminating, but would ideally be formulated without using a term as polysemous as 'self-consciousness'; by contrast, the inflationary readings of either variant are not adequately supported. -/- In the second part of the thesis ('Self-Consciousness in the Real World'), I focus on the second concept of self-consciousness, or consciousness of oneself as oneself. Drawing upon empirical evidence, I defend a pluralist account of self-consciousness so construed, according to which there are several ways in which one can be conscious of oneself as oneself – through conscious thoughts, bodily experiences and perceptual experiences – that make distinct determinate contributions to one's phenomenology. This pluralist account provides us with the resources to vindicate the typicalist claim according to which consciousness of oneself as oneself – a sense of self – is pervasive in ordinary conscious experiences, as a matter of contingent empirical fact. It also provides us with the resources to assess the possibility that a subject might be conscious without being conscious of herself as herself in any way. (shrink)

This thesis is set out as a collection of self-standing essays. Throughout these essays, I try to illuminate a number of controversies surrounding the way in which delusions are formed, and relatedly, their nature and epistemic standing. In Chapter 2, after an introductory chapter, I flesh out a new ‘endorsement’ approach to the Capgras delusion, the main idea being that the delusion is formed by endorsing the content of a metaphorical-perceptual state in which a loved one is represented metaphorically as (...) an imposter. In Chapter 3, I take issue with the idea, prevalent in the literature, that Bayesian accounts of inference in delusions are best characterised as versions of ‘explanationism’. Taking one such influential account as a test case, I argue that it is no more or less compatible with the endorsement alternative, which says delusions are acquired non-inferentially from experience. In Chapter 4, I examine a recent critique of predictive processing theories of delusions, according to which such theories suffer two limitations: they fail to explain why an agent believes something delusional as opposed to nothing at all or something else; they fail to explain how delusional hypotheses are generated in the first place. I suggest ways in which these concerns might be addressed. In Chapter 5, I consider how the Spinozan theory of belief fixation can improve the prospects of doxasticism about delusions. Doxasticism has been criticised on the grounds that delusions typically do not abide by rational standards which we expect beliefs to conform to. If belief fixation is Spinozan, I argue, these deviations from rationality are not just compatible with, but supportive of, their status as beliefs. In Chapter 6, I ask whether misidentification delusions formed via endorsement processes have any measure of perceptual justification. To give the best chance of getting a ‘yes’ answer, I address the question from the perspective of perceptual dogmatism, as this appears the best option if we are to grant at least defeasible justifiedness to MDs. I argue that, even so, MDs are completely unjustified. (shrink)

The patient with Capgras’ syndrome claims that people very familiar to him have been replaced by impostors. I argue that this disorder is due to the destruction of a representation that the patient has of the mind of the familiar person. This creates the appearance of a familiar body and face, but without the familiar personality, beliefs, and thoughts. The posterior site of damage in Capgras’ is often reported to be the temporoparietal junction, an area that has a role in (...) the mindreading system, a connected system of cortical areas that allow us to attribute mental states to others. Just as the Capgras’ patient claims that that man is not his father, the patient with asomatognosia claims that his arm is not really his. A similar account applies here, in that a nearby brain area, the supramarginal gyrus, is damaged. This area works in concert with the temporoparietal junction and other areas to produce a large representation of a mind inside a body situated in an environment. Damage to the mind-representing part of this system (coupled with damage to executive processes in the prefrontal lobes) causes Capgras’ syndrome, whereas damage to the body-representing part of this system (also coupled with executive damage) causes asomatognosia. (shrink)

This paper examines Todd Feinberg's theory of the misidentification syndromes.

Hysteria has been the subject of controversy for many years, with theorists arguing about whether it is best explained by a hidden organic cause or by malingering and deception. However, it has been shown that hysterical paralysis cannot be explained in any of these terms. With the recent development of cognitive psychiatry, one may understand psychiatric and organic delusions within the same conceptual framework. Here I contrast hysterical conversion with anosognosia. They are indeed remarkably similar, though the content of their (...) respective delusions is the opposite. In hysterical paralysis, patients are not aware of their preserved ability, whereas in anosognosia for hemiplegia, patients are not aware of their disability. Four main explanations have been provided to account for anosognosia: metacognitive, attentional, motor, and motivational views. I will apply each of these accounts to hysterical paralysis and show that, at each level, hysterical conversion is the reverse of anosognosia. I will suggest that hysterical paralysis results from the interaction between attentional somatosensory amplification and affective inhibition of action. (shrink)