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 Examples include Capgras delusion, the delusion that a loved one has been replaced by an impostor, and Cotard delusion, the delusion that one is dead or does not exist.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)

In this paper, we defend a representational approach to at least some kinds of non-human psychopathology. Mentally-ill non-human minds, in particular in delusions, obsessive-compulsive disorders and similar cognitive states, are traditionally understood in purely behavioral terms. In contrast, we argue that non-human mental psychopathology should be at least sometimes not only ascribed contentful mental representation but also understood as really having these states. To defend this view, we appeal to the interactivist account of mental representation, which is a kind of (...) a constructive approach to meaning. We follow Mark Bickhard in assuming that only an organism – either human or non-human – capable of detecting its own misrepresentations is representational. However, under his autonomy-based account of biological function these minds are incapable of misrepresentations because these minds are, ex hypothesi, unable to detect error in such representations. To solve this problem, we argue that adding a historical dimension – as in Millikan’s view on mental representations – to Bickhard’s account of function makes mental misrepresentation of mentally-ill minds possible. Using Bickhard’s dynamic account of function, it is possible to explain why delusions and other mental disorders can be seen as locally functional. However, an etiological dimension can further explain why misrepresentations seem to be globally dysfunctional. Even if representational or biosemiotic hypotheses about non-human psychopathology are difficult to confirm empirically, we defend the view that they can enrich our understanding of the causes and development of such pathologies, and may constitute a new progressive research programme. (shrink)

Clinical delusions are difficult to investigate in the laboratory because they co-occur with other symptoms and with intellectual impairment. Partly for these reasons, researchers have recently begun to use hypnosis with neurologically intact people in order to model clinical delusions. In this paper we describe striking analogies between the behavior of patients with a clinical delusion of mirrored self misidentification, and the behavior of highly hypnotizable subjects who receive a hypnotic suggestion to see a stranger when they look in the (...) mirror. Based on these analogies, we argue that the use of hypnosis is a reliable method to investigate the surface features of clinical delusions. But to what extent can hypnosis successfully recreate delusions? Can it also contribute to a better understanding of delusion formation? Although clinical delusions and hypnotically induced beliefs are different in etiology, some analogies can be identified in the underlying processes that characterise them, based on the two-factor theory of delusion formation. (shrink)

ABSTRACTThis article intends to reconsider the epistemological status of delusional beliefs on the basis of Wittgenstein’s conception of certainty. Several works over the last two decades have compared delusional beliefs with so-called hinge propositions, which – according to Wittgenstein – function as expressions of objective certainty. This gives rise to a paradox. On the one hand, delusions are compatible to Wittgensteinian certainties in some respects; on the other hand, they contradict beliefs shared by other members of the community, which makes (...) them different from ‘normal’ certainties. In order to address this issue, I use Moyal-Sharrock’s taxonomy of hinge propositions. This taxonomy allows one to distinguish between different types of hinge propositions; all types share the same features, but these features are manifested in a variety of ways. Thus, delusional beliefs might also be regarded as constituting a specific type of hinge propositions. This move makes it possible to resolve the paradox and to identify the special epistemic features of delusional beliefs. (shrink)