Imperfect Cognitions

Today's post is by Dan Williams, a PhD candidate in the Faculty of Philosophy, at the University of Cambridge. If you had to bet on it, what’s the probability that your loved ones have been replaced by visually indistinguishable imposters? That your body is overrun with tiny parasites? That you’re dead? As strange as these possibilities are, each of them captures the content of well-known delusional beliefs: Capgras delusion, delusional parasitosis, and Cotard delusion respectively. Delusional beliefs come in a wide variety of forms and arise from a comparably diverse range of underlying causes. One of the deepest challenges in the contemporary mind sciences is to explain them. Why do people form such delusions? And why on earth do they retain them in the face of seemingly overwhelming evidence against them? My new paper “ Hierarchical Bayesian Models of Delusion ” presents a review and critique of a fascinating body of research in computational psychiatry that at...

Colin Klein We are philosophers working on various topics that intersect with delusions. Colin Klein works on the philosophy of neuroscience and the application of interventionist accounts of causation to this area, and has also discussed the relation between psychopathologies like somatoparaphenia and his theory of pain . Stephen Gadsby works on distorted body representations and false body size beliefs in anorexia nervosa . And Peter Clutton has defended the doxastic status of delusions—offering a cognitive phenomenological account of delusions (forthcoming)—and explored the status of delusions on the harmful dysfunction account . Peter Clutton Any discussion of delusions needs some criteria by which patients are grouped together as having the same delusion. In our paper, ‘ Taxonomising Delusions: content or aetiology? ’, we compare content-based and aetiological taxonomies of delusions, arguing in favour of the latter. Stephen Gadsby Most authors ta...

This is the fourth in a series of posts on the papers published in an issue of Avant on Delusions. Here Garry Young summarises his paper ' Amending the Revisionist Model of the Capgras Delusion: A Further Argument for the Role of Patient Experience in Delusional Belief Formation '. I currently work as a senior lecturer in psychology at Nottingham Trent University, although my postgraduate studies were in philosophy. My research interests cover three distinct areas. First, I am interested in embodied cognition, particularly the relationship between consciousness and procedural knowledge (knowing how to do something, rather than knowledge of facts). I have argued, using cases of visual pathology (e.g. blindsight and visual agnosia), that a form of knowledge-how (knowing how to do something) can occur in the absence of conscious accompaniment.  I am also interested in the ethics underlying the virtual enactment of real-world taboos, such as murder or physical/sexual assault...