Circumscribed delusional beliefs can follow brain injury. We suggest that these involve anomalous perceptual experiences created by a deficit to the person's perceptual system, and misinterpretation of these experiences due to biased reasoning. We use the Capgras delusion (the claim that one or more of one's close relatives has been replaced by an exact replica or impostor) to illustrate this argument. Our account maintains that people voicing this delusion suffer an impairment that leads to faces being perceived as drained of (...) their normal affective significance, and an additional reasoning bias that leads them to put greater weight on forming beliefs that are observationally adequate rather than beliefs that are a conservative extension of their existing stock. We show how this position can integrate issues involved in the philosophy and psychology of belief, and examine the scope for mutually beneficial interaction. (shrink)

Circumscribed delusional beliefs can follow brain injury. We suggest that these involve anomalous perceptual experiences created by a deficit to the person's perceptual system, and misinterpretation of these experiences due to biased reasoning. We use the Capgras delusion (the claim that one or more of one's close relatives has been replaced by an exact replica or impostor) to illustrate this argument. Our account maintains that people voicing this delusion suffer an impairment that leads to faces being perceived as drained of (...) their normal affective significance, and an additional reasoning bias that leads them to put greater weight on forming beliefs that are observationally adequate rather than beliefs that are a conservative extension of their existing stock. We show how this position can integrate issues involved in the philosophy and psychology of belief, and examine the scope for mutually beneficial interaction. (shrink)

INTRODUCTION TO ASPECTS OF FACE PROCESSING: TEN QUESTIONS IN NEED OF ANSWERS. HD Ellis 1. INTRODUCTION These proceedings of the first international ...

Detailed studies of people who have experienced the Capgras delusion (the delusion that certain other people, usually close relatives, have been replaced by impostors) have led to advances in constructing an account which can deal with the basic symptomatology, testing alternative possibilities, generating and testing non‐trivial predictions, and broadening the scope of the basic account to encompass other delusions. This paper outlines these developments. It uses them to explore implications for understanding the formation and maintenance of beliefs, and to discuss (...) basic principles of what has come to be known as cognitive neuropsychiatry. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Philosophy, Psychiatry, & Psychology 9.1 (2002) 55-59 [Access article in PDF] One Stage Is Not Enough Andrew W. Young and Karel W. de Pauw Keywords: delusions, Cotard delusion, Capgras delusion, cognitive neuropsychiatry. WE WELCOME THE OPPORTUNITY to offer our reflections on Philip Gerrans' interesting paper. Our opinion is that on fundamental issues we agree quite a bit—but there are clear differences when it comes to details.The most basic issue (...) concerns the nature of the enterprise. Like Gerrans, we think that it is possible to create testable accounts of the formation and maintenance of what would otherwise seem bizarre and inexplicable delusions, and that these accounts should be grounded in theoretical models of factors that underpin our everyday perception and reasoning. This general approach certainly forms part of what has been called cognitive neuropsychiatry. However, we disagree with Gerrans in that we see cognitive neuropsychiatry as an attempt to draw on the underlying logic of cognitive neuropsychology, rather than (as Gerrans implies) its current methods. The underlying logic of cognitive neuropsychological approaches has been to try to understand the effects of brain injury in terms of disruption of different components of theoretical models of normal abilities. In this approach, a model of normal performance is tested by its ability to account for the effects of brain injury. Where the model of normal performance also provides a convincing account of brain injury it is retained, and when it fails to account for effects of brain injury, it is revised or abandoned. In cognitive neuropsychiatry, the key theoretical move has been to argue that an adequate model of normal performance should be able to account for any disordered pattern (Ellis and Young 1990). The same logic of seeking to explain disordered performance by reference to models of normal function is then attempted, but for disorders that would usually fall within the province of psychiatry.In our opinion, however, cognitive neuropsychiatry will not simply involve importing the methods of cognitive neuropsychology into the new domain; they will need to be developed and adapted to fit the new agenda (Young 2000).In cognitive neuropsychology, progress has often come from the careful investigation of people with stable, selective deficits of fundamental cognitive functions involved in sensory analysis, memory, and verbal or motor output. In contrast, delusional beliefs can be relatively unstable; often they are only held for a few weeks or even days. When the delusions change, patients may modify or abandon them as suddenly as they seemed to form them, or they may give them up much more slowly and reluctantly. At the very least, this creates difficulties in the timing of investigations and in interpreting the relation of deficits and symptoms, which may be recorded on separate dates. These methodological problems [End Page 55] are exacerbated by the fact that deficits linked to complex abnormal experiences such as delusions may be multifaceted and diffuse, even when the delusions themselves have a specific content or theme. Such complications do not invalidate cognitive neuropsychiatry, but they do mean it will need to develop its own methods for dealing with them and making appropriate inferences.One of the key complexities that has surfaced already involves the idea that delusional beliefs might reflect the interaction of two or more contributory factors. Gerrans discusses a particular variant of this idea, which had been suggested by Young and Leafhead (1996) as an approach to understanding the Cotard delusion: The Cotard delusion represents a depressed person's attempt to account for abnormal perceptual experiences. It follows that the delusion is based on an unfortunate interaction between different contributory factors. One set of factors creates the abnormal perceptual experiences, which are characterised by lack of emotional responses and feelings of emptiness, depersonalisation and derealisation. The other factors result in a misinterpretation of these perceptual changes, in which the patients' depressed moods lead them correctly to attribute the changes to themselves, but to exaggerate their consequences. (Young and Leafhead, 1996, 166) Gerrans describes this as a two-stage account, but argues that a one-stage account based only on abnormal perceptual... (shrink)

ABSTRACTRecognising identity and emotion conveyed by the face is important for successful social interactions and has thus been the focus of considerable research. Debate has surrounded the extent...

In Act 1 scene iv of Macbeth, Duncan reflects that: 'There's no art to find the mind's construction in the face'. In contrast, the claim that Andy Young sets out in this book is that we are now developing a science of face perception which can indeed shed light on certain aspects of mentallife. Face and Mind consists of a series of seminal research and review papers on face perception published by the author and his colleagues over the last 12 (...) years. A comprehensive introductory chapter, written especially for this volume, serves to draw together the various themes explored in thedifferent contributions. The book examines the question of how faces are special, in terms of their social, biological, and theoretical roles. In particular, Face and Mind seeks to determine what our understanding of the face can tell us about the human brain. It discusses the evidence for anevolved neural substrate for face perception, and the question of whether we are innately predisposed to recognise faces, to find them attractive, and to decode the many social signals they give us. The ability of the human brain to process and remember the many different faces that we see andsubsequently recall is analysed. Young includes detailed studies of the types of impairment to face perception which can follow brain injury or psychiatric illness, and uses them to address these questions, as well as other issues of high intrinsic and interdisciplinary interest. These include theextent to which our mental lives result from the operation of discrete components devoted to different purposes, the differences between conscious and non-conscious processes, and how we use evidence to support our beliefs about the world. Because of the huge variety of social signals read from theface, it can offer unique theoretical and philosophical insights into these questions. This fascinating book will be of interest not only to psychologists and neuropsychologists working in the field of visual perception, but to cognitive scientists generally. It provides an excellent summary ofthe most important theorietical and empirical work done on face perception in recent years, and as such will be of interest to advanced undergraduate and post-graduate students in psychology, philosophy, and cognitive science. (shrink)

Volume 34, Issue 8, December 2020, Page 1621-1631.

CHAPTER 1 Neurotransmitter networks Elaine Perry and Allan Young i. Introduction This first chapter sets the scene for subsequent exploration of potential ...

This article gives an overview of what we can learn about face perception from studying its disorders. The term “disorders” is broadly interpreted to include acquired brain injury and disease, neurodevelopmental differences, and neuropsychiatric problems. The article examines the reasons for various opinions about what can be learnt from disorders, ranging from the entire spectrum from “nothing that isn't misleading” to “everything worth knowing.” Cognitive neuropsychology typically operates in a unique way, in which the emphasis is on detailed analysis of (...) individual patients with theoretically interesting impairments. The article then highlights a number of the assumptions that get made, explains why things are often complicated, and emphasizes the value of a pragmatic “converging operations” approach in which evidence from disorders of face perception is brought together with other sources of data and theory. (shrink)

Some cases of prosopagnosia involve a highly circumscribed loss of A-consciousness. When seen in this way they offer further support for the arguments made in Block's target article.