Imperfect Cognitions

This is the fifth and final post in a series of posts on the papers published in an issue of Avant on Delusions. Here Glenn Carruthers (pictured above) summarises his paper ' Difficulties for Extending Wegner and Colleagues' Model of the Sense of Agency to Deficits in Delusions of Alien Control '. One of Christopher Frith's (e.g.  1992 ) ideas that has really taken hold is that part of the problem in delusions of alien control is a deficit in the sense of agency. Given that the sense of agency is the feeling that one controls one's actions we can see how a deficit in this feeling could lead to people saying things like: When I reach my hand for the comb it is my hand and arm which move, and my fingers pick up the pen, but I don’t control them… I sit there watching them move, and they are quite independent, what they do is nothing to do with me… I am just a puppet who is manipulated by cosmic strings. When the strings are pulled my body moves and I cannot p...

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...

This is our third of a series of posts in the papers published in an issue of Avant on Delusions. Here  Rick Adams  summarises his paper (co-written with Harriet R. Brown and Karl J. Friston ) ' Bayesian Inference, Predictive Coding and Delusions '. I am in training to become a psychiatrist. I have also recently completed a PhD at UCL under Prof Karl Friston , a renowned computational neuroscientist. I am part of a new field known as Computational Psychiatry (CP). CP tries to explain how various phenomena in psychiatry could be understood in terms of brain computations (see also Corlett and Fletcher 2014 , Montague et al.,  2012 , and Adams et al. forthcoming in JNNP ). One phenomenon that ought to be amenable to a computational understanding is the formation of both ‘normal’ beliefs (i.e. beliefs which are generally agreed to be reasonable) and delusions. There are strong theoretical reasons to suppose that we (and other organisms) form beliefs in a Bayesi...

This is the second in a series of posts on the papers published in an issue of Avant on Delusions. Here Kengo Miyazono summarises his paper (co-written with Lisa Bortolotti ) ' The Causal Role Argument Against Doxasticism About Delusions '. Doxasticism about delusion is the claim that delusions are beliefs. Delusions are usually regarded as beliefs in psychiatry. For instance, in the DSM-5 delusion is defined as a 'false belief based on incorrect inference about external reality that is firmly held despite what almost everyone else believes and despite what constitutes incontrovertible and obvious proof or evidence to the contrary' (American Psychiatric Association 2013: 819). Moreover, cognitive scientists working on theories of delusion formation assume that the mechanisms responsible for the formation of delusions are also the mechanisms responsible for the formation of beliefs ( Coltheart 2007 ; Corlett et al. 2010 ). However, doxasticism is not very...

Max Coltheart This is the first in a series of posts on the papers published in an issue of AVANT on Delusions. Here  Max Coltheart  summarises his paper  ' From the Internal Lexicon to Delusional Belief '. Ten years ago, in an article on the two-factor theory of delusion, I wrote:  'Suppose that as we go about everyday life we use an internal model of the world (Gray  1995 ;  Sokolov  1963 ) to continuously predict what we will experience next. These predictions will normally be fulfilled, but occasionally not: occasionally something not predicted by the internal model occurs. That event indicates that there is something wrong with the database of beliefs that the model uses to predict what will happen next in the world. So the database needs to be fixed (by modifying e xisting beliefs or adopting new ones) so that it becomes compatible with the unexpected event' (Coltheart 2005 ). As I emphasize in my Avant  article, this is th...