a1 Department of Psychiatry, Brain Mapping Unit and Behavioural and Clinical Neurosciences Institute, University of Cambridge, School of Clinical Medicine, and Addenbrooke's Hospital, Cambridge CB2 2QQ, United Kingdom [email protected]
a2 Department of Psychiatry, Clinical Neuroscience Research Unit, Yale University School of Medicine, Connecticut Mental Health Center, New Haven, CT 06519
a3 Department of Psychiatry, Abraham Ribicoff Research Facilities, Yale University School of Medicine, Connecticut Mental Health Center, New Haven, CT 06519. [email protected]
In their target article, McKay & Dennett (M&D) conclude that only “positive illusions” are adaptive misbeliefs. Relying on overly strict conceptual schisms (deficit vs. motivational, functional vs. organic, perception vs. belief), they prematurely discount delusions as biologically adaptive. In contrast to their view that “motivation” plays a psychological but not a biological function in a two-factor model of the forming and maintenance of delusions, we propose a single impairment in prediction-error–driven (i.e., motivational) learning in three stages in which delusions play a biologically adaptive role.