Abstract
How is it possible to perceive things that are not there and believe things that are not true? These are examples of symptoms associated with schizophrenia. In contrast to deficit disorders such as visual agnosia, these positive symptoms reflect creative disorders of consciousness. Such creative experiences imply excessive dependence on top-down processes (e.g. prior beliefs), at the expense of bottom-up processes (e.g. sensations). At this top level of our brain’s hierarchy, estimates of parameters (such as the precision of our prior expectations) become increasingly difficult to compute and can become decoupled from reality.

However, this decoupling has advantages. By sharing our subjective experiences of confidence, superior group decision-making becomes possible. For these advantages to be achieved we need to align our confidence reports with others. This requires decoupling them from our estimates of objective reality. Confidence is one of many subjective experiences that can be modified through interactions with others. At the highest level of our brain’s hierarchy our priors are modified by interactions with other people. This process enables us to acquire shared views of the world, which are crucial for successful communication and for the emergence of culture. In schizophrenia, this high-level decoupling is no longer constrained by interactions with others.

About the speaker
Chris Frith, Emeritus Professor of Neuropsychology, Wellcome Centre for Human Neuroimaging, UCL and Honorary Research Fellow, Institute of Philosophy, University of London.