Steve FlemmingWellcome Centre for Human Neuroimaging, University College London
Conscious awareness as inference in a higher-order state space, by Stephen Fleming
Summary: Humans have the ability to report the contents of their subjective experience – we can say to each other, “I am aware of X”. However, the decision processes that support reports about mental contents remain poorly understood. In this article I propose a computational framework that characterises awareness reports as metacognitive decisions (inference) about a generative model of perceptual content. This account is motivated from the perspective of how flexible hierarchical state spaces are built during learning and decision-making. Internal states supporting awareness reports, unlike those covarying with perceptual contents, are simple and abstract, varying along a one-dimensional continuum from absent to present. A critical feature of this architecture is that it is both higher-order and asymmetric: there is a vast number of possible states nested under “present”, but a much smaller number of possible states nested under “absent”. A critical prediction of this framework (in contrast to global workspace approaches) is that there should be higher-order, symmetric neural coding of both presence and absence. In my talk I will first demonstrate this in simulation, before presenting the results of a recent experiment in which we identify evidence for such symmetry in human frontopolar and temporoparietal cortex. I interpret these results as initial evidence in favour of the higher-order state space view.
Short Biography: Steve Fleming is a Sir Henry Dale Wellcome Trust/Royal Society Fellow at the Wellcome Centre for Human Neuroimaging, University College London where he leads the Metacognition Group. The group’s research focuses on the mechanisms supporting conscious awareness, metacognition and decision-making in the adult human brain. Read more