Me and My Markov Blanket: Sentience and the Free Energy Principle
How can we understand ourselves as sentient creatures able to perceive or feel things? What principles underwrite this behavior? To answer these questions, Karl Friston explored sentience from the point of view of a physicist and then rehearsed the same story from the point of view of a neurobiologist.
The lecture began with a heuristic proof suggesting that life — or any biological self-organization — is an inevitable and emergent property of any dynamical system that possesses a Markov blanket. In biology, a Markov blanket is a system’s boundary. The perfect example is a cell membrane that separates intracellular organelles from the extracellular. When the internal and external states are conditionally independent, it can equip the internal states with an information geometry pertaining to probabilistic beliefs about something; namely the external states. This free energy is the same quantity that is optimized in machine learning. In short, internal states will appear to infer — and act on — their world to preserve their integrity.
In the second half of the talk, Friston unpacked these ideas using simulations of Bayesian belief (a model usually used in mathematical statistics) updating in the brain and related them to predictive processing and sentient behavior.
About the Theoretical Neuroscientist
Karl Friston is a theoretical neuroscientist and authority on brain imaging. He invented statistical parametric mapping (SPM), voxel-based morphometry (VBM) and dynamic causal modelling (DCM). These contributions were motivated by schizophrenia research and theoretical studies of value-learning, formulated as the dysconnection hypothesis of schizophrenia. Friston currently works on models of functional integration in the human brain and the principles that underlie neuronal interactions. His main contribution to theoretical neurobiology is a free-energy principle for action and perception (active inference). He was the 2016 recipient of the Charles Branch Award for unparalleled breakthroughs in Brain Research and the Glass Brain Award, a lifetime achievement award in the field of human brain mapping. He holds Honorary Doctorates from the University of Zurich and Radboud University.
