The history of the future of the Bayesian brain

• Published in: NeuroImage (Orlando, Fla.) Vol. 62; no. 2; pp. 1230 - 1233
• Main Author: Friston, Karl
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.08.2012; Elsevier Limited; Academic Press
• Subjects: Anatomy & physiology; Animals; Bayes Theorem; Bayesian brain; Brain - physiology; Decision making; Effective connectivity; Free energy; Functional integration; Generative models; History, 20th Century; History, 21st Century; Humans; Hypotheses; Hypothesis testing; Inference; Information theory; Medical imaging; Models, Neurological; Neuroimaging - history; Neuroimaging - trends; Neurosciences; Neurosciences - history; Neurosciences - trends; Optimization; Predictive coding; Review; Theory; Functional integration; Predictive coding; Inference; Generative models; Bayesian brain; Optimization; Free energy; Effective connectivity
• ISSN: 1053-8119; 1095-9572; 1095-9572
• DOI: 10.1016/j.neuroimage.2011.10.004

The slight perversion of the original title of this piece (The Future of the Bayesian Brain) reflects my attempt to write prospectively about ‘Science and Stories’ over the past 20years. I will meet this challenge by dealing with the future and then turning to its history. The future of the Bayesian brain (in neuroimaging) is clear: it is the application of dynamic causal modeling to understand how the brain conforms to the free energy principle. In this context, the Bayesian brain is a corollary of the free energy principle, which says that any self organizing system (like a brain or neuroimaging community) must maximize the evidence for its own existence, which means it must minimize its free energy using a model of its world. Dynamic causal modeling involves finding models of the brain that have the greatest evidence or the lowest free energy. In short, the future of imaging neuroscience is to refine models of the brain to minimize free energy, where the brain refines models of the world to minimize free energy. This endeavor itself minimizes free energy because our community is itself a self organizing system. I cannot imagine an alternative future that has the same beautiful self consistency as mine. Having dispensed with the future, we can now focus on the past, which is much more interesting: