I am a professor in the Department of Bio and Brain Engineering at KAIST in South Korea. I was trained in cellular and systems neurophysiology, and now work on theory. For my doctoral thesis I studied the cellular electrophysiology of midbrain dopamine neurons in brain slices, especially in relation to addictive drugs, under the supervision of John T. Williams at Oregon Health and Science University. I did postdoctoral research with Wolfram Schultz at University of Cambridge and William T. Newsome at Stanford University, recording from midbrain dopamine neurons in behaving animals.
These neurons release the neurotransmitter dopamine to signal “reward prediction error.” This error signal teaches the brain the reward value of stimuli and actions (a process known as “reinforcement learning”). By 2003, soon after I began studying these prediction errors, I came to see prediction as the general function of the brain. More specifically, the function of the brain is to predict and thereby cause survival and reproduction. Since a prediction is determined by evidence (which I use here as a synonym of knowledge and information), another way to say this is that the purpose of a brain is to concentrate evidence for its own future existence.
In 2008 I published a general theory of the brain based on this idea and “the neuron’s point of view” (Fiorillo, 2008). My students and I subsequently worked to test the theory (e.g., Kim and Fiorillo, 2017). More recently I have been working to better understand evidence, both mathematically and physically (e.g., Fiorillo and Kim, 2021). The major result of this effort is Rational Observer Theory, a general physical theory in which what exists is evidence.
It is easy to get confused about evidence, particularly since every observer has distinct local evidence, and that evidence is continually changing. I believe that confusion about the concept of evidence, and the closely related concept of an observer/observation, is the major problem within science today (see Science’s Problem with Reality and Science’s Observation Problem). This confusion has severely limited the scope of science, as well as progress toward solving every conceptually difficult problem we encounter, from the nature of space and time to the relation of mind and body. I see evidence as the most fundamental and important of all concepts. From it all else follows.
I can be contacted via gmail with questions or comments at rationalobserver137.