Letter: Essence of thought

From Robert P. Erickson, Department of Neurobiology, Duke University

Some perspective is needed on Gregory T. Huang’s position that the model developed by neuroscientist Karl Friston approaches a new and “grand theory” of brain function (31 May, p 30). The brain updating probabilities of what to expect from the world is certainly important – essentially it is the long-discussed phenomenon of learning. But this is frosting on the cake, not the cake itself.

The more basic topics not addressed by Friston include: how information is represented, how motivation can modify behaviour, how behaviour is elicited (decision-making), and the intimate nature of the expectancy and the learning process that he discusses. His model does not deal with these core issues, and so cannot be seen as an all-encompassing, E = mc² -style summary of brain function.

His view of the plasticity of these core functions may be a useful part of a more general understanding, but the grand view is yet to be approached.

I have proposed that there is a largely common neural language across all brain systems – set out in “A study of the science of taste: On the origins and influence of the core ideas” (Behavioral and Brain Sciences, vol 31, p 59). It has been widely rejected by specialists in the fields of taste and other sensory systems, so it must be interesting.

Durham, North Carolina, US