The viewpoint that single neurons are the functional units of the brain rests on the hypothesis that each neuron has a single function or “message”.  This notion has eroded under observations that cortical neurons do not seem to do one thing.  Instead, neurons often respond to diverse combinations of task relevant variables, and often a variety of different variables with no apparent single function.  Why would the brain evolve neurons with this “mixed selectivity”?  In short, they add computational power.  How?  Read this paper and we”ll tell you.

Why neurons mix: high dimensionality for higher cognition,
Stefano Fusi, Earl K Miller, Mattia Rigotti,
Current Opinion in Neurobiology, Volume 37, April 2016, Pages 66-74, ISSN 0959-4388,

About the Author

The Miller Lab uses experimental and theoretical approaches to study the neural basis of the high-level cognitive functions that underlie complex goal-directed behavior.