"The brain is famously noisy, and...noise in computation may reduce total thermodynamic work." (Neuron, istockphoto.com)

Any highly precise computation—whether it is a decision made in the brain, the metabolic processes of a cell or the function of a computer—requires energy, but imprecise, noisy computations can actually cool a system. This has major implications for biological systems, writes SFI Professor David Wolpert in a new analysis published in the journal Entropy. Some computations done by a biological organism require extreme precision—when survival depends on making the right decision, for instance— and therefore require the organism to get more energy, i.e., food. However other computations can be imprecise, and so don’t require that the organism feed more. 

“There is a massive pressure in natural selection, which nobody has modeled before, for organisms to try to perform computations that are as noisy as possible in light of this trade-off,” says Wolpert. “You only want to be precise where it’s fitness-relevant.”

Read the article in Entropy (June 2, 2016)