Does the Brain Work Logarithmically?

New research suggests it does, when it’s the efficient way to process information


Steven Cherry: Hi, this is Steven Cherry for IEEE Spectrum’s “Techwise Conversations.”

It seems automatic to us that the midpoint between 1 and 9 is 5, but if you think about it, it’s not at all obvious that that our brains are wired for a linear scale. In fact, in many situations, we perceive the world logarithmically.

It makes sense. The difference between 1 and 3 gazelles, if you’re hunting gazelles, is as important as the difference between 3 and 9—and on a log scale, 3 to the first power is halfway between 3 to the zeroth and 3 squared.

As numbers get larger, logarithms tend to flatten things out, and sure enough, add 20, say, and the difference between 29 gazelles and 23—or even 21—is hardly noticeable at all.

To some extent, this has been known for some time. The Weber–Fechner law, actually two laws, goes back more than 100 years and uses a logarithm in giving the ratio of physical stimuli to perceived intensity. But some new research, published in the Journal of Mathematical Psychology, has found a neurobiological basis for this for the first time. And what’s more, it also theorizes that the brain wiring responsible for it has a correlate when it comes to electronic information systems. [read more..]