Humans think slower than expected, study finds

Human brains are not computers, in spite of how often such a comparison is made, but a recent study in the journal Neuron reveals our gray matter is quite pokey even when compared to Wi-Fi speeds.

Researchers from the California Institute of Technology calculated the speed at which humans performed tasks that can be quantified as "information processing." For example, they figured out the speed at which people can solve a Rubik’s Cube, memorize numbers, play Tetris and remember random orders in a deck of cards. Reducing this data into “bits,” wherein quantities are measured through a binary code (0s and 1s), the scientists then calculated the overall “speed” at which the brain processes this information.

Ultimately they concluded that the average rate of human thought is roughly 10 bits per second. By contrast, Wi-Fi speeds are usually measured in hundreds of millions of bits per second, while the human eye processes information at 100 million bits per second.

“The brain seems to operate in two distinct modes: the ‘outer’ brain handles fast high-dimensional sensory and motor signals, whereas the ‘inner’ brain processes the reduced few bits needed to control behavior,” the authors write. “Plausible explanations exist for the large neuron numbers in the outer brain, but not for the inner brain, and we propose new research directions to remedy this.”

It may seem counterintuitive to refer to a large number of neurons in the outer brain after learning that humans think so slowly, but in fact the experts believe our speed of thought is more than sufficient for our evolutionary needs. The earliest creatures to develop central nervous systems did so in order to move toward food and away from predators. From there, the brain simply continued to develop using this linear mode of thinking, as a kluge rather than a rationally designed machine. When our brains process abstract concepts, it is engaging in the same basic activity that it employs when navigating. For these purposes, 10 bits per second does the job.

"Our ancestors have chosen an ecological niche where the world is slow enough to make survival possible," the authors write. "In fact, the 10 bits per second are needed only in worst-case situations, and most of the time our environment changes at a much more leisurely pace."