Our brain works slower than a 50-year-old processor – scientists from Caltech measured the speed of human thought

Researchers from the California Institute of Technology (Caltech) were able to estimate the speed of human thought – it was only 10 bits per second – even processors 40 years ago were faster. Human sensory systems collect data about the environment at a rate of a billion bits per second, which is 100 million times faster than the speed of mental processes. The researchers relied on information theory methods and data on human behavior: reading, writing, video games and solving the Rubik’s cube.

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«This is an extremely low number,” says study leader Professor Markus Meister. – Every moment we extract only 10 bits out of a trillion that our senses perceive, and use these 10 to perceive the world around us and make decisions. This creates a paradox: what does the brain do to filter all this information?”

The human brain contains more than 85 billion neurons, a third of which are located in the cerebral cortex and are involved in high-level thinking. Individual neurons are powerful information processors and can easily transmit more than 10 bits of information per second, but for some reason they don’t. Meister believes neuroscientists should address these paradoxes in future research.

Another question the new research raises is why the brain processes one thought at a time, rather than several in parallel, as our sensory systems do. For example, a chess player contemplating his next move might explore only one possible sequence at a time, rather than several at once. Researchers have suggested that this may have something to do with the way our brains developed.

The earliest creatures with primitive nervous systems used their brains primarily for navigation, to find food and to hide from predators. If the human brain evolved from these simple systems, it makes sense that it can only follow one “path” of thought at a time. “Human thinking can be viewed as a form of navigation in the space of abstract concepts,” the researchers say. They believe that this limitation—one thought per “cycle”—is encoded in the brain’s architecture.

«Our ancestors chose an ecological niche where the world was slow enough to make survival possible, scientists believe. “In reality, 10 bits per second is only needed in the worst situations, and most of the time our environment changes at a much more leisurely pace.”

A new assessment of the speed of human thinking may disprove some futuristic scenarios. It appears that dreams of a direct high-speed interface between the human brain and a computer will remain a dream, as the human brain will slowly communicate through a neural interface at 10 bits per second.