A Human Speed

The human brain is capable of limitless imagination, but that doesn’t mean it’s superfast.

Scientists recently discovered that when it comes to thinking, our noggins operate at an average speed of just 10 bits per second (bps).

This rate pales in comparison with the billion bps processed by the sensory systems, revealing a significant mismatch between perception and cognition, according to a new study.

“This is an extremely low number,” explained Markus Meister, a neuroscientist at the California Institute of Technology and co-author of the paper, in a statement. “Every moment, we are extracting just 10 bits from the trillion that our senses are taking in and using those 10 to perceive the world around us and make decisions.”

Meister and his colleague Jieyu Zheng analyzed nearly a century of research across neuroscience, psychology, and human performance to calculate this cognitive bottleneck.

From reading to solving Rubik’s Cubes, human decision-making consistently hovers around 10 bps – a speed comparable to casual typing.

The study raises a series of questions, such as how can individual neurons in the brain transmit far more than 10 bps and how can one-third of the brain’s 85 billion neurons be dedicated to high-level thinking.

Adding to this puzzle is why humans can only focus on one thought at a time, while sensory systems process multiple inputs simultaneously.

Meister and Zheng theorized that this sluggishness could be evolutionary: Early nervous systems primarily helped organisms navigate toward food or away from danger, tasks that require following a single path.

This limitation persists in modern humans, the team explained, likening human thought to “navigation through a space of abstract concepts.”

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

Other neuroscientists told Scientific American that the findings could reshape neuroscience, prompting researchers to explore how this bottleneck affects complex tasks such as planning and problem-solving.

“Nature, it seems, has built a speed limit into our conscious thoughts, and no amount of neural engineering may be able to bypass it,” said neuroscientist Tony Zador, who was not involved in the study. “Why? We really don’t know, but it’s likely the result of our evolutionary history.”