Abstract

This article is about the neural conundrum behind the slowness of human behavior. The information throughput of a human being is about 10 bits/s. In comparison, our sensory systems gather data at $\sim 1⁢0^9$ bits/s. The stark contrast between these numbers remains unexplained and touches on fundamental aspects of brain function: what neural substrate sets this speed limit on the pace of our existence? Why does the brain need billions of neurons to process 10 bits/s? Why can we only think about one thing at a time? 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. 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.

Links to the paper

Arxiv: includes the first draft (v1) and the latest preprint (v2, same content as on Neuron)

Alphaxiv: includes the discussions about the first draft and author responses. The comments are still being monitored by the authors.

Neuron Perspective: the camera-ready version through the sharable link from the authors

Some media coverage

Endorsed by interviews with the authors

BBC Global News Podcast Dec 24th, 2024. An interview with Prof. Meister, starting at 20:05, and BBC Newsroom, starting at 19:25.

Caltech News Thinking Slowly: The Paradoxical Slowness of Human Behavior

New York Times The Speed of Human Thought Lags Far Behind Your Internet Connection, Study Finds

Scientific American The Human Brain Operates at a Stunningly Slow Pace

The Transmitter Explaining ‘the largest unexplained number in brain science’: Q&A with Markus Meister and Jieyu Zheng

Aviation Week Why Managerial Norms Are Changing To Match New Technologies

More coverage (English)

Discover first coverage on our preprint: The Information Entering Our Brains Dwarfs The Amount Coming Out — Why? and on the published perspective : When It Comes to Thinking, Our Brains Are Surprisingly Slow

Macao News Human brains are slower than early dial-up internet, study finds

Medical Xpress The brain’s processing paradox: Study quantifies the speed of human thought

Smithsonian The Speed of Human Thought Is Far Slower Than the Average Wi-Fi, Study Suggests

Techspot Human thought crawls at 10 bits per second, Caltech study finds

Technology Networks Caltech Scientists Have Quantified the Speed of Human Thought

The Times Wi-fi is faster than your ‘ridiculously slow’ brain

Times India Human brain’s processing speed is far slower than the internet

Yahoo News You’ll Laugh When You Hear How Many Bits Per Second the Human Brain Processes… Once Your Sluggish Human Brain Finally Comprehends It, That Is

Other languages

Helsingin Sanomat Ajatuksiesi nopeus ei ole järin suuri, ja se on nyt mitattu

Muy Interesante Científicos miden la velocidad real del pensamiento humano: el resultado ha causado sorpresa y resuelve el debate “eficiencia vs. velocidad”

Welingelichte Kringen Onze hersenen werken met 10 bits per seconden, WIFI met 50 MB

Rzeczpospolita Naukowcy obliczyli, jak szybko myślą ludzie. Prędkość jest „wyjątkowo niska”

环球科学 人类一生能获得的知识存在上限，科学家已经算出来了

Artistic renditions

Created during the drawing and painting class PVS062 2024.

Selected for display by the Caltech Science and Art Contest (2022).