You do not use ten percent of your brain. Scans light up across the whole of it in a day.

What it means

The claim has no source in neuroscience and appears to have grown out of misreported remarks and self improvement advertising. Imaging shows activity throughout the brain over the course of ordinary tasks, and there is no large region that can be lost without consequence. Damage almost anywhere in the brain produces a deficit, which is exactly what you would not expect if most of it were spare.

The claim comes from Frontiers in Psychology, and the page it comes from was read on 2026-08-27 to confirm it still says this.

This is not the kind of claim that goes out of date, which is why it was set as a puzzle rather than a fact with a shelf life.

Solve it yourself

This fact is a cryptogram here: 68 letters over 19 different ones, graded medium.

Go to the puzzle

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The facts either side of this one.

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About as hard as this one

Scored closest to it by the model behind our guide to solving cryptograms.

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