The idea that humans only use 10% of their brain is a myth. Research using brain imaging techniques like fMRI shows that almost all of the brain is active most of the time, even during simple tasks or rest. While not all neurons fire simultaneously, over the course of a day we use virtually every part of the brain. The brain consumes a significant amount of energy and is highly active both awake and asleep, indicating widespread usage rather than limited capacity.

Origins and Explanation of the Myth

The myth may have originated from early misunderstandings of brain function and mental capacity, with figures like William James suggesting humans only tap part of their mental resources but not specifying a percentage. It has been perpetuated by popular culture, books, and movies.

Brain Activity and Energy Use

The brain is about 2% of the body's weight but uses about 20% of its energy. It operates with a mechanism called sparse coding, meaning a small proportion of neurons are active at any given moment but the whole brain has specific functions and is used throughout.

Conclusion

Humans use nearly 100% of their brains over time, not just 10%. The brain is a complex organ with various specialized regions actively engaged depending on tasks, thoughts, and states like sleep.