You’ve probably heard the myth that the average person uses only 10 percent of their brain. It’s a seductive lie because it suggests that we could be more than we are. Sci-fi movies like Limitless and Lucy, whose protagonists gain super-human abilities by accessing latent mental capacities, have exploited the myth. Neuroscientists, on the other hand, have long loathed it. Eighty years of studies confirm that every part of the brain is active throughout the course of a day. Save those who have suffered serious brain injury, we use all of our brains, all of the time.
But, like many legends, the 10 percent myth also carries a grain of truth. In the last 20 years, scientists have discovered that our cortex follows a strangely familiar pattern: A small minority of neurons output the vast majority of activity. It’s not that we don’t use 90 percent of our brain, but that many neurons remain eerily quiet even during use. The story behind this silence is more profound than the boosted IQs and temporary clairvoyance from the movies. It speaks to the basic principles of how our minds represent reality in the first place.