Stop Believing Limitless: We Actually Use 100% of Our Brains

"Humans only use 10% of their brains"—this claim is so widespread that it has become a go-to premise in science fiction films. From Lucy to Limitless, Hollywood repeatedly tells us that unlocking the remaining brainpower will grant us superhuman abilities. But neuroscience says the opposite: we use all of our brains, all the time—and it never "goes dormant."

Where the 10% Myth Came From and Why It Doesn't Hold Up

The origins of this myth are hard to trace, but it clearly caters to a romantic notion of "untapped potential." From a physiological standpoint, however, the brain is one of the body's most "luxurious" organs—it consumes enormous energy and resources despite accounting for only a small fraction of body weight. If 90% of the brain were truly idle, evolution would have eliminated it long ago, since maintaining useless tissue offers no survival advantage.

More importantly, modern brain imaging has never found any "silent" region. Whether at rest or thinking, every part of the brain maintains some level of activity. The claim that we "only use 10%" has no foothold whatsoever in neuroscience.

How Brain Imaging Proves "Whole-Brain Activity"

The "modern brain imaging techniques" mentioned above mainly include functional magnetic resonance imaging (fMRI) and positron emission tomography (PET). fMRI indirectly reflects neuronal activity by detecting blood-oxygen-level-dependent (BOLD) signals: when a brain region is active, local blood flow and oxygenated hemoglobin increase, producing a high signal on the image. PET measures glucose metabolism rates by injecting radioactive tracers, directly reflecting energy consumption. Numerous resting-state fMRI studies show that even when performing no task, the brain exhibits widespread connectivity such as the default mode network, with spontaneous activity in all regions. Although these techniques have limited temporal and spatial resolution, they are more than sufficient to refute the claim that "90% of the brain is silent"—no whole-brain scan has ever shown large areas of zero activity.

What Hollywood's "Superpower" Narrative Gets Wrong

A neuroscience storyteller mentioned in an interview that her ex-husband once showed their son Limitless. The film's core premise is that humans can only access 20% of their brains, and a drug allows them to unlock all of it. She was deeply unsettled: "You're teaching him wrong information."

She had to "detox" her child afterward: "That's not true, that's not how the brain works." Bradley Cooper's performance in the film is excellent, but scientifically wrong. Hollywood's creativity deserves respect, but its portrayal of the brain is far removed from real science.

What's Actually "Suppressed" Is the Subconscious, Not Idle Brain Regions

The brain operates in ways far more complex than "what percentage do you use." A vast amount of neural activity occurs below the level of consciousness—subconscious mechanisms constantly process information, we just don't notice. In certain creative states, activation levels in parts of the prefrontal cortex decrease, allowing normally suppressed subconscious mechanisms to surface.

This explains why inspiration often strikes during relaxation. But the storyteller emphasizes that this state can't be the norm: "If you're in that state all the time, that's not necessarily good either." What we need is the ability to "dive into" creative states and then "surface" back to everyday rationality—a flexible toggling in and out.

The Prefrontal Cortex and Creative States

The prefrontal cortex is located at the front of the frontal lobe and is responsible for executive functions including planning, decision-making, working memory, and impulse control. Neuroscience research has found that during creative tasks such as improvisation and divergent thinking, activation levels in parts of the prefrontal cortex (especially the dorsolateral prefrontal cortex) temporarily decrease—a phenomenon known as "frontal disinhibition" or "transient hypofrontality." This downregulation reduces top-down cognitive control, allowing associative networks to combine distant concepts more freely, thereby facilitating inspiration. But the prefrontal cortex doesn't shut down completely; it enters a more relaxed monitoring mode. Prolonged immersion in this state can lead to scattered attention and impulsive behavior, so the brain needs to switch flexibly between control and relaxation.

Why This Myth Persists

The enduring vitality of the "10% brain" myth lies precisely in its simplicity, its inspirational appeal, and its ease of packaging into a story. It implies that everyone harbors undiscovered genius—all you need is to find the "switch" to turn your life around. This narrative is hugely popular in commercial marketing and self-help content, yet it doesn't withstand scientific scrutiny.

What truly deserves attention isn't a fictional "unlocking" but understanding how the brain dynamically balances consciousness and subconsciousness. Creativity isn't achieved by "opening more brain regions"—it comes from training the brain to switch fluidly between different modes.

The next time you hear that "humans only use 10% of their brains," feel free to file it under science fiction, not scientific fact. Our brains are always running at full capacity—they don't need unlocking, just proper understanding.

One-line Summary

"Humans only use 10% of their brains" is a myth; the brain is always fully active, and creativity arises from flexibly switching between conscious and subconscious modes.

Paragraph Summary

The article debunks the popular myth that "humans only use 10% of their brains," pointing out that the brain is a high-energy organ, evolution wouldn't retain useless tissue, and modern brain imaging has never found silent regions. Hollywood films like Limitless offer creative "brain unlocking" premises that contradict neuroscience and can mislead the public. The real neural mechanism lies in the dynamic balance between consciousness and subconsciousness: during creative states, activation in parts of the prefrontal cortex decreases, allowing subconscious mechanisms to surface—but one must be able to switch flexibly rather than remain in that state. The myth persists because it is simple and inspirational; we should focus on how the brain fluidly switches between different modes, not on fictional "unlocking."