Three major things most people get wrong about the brain, according to a neuroscientist

Yes, you use more than 10% of your brain — and no, being "right-" or "left-brained" isn't really a thing

By Troy Farah

Science & Health Editor

Published February 8, 2023 12:15PM (EST)

Futuristic human brain (Getty Images/imaginima)
Futuristic human brain (Getty Images/imaginima)

Squished between your ears, soaked in blood and swaddled in bone is your brain, a metabolic engine construed from roughly three pounds of fat and wired with electricity that, among other things, allows you to read and understand this sentence. Yet humans still have many fundamental questions about how this machine works, how it stirs consciousness into being and how to repair it when it breaks down.

Today, there's a greater interest in neuroscience than ever before, as companies like Neuralink promise to bridge the gap between brains and computers and as researchers inch closer to cracking neurological and psychiatric disorders like Alzheimer's, depression and addiction, all while so-called artificial intelligence slithers deeper into every crevice of the internet.

Yet, there's still a lot that people get fundamentally wrong about neuroscience. From the myth that humans only use 10 percent of their brain to the idea that creativity and logic is a "right-brained" versus "left-brained" issue, there are many popular misconceptions about neuroscience that have wormed their way into public consciousness. This isn't a benign problem, either — misinformation surrounding mental health can generate stigma, such as the belief that mental disorders are the result of weakness or lack of willpower.

But there's a good reason people get so much wrong about the brain. With an estimated 128 billion neurons, it's often said that the brain is "the most complex thing we have yet discovered in our universe."

"That's not untrue," Dr. Lisa Feldman Barrett, a neuroscientist, psychologist and author, told Salon with a chuckle. As a result, there's a lot of oversimplification, she says. The problem is especially egregious for some neurotransmitters — molecules or drug-like substances that relay signals between neurons. Dopamine or serotonin, for example, are neurotransmitters often reduced to being the "reward" or "happy" chemicals respectively, when they do so much more throughout the body (not just the brain) and their result is location specific.

"The power isn't in the chemical. It's in the chemical and the receptor," Feldman Barrett explains. It isn't easy to explain these complex relationships. In addition to regularly publishing cutting-edge neuroscience on emotion, psychology and more, Feldman Barrett is author of the 2020 book "Seven and a Half Lessons About the Brain," a book that tries to update and make modern neuroscience more accessible.

Here are three major things people get wrong about the brain:

Myth #1
The brain is region specific

Sometimes people will break it down into distinct geographies to better explain how the brain works. For example, the cerebral cortex is an outer layer of the brain that is responsible for functions such as memory, attention, and perception itself. But the boundaries between different regions is more nebulous than it might appear.


"Mental phenomena behavior are not localized to one little area of causation," Feldman Barrett explains. "There isn't a one-to-one mapping. The brain is functioning systemic wide. It doesn't work like a machine, where you can manipulate one little area and expect nothing else to be affected."


"The idea is that there are certain characteristics that are thought to be localized to specific regions of the brain," Feldman Barrett continues. "And that there's a one-to-one correspondence between the characteristic [or] behavior that you're observing or the feature that you're interested in and a location in the brain."


For example, the brain processes use to perceive an object, such as a tree, involves visual processing in the occipital lobe, one of the four major lobes of the cerebral cortex. Damaging the occipital lobe has been associated with hallucinations, misidentifying colors and difficulty reading.


But to fully perceive an object, the occipital lobe also pings other regions, especially the parietal lobe and temporal lobe, respectively responsible for sensory information (touch, temperature, etc.) and processing sensory information. It's through feedback of these systems that visual perception is possible. Every hub in the brain seems to serve some dual or multifaceted purpose.


The superior colliculus is a part of the brain often associated with visual processing. But some of Feldman Barrett's research, published ahead of peer-review, suggests that it also plays a role in processing many types of sensory information, including information related to a person's feelings and emotions.


"We need to be looking at the whole brain, not little swaths of it," Feldman Barrett says.

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Myth #2
You have a "reptile" brain

When scientists look at brains across animal species, they find many similarities and differences, especially when it comes to size and complexity. For a while, many neuroscientists believed that human brains could be split into three different segments: the reptilian brain, the paleomammalian brain, and the neomammalian brain. This is often called the "triune brain" theory, first postulated by neuroscientist Paul D. McLean and popularized by astronomer Carl Sagan. Unfortunately, it doesn't hold much weight these days.


It's true human brains are by far the most Gordian when it comes to the knots in our skulls, but evolution doesn't work like a line graph. That famous "March of Progress" image of monkeys slowly evolving into apes and then humans is not exactly how evolution works and has largely been debunked.


Human brains are not the apex of evolution — our cognitive complexity simply helped us stay alive long enough to pass down our genes. And just because our brains look similar to our predecessors does not mean they function the same. In fact, every time a new brain evolves, it almost completely reorganizes. And again, the brain cannot easily be divided into distinct segments.


A study published last September in the journal Neuroevolution provides clear evidence that mammals don't have reptile brains. Authored by researchers from the Max Planck Institute for Brain Research, the team compared central bearded dragon (Pogona vitticeps) brains with mouse brains. They profiled more than 280,000 cells, generating an "atlas" of over 230 distinct types of neurons. There were many similarities, but they weren't limited to location and contained a mix of the "old" and "new" neurons.


In other words, evolution keeps some things, shuffles others around and discards plenty. It's not accurate to same mammals have lizard brains stacked beneath the more recently evolved stuff. Tiny misconceptions like these can have big impacts. According to Feldman Barrett, the triune brain theory is simplistic, but the same lens has been applied to other aspects of the brain.


"That's not only the story of brain development, that's the story of mental illness," Feldman Barrett explains. "Mental illness is described as overactive emotion circuits and underactive cognitive control circuits. That's how almost every single mental illness is described." Both models are overly simplistic.

Myth #3
Brain damage is always permanent

Our brains may be special, but they are mostly soft, squishy bundles of fat, water, and various proteins and carbohydrates. Obviously, we need a rock-hard skull to protect all this precious matter, but sometimes our brains still get damaged.


One of the most prevalent myths of neuroscience is that this damage is inevitably permanent and irreversible. It's sort of related to the myth that the brain stops developing once you reach a certain age. Neither is true.


One of the principle tenets of neuroscience is Hebbian theory, which can be summarized as "Neurons that fire together, wire together." (Although not literally. The gaps between neurons — the synapses — are still critical.) Pathways in the brain that are used more frequently become stronger, like desire paths in the woods. The more a shortcut is taken, the sooner a weed-filled avenue becomes a path and then a road.


It may take additional "construction," but new roads can also be built in the brain, regardless of age. A baby is born with essentially a blank slate of neurons. As its brain ages, different centers solidify communication networks and build vast matrixes that give us complex ways of processing the world.


But the idea that once the brain reaches a certain age, these pathways are set in stone is wrong. If someone suffers a terrible brain injury in which important neurons die, the brain will sometimes find "detours" and continue functioning using undamaged neural highways.


This is called "neuroplasticity" and can be induced using certain therapies or drugs like psilocybin, although more research is needed in this area. Of course, it depends on many factors, including where the injury occurs and some brain damage is irreversible.


Overall, we should appreciate how complex our brains are and try not to simplify these concepts too much.


"Complexity empowers a brain to act flexibly in all kinds of situations," Feldman Barrett wrote in her book. "It opens a door so we can think abstractly, have a rich, spoken language, imagine a future very different from the present, and have the creativity and innovation to construct airplanes and suspension bridges and robot vacuum cleaners. Complexity also helps us contemplate the whole world beyond our immediate surroundings, even outer space, and care about the past and the future to an extent that other animals do not."


Humans are animals, of course, but what makes our brains special isn't so much the physical anatomy. It's the deep intricacy that makes us so different.

By Troy Farah

Troy Farah is a science and public health journalist whose reporting has appeared in Scientific American, STAT News, Undark, VICE, and others. He co-hosts the drug policy and science podcast Narcotica. His website is and can be found on Twitter at @filth_filler

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