The brain is the most amazing organ in the human body. Somehow, this collection of billions of cells gives rise to thoughts, feelings, action — all the things that make us who we are.
So it's no wonder that there are lots of misconceptions about how this three-pound hunk of flesh actually works. Here are five of the biggest myths about the human brain:
1) Myth: Listening to Mozart makes you smarter
The myth that classical music — and specifically Mozart — can make people more intelligent has been going strong for 20 years. Back in 1998, the governor of Georgia even tried to fund a free classical tape or CD for every newborn baby in the state. But there's very little data suggesting that listening to Mozart actually makes you smarter.
The "Mozart effect" first became a public sensation after the prestigious journal Nature published a paper in 1993. That study, led by Frances Rauscher (now at the University of Wisconsin), found that college students who listened to Mozart's Sonata K.448 for 10 minutes ended up scoring roughly 8 points higher on spatial intelligence tests than those who listened to relaxation instructions or silence.
But even in this study, the effects were very temporary — wearing off after 10 to 15 minutes. And listening to Mozart only had effects on spatial intelligence tasks like folding paper or solving a maze with a pencil. (A follow-up study later found similar spatial improvements in rats exposed to Mozart in the womb.)
But in general, improvements in one area of intelligence are not thought to bleed over into other areas. So there's no reason to think that this would make anyone better at, say, math or verbal reasoning.
Dozens of studies have been performed examining the effects of classical music since then. Some have been able to replicate the small effect of the initial Nature study, and others haven't.
Some scientists think that the results had more to do with enjoyment and mood than the specific structural genius of Mozart. And experiments have found similar effects with other music, including a study in 2006 that found that the rock band Blur worked better for a group of 10- and 11-year-olds than Mozart did.
Even so, investigations on that one specific Mozart sonata still continue today — including recent studies that suggest some positive effects on the brainwave patterns of patients with epilepsy.
2) Myth: The right brain is creative. The left brain is logical.
The brain is separated into two hemispheres, connected by a structure called the corpus callosum. This arrangement has led to many conjectures about how each side is wildly different. But many of these conjectures are wrong.
A healthy brain works across both halves all the time using that connection. And contemporary brain-imaging technology such as fMRI makes it clear that the brain is very collaborative. Even simple tasks involving language, math, and creativity use areas across the entire brain and both of its hemispheres.
There is one major difference between the left and right hemispheres of the brain. The right-hand side of the brain controls the left-hand side of the body, and the left-hand side of the brain controls the right-hand side of the body.
Still, even that's not set in stone. If a person gets brain damage, healthy parts sometimes take over — even on the other side of the brain.
For example, surgeons have sometimes removed half of a child's brain to stop severe recurring seizures. Some children may lose movement on the opposite side of their bodies, but many are still able to normally walk and talk — and maintain their previous personalities, too.
(There are, however, some good reasons why the brain might be split in half to begin with — ways that lead to better function overall. NPR's Tania Lombrozo has an interesting interview all about that.)
3) Myth: You only use 10 percent of your brain
This myth is as widespread as it is wrong. And it's not fully clear where it came from. But its persistence may be because of wishful thinking — it's nice to believe that everyone has this amazing unlocked potential.
Now that researchers are able to actually observe brain activity using fMRI and other imaging techniques, they can clearly see that parts all over the brain get used for even simple tasks. "Evidence would show over a day you use 100 percent of the brain," John Henley, a neurologist at the Mayo Clinic explained in Scientific American.
This makes intuitive sense when you think about it. The brain is a hungry organ, using roughly 20 percent of your energy. It would be highly inefficient — and highly unlikely — for humans to have evolved such large, energy-hogging brains if they didn't need to use the whole thing. It would simply be a giant waste of resources.
4) Myth: Adults can't make new brain cells
In fairness, this one wasn't just a popular myth. For a long time, most scientists firmly believed that people stopped making new brain cells once they reached adulthood. They were so attached to this idea that when MIT researcher Joseph Altman found evidence in the 1960s that adult rats were producing new brain cells, other researchers didn't listen to him.
But then the evidence started piling up in other species. In the 1980s, scientists found evidence that adult songbirds produced new brain cells. Then in the 1990s, similar evidence emerged for mice and monkeys.
Finally, in 1998, scientists published a study showing that adult humans also make new brain cells. They determine this by injecting a cell marker into the brains of several volunteers with cancer. After these patients died, the researchers examined their brains and found solid evidence of new brain cells in the hippocampus, the structure that's key for memory.
Scientists are still figuring out exactly what these new cells do and how they might affect people's minds.
5) Myth: Your memories are accurate
Memories can be quite unreliable. And that's true for even highly emotional snapshots in time that seem exceptionally vivid (often called "flashbulb memories"). Our recollections are subject to errors, gaps, false suggestions, and approximations. Memories can also fade over time. The brain isn't a perfect computer-like data storage device, but a fallible fleshy organ.
For example, a study conducted after the highly dramatic OJ Simpson murder trial found that only half the memories of how people had heard the verdict were highly accurate after 15 months. After 32 months, only 29 percent were.
A similar study performed seven weeks after 9/11 found that 73 percent of Manhattan college students incorrectly remembered seeing footage of the first plane hitting the World Trade Center on the day of the attacks. But that was impossible. The footage didn't become public until September 12.
Some researchers, such as Karim Nader, believe that memories may be most susceptible to modification when they're actively recalled, according to Greg Miller's profile in Smithsonian. And this could mean that important memories, which people conjure up often, could end up even more error-riddled than mundane ones. They might stick around because you keep actively thinking about them, but get warped over time as they're rehearsed over and over again.