Brain myths: Real and imagined

Myth No. 1: We only use 10 percent of our brain.

Here's the truth: Brain imaging studies using PET scans and functional MRI show that any mentally complex activity uses many areas of the brain, and over a day, just about all of the brain gets a workout. More proof that the entire brain is crucial for daily life is the devastating impact of damage to even a small area of the brain.

However, we do have some brain reserves. An autopsy study found that seniors who stay mentally active through activities like reading the paper, going to the theater, or playing chess—are less likely to develop Alzheimer’s disease—even if they have the characteristic physical brain changes typical of dementia, suggesting that mental function has a “use it or lose it” component.

That allows people who keep their brain stimulated to develop more brain reserves, allowing them to continue functioning normally even as their brains are being damaged by Alzheimer’s.

Myth #2: People are right-brained or left-brained.

The Truth: You’ve probably heard that left-brained people are logical and good at solving problems, while right-brained people are imaginative and artsy. This myth began in the 1800s, where doctors discovered that injury to one side of the brain frequently caused loss of specific abilities.

Brain scan experiments, however, show that the two halves of the brain are much more intricately linked than was originally thought, so problem-solving or creative tasks fire up activity in regions of both hemispheres of the brain, not just half.

It is true that the right side of the brain controls the left side of the body and vice versa, so a right-brain injury can cause disability on the left side of the body.

Myth #3: Your brain is gray.

The truth: You’ve probably seen preserved brains on TV or in a science classroom that look gray or yellowish white. Although the living brain is sometimes described as “gray matter,” it also contains “white matter” (nerve cells that link the gray matter), red areas (due to many blood vessels that feed the brain), and a black area colored by neuromelanin, a form of the pigment also found in skin and hair.

Preserved brains turn solid gray because they’re soaked in chemicals like formaldehyde.

Myth #4: “Flashbulb memories” are like photocopies of events.

The truth: We all have vivid memories of dramatic events, such as being in a car accident or what we were doing when the Twin Towers fell. But while these recollections may feel extremely precise, studies show that they can be surprisingly inaccurate because our mind can play tricks on us, Smithsonian Magazine reports. For example, one study found that 73 percent of college students “remember” watching TV coverage of the first plane hitting the north tower on 9/11. In reality, the south tower was hit first.

Myth #5: Our brains are less sharp after 40.

The truth: Actually, mental agility starts to slip when we’re in our late 20s, according to a study published in Neurobiology of Aging. When the researchers tested 2,000 healthy adults, they found that brain speed and reasoning skills (as measured by tests that involve solving puzzles, recalling words and story details, and spotting patterns) peak at age 22, then slowly decline, starting at age 27. However, some mental skills improve with age.

Older people have larger vocabularies, are better judges of character, and score higher on tests of social skills, such as how to resolve a dispute. They also out-perform the young on remembering images and phrases that evoke positive emotions, which may explain why surveys show that, on average, older people are happier.

NSBNews.net is Florida's first fully-online 24/7 Internet newspaper launched April 7, 2008, and based in New Smyrna Beach. It is led by award-winning journalist Henry Frederick and award-winning blogger Peter Mallory with emphasis on breaking news, news of record and investigative reporting here and across the Sunshine State.

Wendel Bradford