This week is Brain Awareness Week, which includes a series of events undertaken by personnel at the Douglas and elsewhere to educate the public about the brain, and in honor of the occasion I thought I’d try to bring a modicum of brain awareness to my articles by dispelling some of the more common or insidious myths about the brain and its workings.
- We only use 10% of our brains
This one is a classic. There have been a number of proposed origins for this myth, including the idea that only 1/10th of your neurons are in a firing state at any point. I always assumed that the reason behind the myth was due to a misunderstanding about what percentage of the brain is involved in actual cognition, in that people confused the parts of the brain responsible for ‘cognition’ (ostensibly the prefrontal cortex in the context of the myth, but that’s debatable) with the proportion of the brain that is ‘used’. However, it looks like I may have been mistaken here. In any case, there is an incredible body of findings refuting this, not least of which is the entire field of functional neuroimaging.
- ‘Left’ and ‘right’ brain functions
Another extremely common myth. Although certain brain functions are usually lateralized (for example, language), for the most part the brain’s functions are represented in both hemispheres; and the idea that there are ‘left’ and ‘right’ brain people, who are more analytical or creative, respectively, is just not supported by neuroanatomy.
- No new neurons
I’m going to be talking more about this topic in a future entry, but for now let me just say that the doctrine that the brain stops producing new neurons in adulthood, as espoused by the great neuroscientist Santiago Ramon Y Cajal roughly a century ago, is false. We now know that adult brain neurogenesis does exist, from rodents to non-human primates to humans, especially in the hippocampus and olfactory bulb, and that these cells seem to be involved in a myriad of brain functions from learning and memory to emotional modulation.
- Mental illness is caused by…
In the past, our species has come up with an impressive array of explanations for the etiology of mental illness; in previous millennia and centuries (and in some parts of the world today) it was believed that demonic possession was the cause, whereas more recent theories have been much more varied. I’m particularly fond of this chart, which I’ve taken from Dr. Joe Rochford’s blog; in 1893, these were actual causes listed for the psychiatric conditions of Douglas patients, including disappointed affection, masturbation (cruelly, I fear the former could have led to the latter), tobacco abuse, menstrual irregularity, monotonous employment, ovarian irritation, religious excitement, sunstroke, and vicious indulgences. Thankfully, we have a bit more insight in our current age, and our theories on the etiology of psychiatric illness mostly center upon the idea that mental illness is caused by a combination of genetic predisposition and environmental stimuli, which affect brain functioning and cause cognitive, behavioural and emotional aberrations.
Phrenology, or the belief that certain bumps on the skull correspond to particular personality traits, originated in the late 18th century, was a big hit in the 19th, and in some cases is still around today. However, its methodology was often unscientific, and among neuroscientists today phrenology is dismissed as a pseudoscience. In its defence, though, I should point out that phrenology, though incorrect and outdated, did help advance neuroscience in two main areas: first, that it represented one of the earliest theories placing all mental activity within the brain; and second, that it led to the modern idea that different areas of the brain have particular functions.
- Anything at all to do with supernatural brain ‘powers’
I hesitate to even mention this point, as I’m sure it’s obvious to any rational reader, and because anyone who seriously believes they have magic brain powers won’t likely be convinced by this article. Nevertheless, I’m obligated to point out that telepathy, mind reading, astral projection, bearing witness to future events, et cetera are all mythical. It is true (and fortunate, for us) that the brain does perform some incredible feats to shape our experiences, but for better or for worse absolutely none of them are beyond the laws of physics.
- Retrograde amnesia is readily caused, and cured, by getting bonked on the head
The former may actually be true, but of course the latter isn’t. I only bother to point this out because, due to too many hours of cartoons, I think I probably believed this one as a kid.
- Listening to Mozart will make your kid smarter
It’s possible you remember a certain parenting craze of the last decade, wherein parents anxious about producing the smartest possible children would plunk their babies and infants in front of the TV to watch “Baby Einstein” and similar movies, in which classical music was played accompanied by baby-friendly visuals. The series became massive (in 2003, one in three babies in America had a Baby Einstein video), even earning praise from President George W. Bush during the 2007 State of the Union address. So what’s the problem? The videos don’t work, and may even be harmful; for example, a 2007 study on the effects of baby videos not only failed to find any benefit, but actually demonstrated a decrease in language abilities among infants who watched the videos, and in fact this detriment was worsened for every hour per day of baby video viewing. One of the authors of the study stated publicly regarding these videos that, “The evidence is mounting that they are of no value and may in fact be harmful. Given what we now know, I believe the onus is on the manufacturers to prove their claims that watching these programs can positively impact children’s cognitive development”. Although Disney (who by this point had purchased the rights to the Baby Einstein series) initially protested, by the end of 2009 the company changed their policy, and now offer refunds for Baby Einstein products.
That should do it for this Brain Awareness Week; regardless of whether you’re a member of the neuroscience community, I hope you get a chance to take part in the week’s events. Thanks again for reading, and feel free to leave any comments you might have.
16 Mar 2010