The brain is one colossally complicated piece of meat. A rough estimate by Johnston and Wu suggests that the human brain has 1012 neurons with 1015 synapses. Consider for a moment the magnitude of 1015 synapses: consuming a distance which is 222 times greater than the distance from Earth to Pluto. Each of these synapses carry important information through a very precise network of neuronal exchanges, constructing your unique experience through this world. A symphonic masterpiece of feelings, behaviors and experiences, as well as a warehouse of memory and awareness, it’s no surprise the brain is still a mystery to itself. So, what do we truly know about the brain? Better yet, what are we buying into that isn’t actually backed by fact? Let’s see what science says about the brain and throw out some old myths that keep us from truly knowing ourselves.
The Ten-Percent Myth
“The average person uses 10 percent of their brain capacity. Imagine what she could do with 100 percent.” So reads a poster for the action-thriller Lucy, starring Scarlett Johansson, a woman who inadvertently ingests a drug that taps into the remaining 90% of her brain. For scientists, the prevalence of this belief is puzzling. See this 2013 survey showing that almost two-thirds of Americans believe they are only using one-tenth of their brains on a daily basis.
The legend origin is unknown, but can be traced to psychologist William James who argued that, “we are making use of only a small part of our possible mental and physical resources.” Others say that Albert Einstein recognized his intellectual giftedness in the ability to use more than the typical capacity of his brain. Adding fuel to the mythos fire, Wilder Penfield’s “silent cortex” was discovered in the 1930s, suggesting that brain areas appeared to have no function when stimulated with electricity. Modern neuroscientific methods have proven that these “silent” areas are not as quiet as we once thought. Wherever it’s beginning, there is certainly no truth to the claim.
First, modern neuroimaging shows activity throughout the entire organ, even when at rest. This activity is less localized than scientists previously assumed. Further, even minor brain damage can have destructive effects—a surprising result if only one-tenth of the brain was utilized. Finally, brain areas that go unused because of disease or injury do one of two things. They either wither into nothing or degenerate, meaning the cells are colonized by brain areas in the neighborhood which make use of the weakened territory. Biologically speaking, unused brain tissue is not intended to be uninhabited for very long.
Most convincing of all, have you ever heard a doctor say, “Luckily the bullet only passed through the unused parts of your brain”? This one is a no brainer.
Left-brain vs. Right-brain
You’ve most likely come across an article or book with some step-by-step guide to unleashing the creativity of your right brain. Or maybe you know someone you’ve thought of as more “left-brain” judging by their calculated, analytical way of thinking. As with any myth, we can find a twinkle of truth here, but can we entirely delineate people into two groups: right-brain and left-brain thinkers?
This belief stems from brain function lateralization, the concept that the brain contains two hemispheres which each perform a number of roles. The two sides are separated by the medial longitudinal fissure and are connected via the bridge of the corpus callosum. Lateralization can be illustrated in muscle control, for example. When you are using your muscles on the left side of your body, there will be activity in your right hemisphere, and vice versa. This crossing of activity in the hemispheres also occurs during sensory perception. Even damage to one side of your brain will affect the opposite side of your body. However, these observations have been distorted to create the pop psychology notion of dichotomous right-brain and left-brain thinking.
Though there is hemispheric activity, neither the left nor the right side of the brain has a monopoly on one way of thinking. The left hemisphere, for example, specializes in processing auditory words in order to make meaning out of the syntax of the phrase, but is reliant on the right hemisphere to decode emotional features of language, such as in rhythmic intonation or tonal stress. “It’s absolutely true that some brain functions occur in one or the other side of the brain,” comments Jeff Anderson in his research on lateralization, “Language tends to be on the left, attention more on the right. But people don’t tend to have a stronger left- or right-sided brain network. It seems to be determined more connection by connection.”
Sex Differences Determine Social Outcome or Individual Success
Here, again, we can see how the beautiful complexity of the brain lends itself to misinterpretation and impulsive conclusions. Brains are different at birth and are ultimately responsible for driving impulses, values, and their very reality. But, can the conclusions we draw on these differences extend to dictate the outcome and overall success of these gendered brains in the world?
Changes in brain structure result from a delicate intertwining of biological and environmental influences. Some animal studies show that hormones, sex chromosomes and the immune system play a very important role in early sexual differentiation in the brain. In addition to this, gene expression, steroid hormones and early development stunting factors of prenatal and postnatal health and nutrition are factors that influence brain development.
This meta-analysis of sex differences in the brain provides a comprehensive look into sex differences on global brain volume and density, providing evidence of the developmental differences in the brains of males and females. Their findings state that on average, males have larger brain volumes than females. They also highlight regional sex differences in the amygdala, hippocampus and insula, areas typically implicated in various neuropsychiatric conditions associated with sex.
Even so, research on the topic is somewhat sparse, contrasting the confidence that many have in stating the source and outcome of gender differences. Cordelia Fine explains in her book Delusions of Gender: “There are sex differences in the brain. There are also large sex differences in who does what and who achieves what. It would make sense if these facts were connected in some way, and perhaps they are. But when we follow the trail of contemporary science we discover a surprising number of gaps, assumptions, inconsistencies, poor methodologies and leaps of faith.” Progress is being made in the field to understand the impact of neuroanotomical sex differentiation and its implications in society.
Ultimately, there are differences in the brains of male, female and otherwise specified individuals, though there is no conclusive evidence linking these biological differences to say, outcome in academics or occupation. This seems to be more directly shaped by cultural norms. All in all, brains are created equal, and each one is unique. There is nothing more frustrating than the type of reductionism that understands complicated social factors or markers of success as the direct result of gender.
Our Mental Capacity is Fixed
Another myth on the list is a belief that often coincides with biases toward people groups, and can be complicit in the segregation, minimization, and dehumanization of these groups. That is, many believe that our mental capacity is hereditary and cannot be changed by environment or experience. This is false. As we have discussed in the section on sex differences in the brain, mental abilities have something to do with genetics, but they are heavily influenced by environmental factors, and rely on adequate experience in order to develop. On top of this, our brains are adapting constantly, allowing us to learn, develop and add on to our mental inventory every day. Phenomena such as brain injury, stroke, mental health problems, learning disability or substance abuse can impede or stunt growth in the brain making it more difficult for the brain to learn and process information typically. Of course, none of these factors are based on inherent traits.
A Note on Neuroplasticity
The idea that our brains continually change been around since the late 19th century. At its simplest, neuroplasticity refers to the ability that neural systems have to mould or adapt. In general, the biology of the brain can be changed in a meaningful way by experience. Housing around 86 billion neurons, the brain’s dynamic capacity to learn and adapt is somewhat understated—it can be inconceivable when you stop to consider it. Neuroplasticity includes our capacity to learn and remember what we need and use, as well as our capacity to forget what we don’t. Plastic learning and adaptation occur at conscious and non-conscious levels, for example through intentional learning and implicit memory.
This implies the ongoing remodeling of brain structure and function, and occurs throughout life. The process can be affected by life experiences, genes, biological agents, and by behavior, as well as by thought patterns. Exercise and physical activity in general have a major effect on neurotrophic factors chemicals that stimulate the growth and recovery of brain cells.
Essentially, we are all capable of change. The implications this may have for mental health problems is hopeful, through cognitive restructuring. Understanding the phenomena of plasticity in the human brain dissolves the hopelessness that arises from a belief in mental rigidity.
Have You been Hoodwinked?
If you assumed that any of the above beliefs were true, you are not alone. One 2017 study by Mcdonald et al. reveals that the general public endorses 68% of neuromyths, educators believing 56%, and most shockingly, respondents with a background in neuroscience believing 46%. Even though exposure to neuroscience is more predictive of disbelief in neuromyth, it doesn’t entirely eliminate the problem.
To top it off, some information backed by brain-related research may be perpetuating brain myths. In her TED Talk, Molly Crockett describes how slapping a brain image or brain-related term on marketing and product brands provides unfounded credibility and can convince us of things we don’t fully understand.
In the age of fake news, it is important to develop a critical mind and stay on top of the facts. Where can we turn for relevant, empirical information about the mind and brain? In addition to Brainy Sundays, click these blogs for a deeper understanding of topics in neurophilosophy, health and science, psychology, and other info sites such as All in the Mind, Mental Elf, The Best Brain Possible, or The Dana Foundation.