Brain Busters
Ally Thayer
Illustrations by: Sophie Sieckmann
In 2013, the Obama Administration launched the BRAIN Initiative: a research effort aimed towards understanding how the human brain functions. When he spoke at its unveiling, President Obama pointed out the largest paradox of neuroscience: “As humans, we can identify galaxies light-years away and we can study particles smaller than an atom, but we still haven’t unlocked the mystery of the 3 pounds of matter that sits between our ears.”
This “mystery,” otherwise known as the brain, has intrigued humanity for millenia, as human beings have always possessed an innate curiosity and desire to understand ourselves. Many fields, such as philosophy, sociology, psychology and anthropology, have stemmed from this fascination, attempting to answer the fundamental questions of what makes us human. Neuroscience addresses these questions head on, investigating the human mind by exploring neural connections in the brain. Generally, neuroscience strives to answer: What is consciousness? How do we experience dreams and emotions? What neural factors are involved in cognition? None of these questions have a simple answer; hence, our ever-present interest in the workings of the mind.
This innate human curiosity has also led to the ever-increasing prominence of neuroscience in pop culture and movies. However, filmmakers often inaccurately represent the science behind different neural phenomena. For example, the movie 50 First Dates (2004) tells the story of a woman who suffers from “Goldfield’s syndrome” after an accident. Each day her memory completely resets. Goldfield’s Syndrome is a fictional condition, but it is loosely based on a combination of several real types of memory loss. The critically acclaimed film Inception (2010) is also, neurologically speaking, inaccurate. The central premise of the movie is that while one sleeps, the dreamer can access several parallel realities and travel to other people’s dreams. Although fascinating, the events are not based on factual science. Film portrayals of complex neuroscience topics, such as dreams and memory have changed, disregarded, and even fabricated science. Because most viewers of these hit films do not have neuroscience backgrounds, they may be more inclined to believe this scientific misinformation. As a result, oversimplifications of complex neurological phenomena evolve into commonly believed myths that are eventually regarded as facts. In order to distinguish fact from fiction, I surveyed the neuroscience faculty at Vassar College, asking which popular neuroscience myths frustrate them the most. Here are the most common answers:
MYTH ONE: “We Only Use 10% Of Our Brain.”
The idea that we don’t utilize our full brains is one of the most commonly believed neuroscience myths. Several surveys have demonstrated that 65% of Americans, 1 in 3 people with a bachelor’s degree in psychology, and more than 1 in 20 neuroscientists agree with this claim [12, 10, 9]. The idea still lingers in modern-day pop culture, as movies like Lucy (2014), Defending Your Life (1991), and Limitless (2011) use plotlines emphasizing the “untapped superpower” residing in the supposed remaining 90% of the brain. However, despite how common this belief is, it is entirely false.
Many trace this myth back to Albert Einstein and William James, often referred to as the father of American psychology. Einstein has been misquoted as arguing that his above-average intelligence resulted from the ability to use more of his brain. In reality, though, Einstein never said this; but, it is very common to see quotes misattributed to him. Einstein’s brain was extensively studied after his death and it was actually found to be smaller than average;, however, he was reported to have higher-than-average numbers of a specific type of brain cell called glia [8]. William James did propose a theory that most of our brain and cognitive potential goes untapped; however, he never specified a percentage of brain use [11]. So, how did this myth get linked to James? Dale Carnegie’s best-selling book, How to Win Friends and Influence People, includes a misinterpretation of James’ work and implies we do not use all of our brain power [6]. This book was one of the first self-help books written and is considered by TIME magazine to be the 19th most influential nonfiction book written in English since 1923, meaning that many readers of Carnegie’s work likely took his misrepresentation of James’ theory as fact [18].
This myth may have also come from a misinterpretation of neurological research in the early twentieth century regarding glial cells. Glial cells are one of the two main cell types within the brain, lesser known to the general public than the other main cell type: neurons. While neurons fire to transmit neural information, glial cells act as the brain’s structural support, protecting and nourishing neurons. Several studies from the 1960s to the 2000s report a 10:1 glia-to-neuron ratio in the brain [19]. Because glial cells were thought to have no neural utility, researchers inferred that only 10% of the cells in the brain had a function. Thus, the idea that we only use 10% of our brain was born.
Neuroscientist Dr. Barry Beyerstein has provided several pieces of evidence to dispute this myth. First, Beyerstein reasons that if it were true that only 10% of the brain was in use, most neural damage would have no impact on normal functioning [5]. If 90% of the brain is inactive, most brain injuries would miss essential brain tissue and there would be no adverse effects. However, damage to virtually any part of the brain may cause personality changes, paralysis, sensory dysfunction, or the loss of language abilities. Brain imaging such as PET and fMRI (functional MRI) scans also show neural activity in all brain regions, no matter what the individual is doing [5]. This means that whether you are meditating, sleeping, or taking an exam, your brain is fully engaged. Finally, Beyerstein also makes an efficiency argument, explaining that the human brain spends 20% of the body’s total energy despite making up only 2% of the human body weight. If only a tenth of the brain is in use, devoting this much energy to the body part would be wasteful, and natural selection would have eliminated this inefficiency over the course of human evolution [5].
MYTH TWO: “Dopamine Makes Us Happy”
The media often refers to dopamine as the “feel-good chemical.” However, happiness is a complex emotion and neurological topic, and there is no single chemical or brain region responsible for one’s happiness. Dopamine is a neurotransmitter, or a specialized chemical that allows two neurons to communicate. Two communicating neurons do not physically touch one another; rather, a small space, called the synaptic cleft, separates them. When one neuron is activated, it releases a neurotransmitter into the synaptic cleft. This neurotransmitter makes its way to the second neuron to activate it, and the message is passed along.
The “feel-good chemical” myth arose from a 1950s study in rats by Dr. James Olds. Olds studied neurons that communicated via dopamine in rat brains; when these dopamine-releasing neurons were stimulated, Olds found that the rats were prompted to repeat the same activity over and over again, and he concluded that this repetition was due to the rats enjoying the activity [15]. It is also well known in the psychiatric community that individuals with depression have lower levels of dopamine and therefore, it is logical to connect dopamine to lower mood [3]. These theories have been disproven because animals still experience pleasure even if their dopamine neurons are killed [4]. In the late 1980s, Dr. Kent Berridge eliminated the dopamine neurons in rat brains and tested their responses to a sugar solution. He discovered that these rats, despite not having dopamine neurons, still showed signs of enjoyment and pleasure similar to the rats who had intact dopamine neurons [4].
If dopamine is not responsible for happiness, then what exactly is its role in the brain? Today, dopamine is thought to be involved in motivational behaviors [1, 7]. Because motivation can appear similar to pleasure and happiness, it can be easy to confuse them. But neurons that use dopamine aren’t actually telling us that we like performing an activity or task; rather, they are communicating that we should do or pursue that activity again. This is essentially the difference between wanting something and liking something, and it is especially clear in individuals with depression. Depressed people are often less likely to pursue social interactions, but this is not because they do not enjoy the company of others. In fact, they might still appreciate time with friends, but the effort needed to engage in social situations might prevent them from joining in. Similarly, people and animals with low levels of dopamine are less likely to work for a reward. Therefore, this behavior is more of an internal debate on how to spend one’s time and energy than a reflection of personal enjoyment.
Interestingly, dopamine also plays a large role in drug addiction, as many addictive drugs cause dopamine levels in the brain to increase by promoting more dopamine release from neurons [20]. You may have heard the term “dopamine rush” and associated it with a rush of happiness. However, a dopamine rush is actually a rapid increase in dopamine that instructs your brain to seek out whatever caused the surge more frequently, motivating the brain to overcome boundaries to access the source of the rush. In the case of drugs, the powerful motivational force of an extreme dopamine rush can compel a person to pursue a substance no matter how serious the obstacles and consequences are . For some, this can mean life or death — especially those most vulnerable to developing substance use disorders or addictive behavior patterns. So, no: dopamine may motivate us, but it certainly does not always make us happy.
MYTH THREE: “Right vs. Left-Brained People”
Another common neuroscience myth exists in the classification of people as either left-brained and right-brained. This idea is based on the brain’s two hemispheres and posits that people who think more logically, linearly, and sequentially (often excelling in science and math) have a dominant left hemisphere, while people who think more visually, imaginatively, and holistically (often excelling in the arts) have a dominant right hemisphere.
This myth originated from the work of neurologist Dr. Roger Sperry, winner of the 1982 Nobel Prize in Physiology or Medicine for research on the brain’s two hemispheres [17]. Sperry aimed to investigate the role of the corpus callosum, the bundle of neurons that connects the two hemispheres of the brain. Because surgery cutting the corpus callosum was one of the earliest treatments for epilepsy, Sperry studied the abilities of patients who had undergone this procedure and pioneered studying the functional differences between brain hemispheres. In his experiments, Sperry would present a word to either the participant’s left or right eye for only a moment and then would ask them what they saw [17]. At the time, Sperry knew that the right hemisphere of the brain exclusively responded to the image seen in the left eye, and vice versa. When he placed the word in front of individuals’ right eye, they were able to tell him what word they saw. However, when the word was presented to their left eye, participants could not tell Sperry what they saw. From this, Sperry concluded that the left brain is necessary for language articulation and understanding. Next, he asked the same participants to draw the word that was presented only to their left eye with their left hand, knowing that, similar to visual control, muscular control is also governed by the opposite brain hemisphere. These individuals were able to draw the word and recognize their drawing as a word but could not say it aloud. Sperry concluded that the right hemisphere can identify words as shapes, but can not articulate them. This contributed to the false notion that the combination of the two hemispheres is necessary for normal language functioning.
This study provides evidence for differences in hemispheres, and, therefore, evidence for the right-brained left-brained myth, right? There is no dispute that there is functional lateralization within the brain; the two hemispheres are not identical, and there are functions that one primarily holds over the other. For example, the majority of language processing is governed by the left hemisphere, as Sperry suggested [13]. The left hemisphere is home to the brain regions Broca’s area and Wernicke’s area, which are responsible for language production and comprehension, respectively. This myth, however, incorrectly conflates the idea of functional differences with personality. Human beings love to classify each other into personality groups, as shown by the Myers-Briggs personality test, astrological signs, and Hogwarts houses. While yes, everyone’s brain has functional differences that vary by hemisphere, these differences are not necessarily related to personality. A 2013 study investigated whether or not brain activity in each hemisphere differs from person to person, looking at just over 1,000 individuals and analyzing over 7,200 cortical regions via fMRI. The results showed some variability in brain activity by region, but those differences were consistent across all individuals [14]. The researchers found no separation of the cohort into “left-brained” and “right-brained” individuals, thus disproving the common myth.
So what could explain individual differences in creative and logical thinking capabilities? In 2018, a group of researchers sought out to answer this question by using fMRI data to observe connectivity between brain regions of study participants after they had completed creative thinking tasks [2]. The study found that connectivity patterns and creativity scores were so strongly correlated that they could predict the creativity of a participant’s response by looking at their brain scan. They concluded that a person’s creative ability is based on the connectivity of three prominent brain networks: the default, salience, and executive networks. The default network includes regions in the cortex, the cerebellum, and striatum, which are best known for roles in thinking, balance, and movement respectively. These regions are activated when people are brainstorming or imagining. The executive network resides primarily in the frontal cortex and is responsible for evaluating if the brainstormed idea will actually work. Finally, the salience network is composed of the cingulate cortex and insula, which are brain regions necessary for emotion regulation, maintaining homeostasis, and switching between the two other networks.
In other words, the default network puts the mind into dreamer mode, the executive network puts the mind into realist mode, and the salience network mediates when each mode is necessary. Interestingly, while these three networks are rarely all activated at the same time, this study suggests the more creative a person is, the better able they are to co-activate the networks [2]. These results are also consistent with another fMRI study of jazz musicians as they improvise melodies [16]. If you are trying to understand why, neurologically speaking, one person is more creative than another, resist the urge to categorize people into left and right brained individuals. As with every topic in neuroscience, the true explanations are very complex.
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Billions of brain cells work together to govern the human body and construct the human mind. One can devote their entire life to studying the brain and only scratch the surface of its inner workings. Every brain region has subregions. Every subregion has several different types of cells. Each of these cells have multiple, unique functions, which can also vary based on the types of cells that surround them. It’s easy to see why neuroscience can be so complicated to understand. Even neuroscientists find themselves subspecializing within the field because it is impossible to study it all. When neuroscientific findings are published, they can be difficult to interpret, even by someone with a science background; therefore, misinterpretations are inevitable. These misinterpretations manifest in popular culture as facts even if there is no intent to mislead society. When we are confronted with a neurological phenomenon in our daily lives, it is important that we question its scientific accuracy before blindly accepting it as true.
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