Quick quiz: Are you right-brained or left-brained?

© Atlassian

Leviathan Press:

The "two-mind hypothesis" mentioned in the article is very interesting. According to Julian Jaynes, the human brain has been in this split state until 3,000 years ago. The way they experience the outside world is not so much that they can consciously make assessments when encountering novel or unexpected situations, but rather they will have auditory hallucinations, or imagine that "God" gives advice or orders, and then unconditionally obey these hallucinations.

Quick quiz: Are you right-brained or left-brained?

You can probably answer this question quickly. If you are a creative and intuitive person who enjoys music, images, and other forms of art, then you are right-brained. On the other hand, if you are more analytical and logical, and enjoy math and pattern recognition, then you are left-brained. If you don't know which one you are yet, there are countless online tests to help you identify, strengthen, and maximize your inherent cognitive strengths.

In fact, the left-right brain theory has permeated all kinds of industries—particularly the business world, with many companies hiring right-brained employees for more creative roles and left-brained employees for management positions. Given its widespread acceptance and use, the theory must be based on the latest neuroscience, right?

Sorry, this view is not accurate.

Like the idea that we only use 10% of our brains, the left-brain/right-brain theory is a persistent pop-psychology myth—just as many personality tests, including the famous Myers-Briggs, are about as predictive as astrology. Like many modern science myths, though, the left-right brain dichotomy is based on a kernel of truth. Certain brain functions are indeed concentrated in different hemispheres, but this lateralization (the distribution of functions between the two hemispheres) is much more complicated than the simple model presented by pop psychology.

So how much of this modern myth is true, and how much is completely made up?

© Wikimedia Commons

From the outside, the brain appears to be perfectly symmetrical. At the bottom is the hindbrain, which is made up of two structures: the brainstem, which controls autonomic functions such as breathing and digestion, and the limbic system, which controls more complex basic functions such as memory processing, emotions, and motivation. Below the hindbrain is the cerebellum, which is responsible for sensory processing and motor coordination, and surrounding it is the forebrain, which is responsible for higher cognitive functions. The cerebrum is divided into two hemispheres along the midline, and each hemisphere is further divided into four lobes: frontal, parietal, temporal, and occipital. The cerebellum is also divided into two symmetrical hemispheres, and the cerebral hemispheres are connected to each other by a bundle of nerve fibers called the corpus callosum.

As early as the 1860s, though, evidence began to suggest that the brain was not as symmetrical as it appeared. In 1861, French physician and anatomist Paul Broca encountered two patients with significant speech impairments. The first patient, Louis Victor Leborgne, had almost completely lost the ability to speak, uttering only a single word: “temps” [pronounced “tan” or “tahn”]—French for “time.” Curiously, his other cognitive abilities—including the ability to read, write, and understand spoken language—were intact.

Leborgne's brain, deposited by Broca at the Dupuytren museum in Paris. © Neurosciences and History

A second patient, Lazare Lelong, had a similar disorder, and could only say five words: “yes,” “no,” “three,” “always,” and “lelo”—a mispronunciation of his last name. Broca performed autopsies on both patients’ brains after their deaths and found that both had suffered from neurosyphilis , which had caused damage to the same area of ​​their brains: the third gyrus in the left frontal lobe.

These findings led Broca to publish a landmark paper in 1865, “Localization of Speech in the Third Left Frontal Cultivation,”[1] in which he hypothesized that speech production was concentrated in this region, now known as Broca’s area.

A decade later, in 1874, the German physician and anatomist Karl Wernicke described a similar but different form of aphasia in which patients could speak fluently but spoke nonsense sentences lacking structure and meaning—what is known today as “word salad.” Curiously, these sentences retained the rhythm and syntax of normal speech, and patients were completely unaware that their language was disordered. Their ability to comprehend language, both spoken and written, was also typically impaired. Like Broca, Wernicke found that the impairment was caused by damage to a specific area of ​​the brain: a region in the left posterior frontal lobe now known as Wernicke’s area.

These observations led Wernicke to divide aphasia into two basic types: Broca's or motor aphasia , and Wernicke's receptive aphasia .

Broca and Wernicke's findings led psychologists to conclude that language production and comprehension were entirely concentrated in the left hemisphere of the brain. However, it wasn't until the 1960s that the extent of the brain's lateralization really began to be understood. In the early 1960s, neurosurgeons began performing a radical new surgery to help patients with severe epilepsy.

The surgery, called a corpus callosotomy , involves severing nerve fibers in the corpus callosum to prevent epileptic signals from being transmitted from one hemisphere to the other. Initially, it was thought that the surgery had no side effects, but as the patients were observed over time, their behavior became increasingly strange. They began to prefer using the right side of their bodies when performing daily tasks and seemed completely unaware of any stimulation on the left side. For example, if something touched their left arm, they would not notice; if an object was placed in their left hand, they would deny its presence.

Roger Sperry (1913-1994). © The Pontifical Academy of Sciences

Intrigued by this strange behavior, in 1962 Caltech neurophysiologist Roger Sperry and his graduate student Michael Gazzaniga began a series of groundbreaking experiments to try to understand what was going on in these split-brain patients. Their findings revolutionized our understanding of the human brain.

Although the corpus callosum had previously been thought to be a minor structure—psychologist Karl Lashley even speculated that its function was little more than “keeping the hemispheres from sagging”—Sperry and Gazzaniga soon discovered the important role it played in brain function.

Due to a quirk of vertebrate evolution, our nervous systems are cross-controlled, meaning each hemisphere receives information primarily from the opposite side of the body. For example, the optic nerves that carry visual information from our eyes to our occipital lobes cross at the optic chiasm, meaning information from the right eye goes to the left hemisphere and vice versa. Likewise, each hemisphere controls an opposite side of the body, so a stroke in the left hemisphere, for example, can result in paralysis on the right side of the body and vice versa. Normally, this seemingly counter-intuitive arrangement works just fine, as information is immediately passed through the corpus callosum to the correct hemisphere. But in split-brain patients, this communication channel no longer exists, meaning information sent to a specific hemisphere stays in that hemisphere. This is where things get weird.

Sperry and Gazzaniga probed patients’ hemispheric function separately by stimulating the opposite side of the body—for example, by presenting an image to the right eye to stimulate the left hemisphere. In one early experiment [2], they flashed a series of lights in a patient’s field of vision. When asked to report when they saw the lights, the patients only reported the lights on the right side. But when asked to indicate when they saw the lights, they successfully reported the lights on both sides.

© Knowing Neurons

Next, Sperry and Gazzaniga projected the word "HEART" so that the letters "HE" appeared in the patients' left visual field and the letters "ART" appeared in the right visual field. When asked to report what they saw, the patients responded verbally with "ART"; but when asked to point to the word they saw with their left hand, they pointed to "HE." Similarly, if an object was placed in the patients' right hand, they could easily name it, but when asked to point to an image of the same object with their right hand, they were unable to do so. When the side was reversed, the patients could easily point to the object but, confusingly, could not name it. These experiments confirmed that language processing abilities are almost entirely restricted to the left hemisphere, while the right hemisphere is specialized for visual perception tasks, such as recognizing faces and emotions and detecting differences between objects.

While these differences are puzzling enough, the experiences of patients living in a split-brain state are sometimes even more bizarre, with patients feeling that they actually have two separate brains—and that these brains often conflict with each other. For example, patients have reported that they button their clothes with one hand while the other hand spontaneously unbuttons them, or put items in a shopping cart with one hand while the other hand puts them back on the shelf. Many patients are even able to draw two different images simultaneously with both hands, but the left hand usually outperforms the right hand in this task due to the right hemisphere's advantage in spatial reasoning.

Alien Hand Syndrome in "Dr. Strangelove": The left and right brains fight each other, and the left hand can't control the right hand to make a Nazi salute. © Pinterest

In rare cases, the phenomenon can even manifest as "Alien hand syndrome," where one of the patient's hands seems to have a will of its own, sometimes even trying to strangle the patient or others. This phenomenon is also sometimes called "Dr. Strangelove Syndrome," named after the character of Peter Sellers in Stanley Kubrick's 1964 film, who exhibits similar symptoms. Unfortunately, there is no cure for the condition other than keeping the offending hand busy with other tasks or limiting its activity at night to prevent harm.

Sperry summarized his findings in a seminal 1974 paper that would eventually win him the 1981 Nobel Prize in Physiology or Medicine. He concluded:

“…[each hemisphere] is truly a separate conscious system that operates at a distinctively human level in terms of perception, thought, memory, reasoning, willing, and emotion…The left and right hemispheres can simultaneously be conscious of different, even contradictory, psychological experiences that proceed in parallel.”

In particular, Sperry concluded that the left hemisphere specializes in logic, sequencing, linear thinking, mathematics, hard facts, and literal thinking. In contrast, the right hemisphere handles "softer" tasks such as imagination, holistic thinking, intuition, visual-spatial processing, facial recognition, and interpreting nonverbal social cues.

In fact, according to Sperry's experiments, this lateralization of mathematical thinking is almost complete:

“…mathematical testing of the subhemispheric area by nonverbal output and by limiting sensory input to the left visual field or left hand showed that…subhemispheric computational ability was negligible. By manipulating marbles or sticks, observing flashing lights in the left visual field, and indicating with the left hand…[split-brain] patients could successfully match numbers or add a digit to a number less than 10, but they failed when asked to add or subtract two or more numbers and in the simplest operations of multiplication and division.”

Later, Sperry observed that the right hemisphere could actually perform addition operations smaller than 20—the only exception to the left hemisphere’s complete dominance over mathematical thinking.

© Vinmec

Subsequent observations seemed to confirm Sperry's findings, and neurologists concluded that primary acalculia , the inability to understand and perform mathematical operations, occurs only when the left parietal lobe of the brain is damaged.[3] In contrast, secondary acalculia, caused by damage to the right hemisphere, affects the brain's ability to receive mathematical information through the senses or to express it through language, but does not affect the brain's basic ability to understand and process this information.

Less invasive studies have further confirmed task lateralization. In 1973, Dr. Robert Ornstein and Dr. David Galin of the Langley Porter Neuropsychiatric Institute in San Francisco asked subjects to perform various cognitive tasks while an electroencephalogram (EEG) monitored activity in each hemisphere.[4] When asked to do mental arithmetic, think about writing a letter, or perform language exercises (such as listing verbs that begin with the letter R), the subjects’ left hemisphere produced fast brain waves that indicate attention and activity, while their right hemisphere produced low-frequency alpha waves that indicate relaxation, suggesting that the right hemisphere was essentially shut down during these tasks. However, when subjects were asked to complete a puzzle with colored blocks, remember the sequence of musical notes, or draw a picture using a sketchpad, the opposite was true, with the right hemisphere producing fast brain waves and the left hemisphere producing alpha waves.

Ornstein and Garin conclude:

"Our view is that in most everyday activities we simply alternate between different cognitive modes, rather than integrating them together. These modes complement each other, but they cannot replace each other."

However, despite Sperry's warning:

“… the idea of ​​an experimental polarity of right-left cognitive styles is very easy to generalize. ”

…but it was too late. In a 1973 article in The New York Times Magazine discussing Ornstein and Galin’s experiments[5], the two scientists suggested that different people’s talents and abilities are shaped by which side of their hemisphere is dominant:

"Ideally, we should be able to activate the right hemisphere and shut down the other hemisphere depending on the task. But in reality we can't always do that. 'Many people are dominated by one mode or the other,' Dr. Ornstein points out. 'They either have difficulty with crafts and physical movements or they have difficulty processing language.' Culture obviously has a big influence on this. Children from poor black communities often use their right hemisphere more - they score higher than white people on pattern recognition tests of incomplete figures, for example, but perform poorly on language tasks. Other children who have learned to verbalize everything find this approach a hindrance when it comes to imitating a tennis serve or learning dance steps. Analyzing these movements with words only slows them down and interferes with direct learning through the right hemisphere."

“We don’t have the flexibility we should have,” Ornstein says. “We imagine we have more control than we actually do.” Early in life, many people seem to be molded into being either “left-hemisphere types,” who operate primarily in a verbal world, or “right-hemisphere types,” who rely more on nonverbal expressions. These are two fundamentally different ways of looking at the world.”

The article further states:

"Drs. Ornstein and Garin believe that when habitual use of the same side of the brain becomes too pronounced, it can limit a person's personality. The two researchers are currently working on a test that might help them determine which side of the brain a person has a chronic preference for, and whether this habit prevents them from shifting dominance to the other side when necessary. They plan to test it on people who are truly specialized, such as Ralph Nader (a left-hemisphere type with no hobbies or interests), and on right-brain dominant ceramicists, dancers and sculptors ('preferably those who have difficulty with language'). They expect to find significant differences between the two groups. This will give them a tool to guide children or adults to discover new aspects of themselves and open them up to experience."

Thus was born a lasting pop psychology myth, with publications including Time magazine, Harvard Business Review, and Psychology Today soon jumping on the “left brain/right brain” bandwagon. The theory was further popularized by Betty Edwards’ 1979 book Drawing on the Right Side of the Brain.

In the book, the author proposed various techniques to help people bypass the "analytical" left brain so that visual creativity can flourish. Today, the left-brain/right-brain theory has spawned a plethora of online tests, seminars, and other materials designed to help people determine which side of the brain is dominant, maximize their potential, and even strengthen the non-dominant side of the brain. The idea has even seeped into the business world, with some companies trying to hire right-brained employees for more creative roles and left-brained employees for management positions.

But as is often the case when studying the human mind, things are not nearly as simple as pop psychology would have us believe.

© Cornell University

Although the findings of Sperry, Ornstein and others seemed to indicate that the right hemisphere played little role in mathematical thinking and language processing, this was not actually the case. Sperry observed that the right hemisphere also played an active role in so-called left-brain tasks. For example, when a patient saw a picture of his girlfriend through his left eye, he was able to spell her name using Scrabble letters, although he could not say her name.

They also found that while the left hemisphere excels at direct word associations, the right hemisphere is better at recognizing more subtle relationships and cues. For example, when the left hemisphere sees the word "foot," it's better at picking out related words like "heel" from a list of words. But when the right hemisphere sees two additional words, "cry" and "glass," it's more likely to pick out the connecting word -- in this case, "cut."

The right brain also plays a bigger role in mathematical thinking than expected. Kara Federmeier, a psychology professor at the University of Illinois, explains:

"To answer this question, first we have to agree on what we mean by 'logic' and 'creativity'. So let's consider a (relatively) more clear-cut example: mathematical ability, which is often thought of as the 'logical' left brain part.

There are many different kinds of maths ability, from being able to estimate which of two sets has more items, to counting, to various types of calculations. Research suggests that, in general, maths ability is shaped by processing in both hemispheres (specifically an area of ​​the brain in each hemisphere called the intraparietal sulcus), and that damage to either hemisphere leads to difficulties with maths ability. The left-brain advantage in maths is mainly seen in tasks like counting and memorising multiplication tables, which rely heavily on memorised verbal information (so not exactly what we normally think of as 'logical'!). There are also some maths-related tasks where the right brain has an advantage, particularly when estimating the number of objects. This pattern, with both sides of the brain making key contributions to most cognitive skills, is universal. To be logical or creative requires both hemispheres to work together.”

Indeed, based on popular belief about the left-brain/right-brain division of labor, we would expect those with right-brain damage to be cold and emotionless, but hyper-rational calculation and decision-making machines, like the Vulcans in Star Trek. In reality, however, these people have trouble making even basic decisions or plans because they lack the intuitive and emotional functions to envision the big picture and translate logic into practical action. Logic and emotion are not the opposites of each other that people often believe; both are necessary to function effectively in the real world.

Recent research[6] suggests that many cognitive functions are actually equally divided between the two hemispheres, including processing visual and auditory stimuli, spatial manipulation, facial recognition, artistic abilities, numerical estimation, and comparison. Even the left-sidedness of core language abilities identified by Broca, Wernicke, and others is not always correct.

For example, while Broca’s and Wernicke’s areas are usually located in the left hemisphere, they are located in the right hemisphere in 5% of right-handed people and 30% of left-handed people (remember, their dominant hand is controlled by the other hemisphere)[7]. In fact, the lateralization of different cognitive functions varies so much between individuals that neurosurgeons often perform special tests to pinpoint these cognitive locations before performing invasive brain surgeries such as tumor removal. This test is called intracarotid sodium pentobarbital, or the Wada-Milner test[8], and it involves injecting a barbiturate sedative into one hemisphere or the other to inactivate it and asking the patient to perform various cognitive tasks.

William's brain developed abnormally in the womb. After he was born on July 12, 2005, he suffered up to 80 seizures and convulsions a day, and his parents decided to undergo a radical hemispherectomy. Before the surgery, doctors warned him that the operation might make him unable to walk. But eight years later, the fourth grader can not only run, but also shoot and score. © Indianapolis Monthly

The common view of brain lateralization also fails to explain the phenomenon of “neuroplasticity” – the brain’s amazing ability to adapt to physical injury. Children who have had an entire hemisphere removed due to cancer or other illness can still lead completely normal lives, with the brain reorganizing to use the remaining hemisphere to perform all necessary functions.[9] This kind of neuroplasticity has also been observed, albeit to a lesser degree, in adults who have undergone similar surgery or who have sustained traumatic brain injury.

OK, so the brain is far more complex than pop culture would have us believe, and its functions are more evenly distributed than we expected. But surely different people would be biased towards using one side of the brain more? After all, how else would one explain that some people are more logical and analytical, while others are more creative and artistic?

Unfortunately, science doesn't support this idea.

In 2013, Jared Nielsen and colleagues at the University of Utah conducted a study[10] that analyzed the neural activity of 1,011 individuals aged 7 to 29 while they performed various cognitive tasks using a resting-state functional connectivity magnetic resonance imaging (RS-FCM-MRI) device. The study found that:

“Nine left-lateralized and 11 right-lateralized hubs were identified…[as] significantly lateralized connections. Left-lateralized hubs included regions in the default mode network…while right-lateralized hubs included regions in the attention control network…left-lateralized and right-lateralized hubs formed two separable sets of mutually lateralized regional networks. Connections involving only left-lateralized or only right-lateralized hubs showed positive correlations across subjects, but only for connections with shared nodes. Lateralization of brain connectivity appears to be a local rather than global brain network property, and our data are inconsistent with global brain phenotypes of more ‘left-brained’ or more ‘right-brained’ network strength across individuals. There was a small increase in lateralization with age, but no sex differences were observed…[We also found] that lateralized connections across individuals were independent of each other, and most functional lateralization occurred before the age of 7 years.”

In other words, while the localization of various cognitive functions varies between individuals, overall no one hemisphere dominates to a significant degree. In fact, many skills and talents come not from more work by one hemisphere but from more efficient collaboration between the two hemispheres. For example, children who are considered gifted in math or music often show better communication between the two hemispheres, allowing them to more effectively combine logical/analytical and creative/intuitive abilities. Conversely, those who struggle with certain tasks are not necessarily because one hemisphere is weaker but often because one hemisphere has developed to perform tasks normally handled by the other hemisphere. As with nearly all cognitive tasks, even the weakest skills can be gradually strengthened with practice.

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Despite over 50 years of research disproving this idea, an estimated 68% of people still believe in the left-brain/right-brain myth. Why is this?

The answer is simple: because we humans like to think about ourselves, and come up with all sorts of systems for dividing ourselves and others into neat categories.

Like horoscopes and many personality tests, tests designed to determine left- or right-brain dominance exploit a psychological phenomenon known as the Barnum effect — the tendency for people to believe descriptions that appear tailored specifically to them, but are in fact vague enough to apply to anyone.

This effect is often exploited by astrologers, psychics, and other scammers, the most famous example being James Randi, a stage magician and paranormal debunker who gave a group of students personalized horoscopes and asked them to rate the accuracy of the descriptions. Almost without exception, the students rated the horoscopes as highly accurate. Randi then asked the students to exchange horoscopes, at which point they discovered that they had all received the same exact content!

© Sam Brinson

The left-brain/right-brain fallacy provides a plausible explanation for our daily observation that some people seem more logical and analytical, while others are more creative and intuitive. It also allows us to make excuses for our own shortcomings: I'm not good at math, it's not my fault, you see, I was born right-brained ! But in reality, our cognitive skills are influenced by many factors, including genes, upbringing, mindset, and training and education - none of which can be simply attributed to "right-brained" or "left-brained."

Although the lateralization of cognitive function may not have a significant impact on our personality or innate skills, it still has a profound impact on how the brain works. For example, although the information received and processed by each hemisphere is usually shared with the other hemisphere via the corpus callosum, this sharing is not always possible. As psychologist La Federme explains:

“Processing within each hemisphere relies on a rich, dense network of connections. The corpus callosum that connects the two hemispheres is large for fiber bundles, but it is very small compared to the network of connections within each hemisphere. Therefore, it does not seem physically feasible for the two hemispheres to fully share information or to operate in a completely unified way. And, in many cases, it is actually smarter to have each hemisphere operate independently. It seems to be a good strategy for the brain to separate the tasks and allow the two hemispheres to work independently and process the same problem in different ways.

One of my favorite findings came from an experiment where we used adjectives to change the meaning of the same noun. For example, the word 'green book' refers to a concrete thing - that is, something that is easy to visualize in the mind. However, when given 'interesting book', people often think of the content of the book rather than its physical form, so the same word becomes more 'abstract'.

We wanted to see if concreteness differences would emerge for exactly the same words, and whether both hemispheres were equally affected by concreteness. In this experiment, we found that… the left hemisphere was very sensitive to the predictability of word combinations. There were far fewer nouns that could go with ‘green’ than with ‘interesting’, and brain activity reflected this when these words were presented to the left hemisphere first.

However, to our surprise, the right brain showed more image-related brain activity in response to the ‘green book’ compared to the ‘interesting book’. So while the left brain is clearly very important in language processing, the right brain may play a special role in creating the rich sensory experience that accompanies language comprehension … and what makes reading so pleasurable.”

In other words, even if our corpus callosum is intact, the brain can sometimes still behave like two separate entities—just like Sperry’s split-brain patients.

Even stranger is the fact that, until relatively recently in human history, this state of having 'two minds' may have been literally real.

The Collapse of the Bipartite Mind and the Origins of Consciousness is said to be one of David Bowie's favorite books. © The Bowie Book Club

In his 1976 book, The Origin of Consciousness in the Breakdown of the Bicameral Mind, Yale psychologist Julian Jaynes proposed that the normal human mind existed as a "bicameral mind" in the pre-Bronze Age of the Mediterranean, about 3,000 years ago. The two hemispheres operated as independent entities, with the "dominant" left brain generating ideas and communicating them to the "slave" right brain, which obeyed and executed these instructions.

© Science | HowStuffWorks

According to Jaynes, this split mind explains the ancient human notion of attributing thoughts and inspirations to the Muses or gods. Since they were unable to recognize that these thoughts were coming from inside their own brains, they would experience these thoughts as auditory hallucinations and attribute their origin to an external - often supernatural - source. This experience is similar to that of people with schizophrenia, who experience internally generated thoughts as auditory hallucinations.

In fact, schizophrenia, autism, and many mood disorders (including depression and bipolar disorder) are associated with significant changes in cognitive asymmetry.[11][12] For example, the left hemisphere is more associated with positive emotions, the right hemisphere is more associated with negative emotions, and people with depression often have excessive left-brain activity. Schizophrenia, on the other hand, is associated with reduced symmetry in activity between the two hemispheres.

© STLPR

Jaynes’ theory doesn’t mean that the human brain was ever physically split, though; the neural architecture of ancient humans was exactly the same as ours—including structures like the corpus callosum. Ancient humans’ mental schemas enabled them to react to situations, generate thoughts, and take action without the introspective ability to reflect on those thoughts and understand their internal origins.

In other words, humans lack meta-consciousness, or self-awareness. Jaynes argues that this psychological mode is a product of the simpler group living conditions of ancient humans, which did not require a self-reflective, unified mind to function. Only when people began to live in more complex societies, such as city-states, and began to develop writing, did the two halves of the brain begin to merge, forming the unified, self-reflective consciousness we know today.

Building on Jaynes’ theory, British psychopathologist and philosopher Iain McGilchrist went a step further, arguing that the brain’s unification and lateralization has become too skewed in one direction—and this has had a huge negative impact on modern Western society.

© CBC

In his 2009 book, The Master and His Emissary: ​​the Divided Brain and the Making of the Western World, McGilchist argues that not only do the two hemispheres function differently, they also see the world differently and promote different ethics and values. For example, the left brain tends to reduce complex, nuanced subjects, such as ethics, to simple rules and standards, while the right brain is able to more holistically see the world as an interconnected system. McGilchist notes that since the ancient Greeks, Western civilization has become increasingly dominated by left-brain thinking, which promotes a narrow, reductionist view of the universe that has led to many of our modern global problems.

Although Jaynes and McGilchist's ideas were influential and popular, they also attracted considerable criticism, with many neurologists, philosophers, and historians arguing that these theories, like the left-brain/right-brain pop psychology idea, oversimplify and distort the complex and subtle reality of brain lateralization and are based on unreliable historical evidence.

What is certain, however, is that, as the Scottish biologist JBS Haldane has argued, the human brain is not only stranger than we think, but is also likely stranger than we can imagine.

References:

[1]pubmed.ncbi.nlm.nih.gov/3530216/

[2]www.jstor.org/stable/24926082

[3]www.ncbi.nlm.nih.gov/pmc/articles/PMC6476153/

[4]www.sciencedirect.com/science/article/abs/pii/0028393274900529

[5]www.nytimes.com/1973/09/09/archives/we-are-leftbrained-or-rightbrained-two-astonishingly-different.html

[6]www.ncbi.nlm.nih.gov/pmc/articles/PMC8300231/

[7]www.nature.com/scitable/blog/student-voices/lefthand_man/

[8]www.ncbi.nlm.nih.gov/pmc/articles/PMC8117406/

[9]www.indianapolismonthly.com/longform/boy-with-half-brain-william-buttars/

[10]pubmed.ncbi.nlm.nih.gov/23967180/

[11]www.ncbi.nlm.nih.gov/pmc/articles/PMC10218831/

[12]www.ncbi.nlm.nih.gov/pmc/articles/PMC8931527/

By Gilles Messier

Translated by tim

Proofreading/tamiya2

Original text/www.todayifoundout.com/index.php/2024/09/are-people-actually-right-or-left-brained/

This article is based on the Creative Commons License (BY-NC) and is published by tim on Leviathan

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