BRAIN MYTH BUSTERS
For such a vital organ, we know very little about the brain – and false myths about its function are often widely accepted as fact. Now, new research is revealing more about how it really operates.
New research into the brain is revealing more about how the organ really operates.
For years, a myth has persisted that our brains are split down the middle, with a division of labour as finite as any union agreement. Our left hemisphere is the logical half, supposedly, and the right hemisphere houses creativity.
But this isn’t actually supported by evidence. Rather, it comes from an outdated understanding of the brain. New imaging technology has expanded scientists’ ability to study the brain’s structure and function. And although brain research is in relative infancy, researchers are learning more about this fascinating organ – including how sophisticated networks allow for widespread communication.
Their findings offer hope for managing brain disorders. With one in five Australians aged 16-85 experiencing a mental illness in any year, according to Black Dog Institute; and 2018 statistics from the Australian Institute of Health and Welfare showing that dementia was the leading cause of death for Australian women in 2016, answers can’t come soon enough.
The brain has two mirror-image halves (hemispheres) connected by what’s called the corpus callosum, “which is … an incredible speed
highway of information transport,” explains Professor Cassandra Szoeke – a neurodegenerative disease expert from the University of Melbourne.
BUSTING BRAIN MYTHS
Szoeke explains that neuroscientists don’t talk about the brain having left and right halves. Instead, they speak of the ‘dominant’ and ‘non-dominant’ hemispheres (or lobes). For righthanded people, their dominant lobe is the left, and for left-handed people, their dominant lobe is also often the left – but may be the right, she says.
Dr Steve Kassem, a postdoctoral fellow at Neuroscience Research Australia, points out that both sides of the brain are the same, “anatomically, chemically and cellularly”. What really spawned the left/right brain myth was the discovery of Broca’s area (the region of the brain responsible for forming speech and understanding language) in 1861 by surgeon Pierre Paul Broca. It is located in the frontal lobe in the dominant hemisphere, usually the left.
“It is this element of difference that propagated the idea that the left must be creative, and the right – by matter of subtraction – the logical, mathematical,” he says. “However, this isn’t always the case. My mother had a stroke in her Broca’s area and is still able to speak and comprehend because she was lucky enough to have another one on the other side.”
Dr Jared Cooney Horvath, an educational neuroscientist from the University of Melbourne, says that skills and functions are integrated across the whole brain. “This means there is no ‘reading’ part of the brain or ‘maths’ part of the brain. These functions are an amalgamation of many networks that must coordinate and interact to function.”
To read, for example, you need to move your eyes, vocalise words, hold sentences in memory and understand meaning. “When skills require many sub-skills, they necessarily require the whole brain to synchronise. Logic and creativity are some of the largest skills we know. As such, they’re not confined to one spot, but require coordination across the whole brain,” he says.
THE EVOLUTION OF IMAGING
Dr Horvath adds that, “To confound matters, with plasticity [the ability of the brain to rewire itself], we know of many people who do not have a left or right hemisphere – yet they’re as logical and creative as anyone else.”
Under some circumstances, the brain is sufficiently plastic to let areas swap functions, says Professor Susan Hillier, a researcher in neuroscience and rehabilitation at the University of South Australia. For example, people who are blind from birth can use the brain area that processes visual input to ‘see’ braille by touch.
Hillier says that brain research is driven by technology. “Each time we get better imaging, we get more and more information about what underlies these complex functions,” she says.
“Ten years ago, we were imaging brain regions, so everyone thought it’s brain regions that dominate. Now that we can image communication between brain regions, we’re starting to think … function maybe has more to do with the connectivity and communication between brain regions.”
Professor Szoeke points out that science is well behind in studying the brain, compared to other organs. As the skull stops the brain being seen on X-rays, CT scans were the first to show any brain images, she says. Next came MRIs, though the early ones were “so grainy it was really hard to see all the areas”. It’s only recently that functional MRIs and nuclear medicine scans have enabled the imaging of brain function.
Furthermore, tests have traditionally been used to understand dysfunction, whereas recent interest in optimising cognitive function and brain health has led to greater focus on “how [the brain] works rather than how it doesn’t work,” Szoeke says.
SMART CONVERSATIONS
Dr Horvath explains there are at least three ways in which brain regions talk. The first is by ‘neuronal communication’ – where cells pass on chemical messages to other brain cells and cause them to ‘fire’. “Put simply, we can imagine brain cells as small electrical wires passing messages throughout the brain – much like small telephone wires,” he says.
The second is via ‘gap junctions’. “Thought to be a myth for quite some time, it turns out brain cells don’t need to eject chemicals to speak. They can ‘steal’ signals from other brain cells … this would be like someone tapping into a phone line, stealing the signal as it passes across the wire.”
The final and “most cool” is called ‘ephaptic coupling’. “Although no-one yet truly understands the mechanism, essentially this form of communication allows large swathes of the brain to pass messages to other large swathes – likely via magnetic and/or electrical fields,” he explains. “This is like when you’re at a ball game, and half the stadium shouts ‘Let’s go…’, which then triggers the other half of the stadium to shout ‘Steelers’. There’s no direct passing of a chemical or an electrical message in this instance – but the global activity of one region can drive another region to ‘synchronise’ and act in accordance.
“Ephaptic coupling allows for entire networks to … communicate with entire other networks. Taken to its extreme, ephaptic coupling suggests the way we discuss and understand brain function is largely wrong … or, at least, wildly incomplete.”
Professor Hillier emphasises that the brain is exceptional at networking. “Even if an area has a speciality, that speciality is only realised through expansive networking with other parts of the brain,” she says.
One aspect of creativity, for example, is believed to be divergent thinking – or the ability to generate many different ideas about a topic. Hillier explains that people who are good divergent thinkers seem to have greater connectivity between brain regions. She adds that other highly networked functions include pain, emotions and memories.
“We know less than one per cent about what we need to know in order to solve the brain.”
DR JARED COONEY HORVATH
“There is no ‘pain centre’. Pain is constructed by a series of structures in the brain communicating with each other and creating an internal picture or representation of pain. It’s the same with emotions and memories.
“The brain is not a set of sole traders, and interestingly there is no boss,” she adds. “There is no control centre. It is very democratic.”
The importance of connectivity has implications across many areas, Hillier explains. For example, developmental coordination disorder – which affects children’s motor skills – may be related to a lack of connectivity. She adds that something similar may be happening with autism spectrum disorder. Social functions involve picking up social cues. and “having that cognitive resonance about what I’m seeing and hearing in other people and interpreting it”.
Somebody with autism, for example, might hear your tone of voice and see the frown lines on your face, but be unable to put those pieces together to understand that you are angry at them – due to an issue with connectivity.
FUTURE THINKING
Dr Horvath notes that understanding how the brain communicates is driving pharmaceutical treatments. “At the chemical level, basic communication suggests adding, replacing, or removing certain chemicals should change communication within the brain.”
Moreover, electric and magnetic communication can be manipulated through electric currents and magnetic fields. He says, “Herein lies the birth of electroshock therapy, transcranial magnetic stimulation, and other tools meant to bypass chemicals and trigger the brain signals themselves.
“However – although effective in certain circumstances – nothing is yet fail-proof or even highly predictable. We simply don’t know who will and will not respond to different treatments.”
Dr Horvath adds that emerging techniques are exploring ways to help people monitor – and learn to change – their brain activity, without needing any external chemicals or stimulation. “It is an internal control of a seemingly chaotic, uncontrollable system. This is where techniques like meditation and regulation drive change.
“Think about the implications: the ‘mind’ – an ethereal entity that arises due to brain activity (in conjunction with other bodily systems) – can actually [offer] feedback on and change the very brain activity that plays a role in its emergence. And not just random change – a completely focused and intentional change.
“This is akin to a black-and-white photograph somehow feeding back upon and changing the camera that took it, in order to change itself into a colour photograph.”
MORE TO LEARN
Dr Horvath notes that any neuroscientist will tell you we’re not even close to understanding how the brain really operates. “When we say we know less than one per cent about what we need to know in order to solve the brain, we’re not being flippant.
“There’s a saying in science: ‘That’s not even wrong’. We typically reserve this phrase for weird conjectures or theories that are so outlandish that to call them wrong would be lending them a credence they don’t deserve. There is every chance, in a century, neuroscientists will look back on our work and say, ‘That’s not even wrong’.”
Dr Kassem adds that we know more about the creation of the universe than we do about the brain’s processes. New research is uncovering information ranging from how genes within brain cells work, to whole new brain areas.
Still, myths about the brain persist because it is so mysterious. “It is the enigmatic organ that allows us to see, hear and speak – but more abstractly allows us to be creative, depressed, inspired and awed,” Dr Kassem says. “It even allows us to invent imaginary numbers to do mathematics on matter that doesn’t even exist.
“Just as there were myths about Apollo pulling the sun across the sky, there are myths [on the brain] because it is unknown. But with research, we get to investigate and explore the brain, discovering things about it. Hopefully, as astronomers did with the sun and Apollo, neuroscientists can [work out] the brain and its myths.”