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- Part 1: Left brain vs right brain: We do have two hemispheres, but the popular description is misleading and sometimes simply wrong.
- Part 2: We use 10% of our brain: We always use 100% of the brain!
- Part 3: Learning styles: What sounds intuitively true is fundamentally wrong!
- Part 4: The Truth About Brain Development
We’ll start this series of posts on brain myths for teacherson the left brain / right brain myth which is a fascinating one to look at. The myth states that the left brain is the logical, rational, reasoning side of the brain and this gives us “left brainers”, those logical people. The right brain, according to the myth, is the creative and emotional side giving us those creative and emotional “right brainers”. This is fundamentally wrong,but we do have two hemispheres and there is some location specific functioning. But first let’s understand the fascinating history to this myth.
Sperry & Split-Brain Patients
Much of the location in hemispheres dates back to the work and research of Sperry and his graduate student Gazzaniga on so-called split-brain patients in the 1960s and 1970s. This led to a Nobel prize for Sperry in 1981.
Split-brain patients had had the corpus callosum, the bridge between the hemispheres in the brain, cut through to relieve epilepsy. They hence had two unconnected brains in their skull. Outwardly these individuals behaved completely normally but on closer inspection and research some strange anomalies appeared:
- Words project to the left hemisphere could be remembered and verbalised, but not when to the right.
- The words projected to the right hemisphere could, however, be drawn by the left hand (controlled by the right hemisphere).
- When projecting words to right hemisphere study participants could pick up the right object but couldn’t verbalise what it was.
Sperry hence saw that the right had language recognition but no articulation and that the two hemispheres in split-brain patients did not acknowledge the existence of each other.
He did, however, presciently, warn that “experimentally observed polarity in right-left cognitive style is an idea in general with which it is very easy to run wild… it is important to remember that the two hemispheres in the normal intact brain tend regularly to function closely together as a unit”
The Myth grows
According to Psychology Today:
The New York Times Magazine in 1973 published an article, “We are left-brained or right-brained”, that began: “Two very different persons inhabit our heads, residing in the left and right hemispheres of our brains, the twin shells that cover the central brain stem. One of them is verbal, analytic, dominant. The other is artistic…” Two years later, Time magazine featured the left/right story. In 1976, Harvard Business Review published “Planning on the Left Side and Managing on the Right” and the following year, it was Psychology Today’s turn to trumpet the idea. The 1981 Nobel Prize in Physiology or Medicine that Sperry received for his split-brain research opened the floodgates.
The myth is not so much a myth as a dangerous oversimplification. The brain does have two hemispheres and there is localisation of some functions but even these always operate in tandem with other areas of the brain including alternate hemispheres. For example, language is normally based in the left hemisphere, but as a highly complex cognitive and behavioural process uses resources from areas in language such as Broca’s and Wernicke’s areas in the left hemispheres but also for tone and intonation in the right hemispheres. The left seems to be more specialised in words and grammar and the right on the flow and tonality of language. This would suggest different processing of language also for tone-based languages such as Chinese.
What the left and right hemisphere actually do:
Here are some functions which have been localised
- Sides of body: left part of brain controls right side of body, and right side of brain controls left side of body
- “Shield and Sword” – the dominant handed-side of the brain control approach and attack behaviours, “Sword”-based behaviours. The non-dominant handed side of the brain controls avoidant and defensive strategies – this is the “Shield”. These are also known as “Avoidance” behaviours in psychology. These are therefore opposite depending on one’s handedness.
- Language (vocabulary and grammar) are clearly domains of the left hemisphere.
- Emotion expression and recognition of these seems to be the domain of the right hemisphere
- Internal attention seems to be controlled by the left and external attention by the right
- Focused attention is left and broad attention (scanning) is the right
The best explanation and exploration of the hemispheres is that of Iain McGilchrist and his book “The Master and His Emissary. He eloquently and in scientific detail outlines why he sees the right hemisphere as the Master and the left as its Emissary and why, tragically, in modern society we seem to have become slaves to the left. Iain McGilchrist lists these functions for the right and left and this is the description we find most useful:
We can see here that the left is the domain of the specificand focused, much of this can be considered “cognitive ability”, but not exclusively. The right is the more generalist, embodied and human view of the world. McGilchrist cites the left as having “knowledge of the parts” and the right as having “wisdom of the whole”. His short animation video (11:24) can be viewed here.
This is also supported by other intriguing research. For example, following brain damage to the visual cortex we know that the right hemisphere can compensate for brain damage to the left hemisphere hence blindness in the right eye due to brain damage is unusual, but the left hemisphere cannot compensate for the right hemisphere so blindness in the left eye due to brain damage is vastly more common.
Mixed personalities seem to be high performers
Our research into personality using our Human Behavioural Framework (a fully comprehensive model of human personality) also shows that high performers in business, entrepreneurship, and teaching show high cognitive abilitiesand high intuitionwhich goes against the left/right principle but also against many other personality measurements which measure these on a sliding scale and not separately. So high-performing brains seem to be not just more cognitive but better at everything!
How will this help in teaching?
Left-right dichotomies and related brain science show that the following should be applied in the classroom to stimulate effective use of the brain and growth of important faculties:
- General to specific– not really news but sometimes forgotten, move from general broad theories to specifics of these.
- Working with paradox– “how long is a piece of string” concepts help reasoning and ability to deal with multiple variable situations in everyday life.
- Use divergent thinking exercises– “how many uses can you think of for a brick” – these stimulate varying contextual uses and break down limiting barriers to thought and conceptual thinking.
- Structured playcreates structure but enables contextual thinking
- Sitting with ambiguitywill help general development of cognitive abilities
What to avoid in teaching
Similarly, some faults in teaching, which are generally recognised in other literature (and will come as no surprise to many), are the following:
Note on movement: Moving left and right hands does not activate right and left hemispheres but activates the motor cortex. Movement is a good activator in general but not necessarily for brain connections! (so, do use movement but don’t assume, falsely, that it will activate right and left)
- Rote learning where possible – this removes context and is an unnatural form of brain processing (can be used in limited contexts)
- Too focused without context– missing context can lead to a loss in meaning
- Too focused for too long– the brain operates by alternating between focused and non-focused tasks
- Avoid giving answers – allowing the brain to work towards answers stimulates learning. We desire the answer, but this inhibits true learning. Obviously, we do not want to frustrate students so striking the right balance is the challenge (and can be a real challenge at times!).
Blog Learning Exercises*
To practice what we preach we give three exercises using the best of brain and learning techniques:
Learning Friction Exercise
Why does Jarret’s article here draw some negative comments – read comments and review his article.
Learning Ambiguity Exercise
Left and right are only connected with a bridge of fibre (Corpus Callosum) these fibres are, however, inhibitory that means they inhibit processing rather than excite processing. So, the hemispheres seem connected not to share information but to inhibit information. Why do you think the reasons for this could be?
Paradoxical thinking Exercise
How do we strike the right balance between generalist thinking and specific thinking or general rules and specific rules?
*Learning frictionis when we have to apply more effort or discomfort to learn something, it becomes more effective – so simple, fun learning is sometimes not as beneficial as more difficult or less pleasurable exercises!
*Learning ambiguitycreates a reason for the brain to resolve ambiguity – when the world is stable and unchanging the brain does not need to learn so creating ambiguity is beneficial to learning and also stimulates friction.
*Paradoxrelates to the above two but are unresolvable issues but still enable and stimulate learning through being able to deal with unresolvable situations.
Why the left brain right brain myth will probably never die
Roger Sperry’s Split Brain Experiments (1959–1968)
Divided Brain – Divided World, Iain McGilchrist
The Master and his Emissary, Iain McGilchrist
The split brain: A tale of two halves
Left Brain, Right Brain: Facts and Fantasies
Neuromyths in education: Prevalence and predictors of misconceptions among teachers
Dispelling the Myth: Training in Education or Neuroscience Decreases but Does Not Eliminate Beliefs in Neuromyths