"The great pleasure and feeling in my right brain is more than my left brain can find the words to tell you."
Nobel Laureate Roger Sperry
The rationalists vs the imaginative/visual types
So what happens when we don't use our brain to shuttle information back and forth between the two cerebral hemispheres in a balanced way? If the process is not balanced for an extended period of time, one of two things is likely to happen:
- A person whose information is made to flow primarily from the R-brain and/or from the sensors to the L-brain through the corpus callosum will remember and recall very quickly a plethora of facts, figures and other patterns, but may not be able to relate well all these patterns to the larger pattern of reality (which some psychologists categorise as L-brain people); and
- A person whose information flows from the L-brain and/or from the sensors to the R-brain through the corpus callosum can see a larger and more unified picture of reality after assembling known or observed patterns in many different and creative ways through the process of thinking, but may not be able to find enough words to explain the picture (which some psychologists categorise as R-brain people).
Can we describe people as predominantly L-brain or R-brain types?
Generally no. People do have the ability at different times and when we choose to switch the direction of flow of the information through the corpus callosum and hence have the ability to apply opposite functions of the brain. And although certain specific functions in one side of the brain or the other may appear to dominate in the processing of the information, during problem-solving (especially in the frontal cortex region) it seems both left and right cerebral hemispheres do get activated. So, technically speaking, we are not strictly "L-brain" or "R-brain". We are essentially both types. The terms have been created to describe our preferred approach to solving problems using a "cognitive style" as neuropsychologist Associate Professor Michael Sailing from the University of Melbourne at the Austin Health's Epilepsy Research Centre puts it. As Sailing said:
"When someone says they are right or left-brain it's really just a metaphor for a cognitive style. Without a doubt the popular left and right division of the brain is an over-simplification. For example, research is showing that musical, artistic and intuitive thinking can't be thought of as strictly lateralised, or exclusively of the right hemisphere". (Mitchell, Natasha. Left Brain, Right Brain: ABC Science. 24 June 2004.)
In other words, Sailing believes the functions are probably "lateralised" in the brain for a good reason but the process of creating and recognising and recording patterns during problem solving appears to utilise both hemispheres. As Sailing said:
"Every single cognitive function has right hemisphere and left hemisphere components. To avoid competition between the two halves of the brain there is a division of labour between the left and the right"
Another observation concerns left- and right-handedness of humans. Most people (estimated to be about 90 per cent) write and perform significant manipulations of an object with the right hand. This means the hand is controlled by the opposite side of the brain (i.e., the L-brain), and studies of the brain activity involving the processing of languages tends to lie in that region of the brain controlling the dominant hand. With this in mind, people who are right-handed can have L-brain functions such as language processing in the right-side of the brain (opposite for most people).
It seems the difference between L-brain and R-brain lies in the way information gets transferred through the corpus callosum for processing which determines how likely our behaviour will be seen by others as more L- brain (i.e., the breaking down of information into recognisable and observable patterns using our memory and have direct and immediate influence on our primitive functions, such as the familiar flight and fight response) or R-brain (i.e., the assembling of patterns to create new patterns for creative activities and thinking the bigger picture).
This may explain why a 2-year study by University of Utah researchers on brain scans of 1,011 people aged between 7 and 29 years found no obvious increase in brain activity on one side of the brain or the other for people who might be described by others as more L-brain or R-brain in their behaviours (and hence personality). It is not the side of the brain with the most activity that determines whether we are more L-brain or R-brain, but rather the flow and direction of the information through the corpus callosum is the more critical factor in this controversial discussion.
In fact, the University of Utah study is the basis for articles written online to debunk the existence of L- and R-brain behaviours and thinking because many writers and some scientists believe human behaviour is too complex to be stripped down to just L- or R-brain. For example, the editor of NeuroScientist News wrote in his article "Myth-conceptions: How myths about the brain are hampering teaching" on 16 October 2014:
"Over 70 per cent of teachers in all countries wrongly believe a student is either left-brained or right-brained, peaking at 91 per cent in the UK.
And almost all teachers (over 90 per cent in each country) feel that teaching to a student's preferred learning style - auditory, kinaesthetic or visual - is helpful, despite no convincing evidence to support this approach."
This statement is based on research conducted by Paul A. Howard-Jones of the University of Bristol, published on 15 October 2014 in Nature Reviews Neuroscience. The article is titled "Neuroscience and education: myths and messages".
It should be remembered that this quote only holds true for young people, especially those going to school and, therefore, able to learn different ways of problem-solving to help force the information to flow through the corpus callosum in both directions. As we grow older, this is not the case. Somehow the brain decides we should become more accustomed to a preferred way of solving problems (or forced in a certain way by the nature of our employment and the chase to reach the top of the career ladder) that effectively sees the information flow moving more in one direction or the other that helps psychologists to see opposite differences in behaviour over time called L- and R-brain behaviours.
So yes, L-brain and R-brain types are not a myth and certainly not debunked by scientists ¡ it is just harder to detect the difference in young people.
More on the University of Utah study
As scientists know, heightened brain activity occurs when there is a passage of electrical impulses through neurons and their connections. Since neurons are small and there are so many in the brain which can potentially fire electrical impulses, the greatest interest for scientists are in larger regions of the brain where multiple neurons work together and in close proximity to each other to help achieve some particular type of function. Whatever the function these nuerons perform, it becomes easier to see the brain activity as a bright spot in brain scans due to the number of these neurons, the increased number of connections they make with each other, and whether these neurons are required to perform a certain function.
For the researchers involved in the study, the question was whether in the rest state the brain scans of a large sample of individuals described as more L-brain or R-brain showed any increase in brain activity for one side of the brain or the other.
The results are in and can be found in the August 2013 journal of PLOS ONE. The article is titled, "An Evaluation of the Left-Brain vs. Right Brain Hypothesis with Resting State Functional Connectivity Magnetic Resonance Imaging".
The results of the study indicate no obvious signs of greater brain activity in one side of the brain or the other. In other words, the brain had not used only one side of the brain or the other at the time the people who might be described as more L- or R-brain (i.e., rational or creative thinkers) in their daily activities were scanned for brain activity. As Jared Nielsen, a graduate in neuroscience and one of the researchers involved in the study, said:
"Everyone should understand the personality types associated with the terminology 'left-brained' and 'right-brained' and how they relate to him or her personally; however, we just don't see patterns where the whole left-brain network is more connected or the whole right-brain network is more connected in some people. It may be that personality types have nothing to do with one hemisphere being more active, stronger, or more connected." (Quote from https://healthcare.utah.edu/publicaffairs/news/current/08-14-13_brain_personality_traits.html as of August 2013)
Lead author of the study, Dr Jeff Anderson, M.D., Ph.D., supports this finding when he said:
"It's absolutely true that some brain functions occur in one or the other side of the brain. 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." (Quote from https://healthcare.utah.edu/publicaffairs/news/current/08-14-13_brain_personality_traits.html as of August 2013)
It should be noted that the subjects were made to rest to allow the researchers the opportunity to perform the brain scans. Whether this makes a difference, one must assume the results would be the same in the case where the participants (especially for adults) were asked to perform the same functions described as L- or R-brain in their daily activities.
Does this mean the study has proven no L-brain or R-brain behaviours can take place because the brain scans for electrical activity look the same in both hemispheres? No. People are aware of differences in general behaviour and personality that are opposite in nature and those who behave in these opposite ways are not always aware of the differences. Something else is clearly going on in the brain to create these differences. The question is where in the brain these differences are likely to take place?
The answer may surprise some readers. It seems the key may lie in the corpus callosum. In particular, the general flow of this information through the corpus callosum.
The direction of flow of information through the corpus callosum
Therefore, it seems the question is whether people have a natural preference for problem-solving in a certain "cognitive style", or whether they can choose at will the "cognitive style" for problem-solving? And does this choice of "cognitive style" affect the direction of flow of the information through the corpus callosum?
Indeed, and more importantly for this research, does this direction of flow of the information through the corpus callosum from one side of the brain to the other affect human behaviour (and with it our personality)? From our research, it apparently does. People have observed general behaviours that are common and described as opposite in nature and can be categorised broadly speaking as L-brain and R-brain behaviours. This controversial theory will be discussed further.
Are the functions of the brain lateralised?
Of course, you might be wondering, are the functions in the brain lateralised in any way? In other words, are there functions that can be found predominantly on the left- or right-side of the brain? The answer is surprisingly a big "Yes".
Taking one step back from discussing this controversial idea of general L-brain and R-brain human behaviour, let us look at the scientific evidence supporting a biological separation of the brain functions being located in different cerebral hemispheres. To the scientists, this is called lateralisation of the brain.
The work of Professor Lesley Rogers
Professor Lesley Rogers of the Centre for Neuroscience and Animal Behaviour at the University of New England is presently the world expert in unlocking the behaviours generated by the L- and R-brains in animals.
In a series of experiments performed in 2003-04 on young chickens (and later monkeys), Lesley found evidence of a lateralisation of the brain that is, the cerebral hemisphere have different and opposing functions.
For example, when visual stimuli reaching the left eye of a day old chicken is blocked using a piece of cloth, the chicken initially applied a trial-and-error approach to finding the food. Once found, feeding on a pellet of food would provide all the reward needed to help the animal quickly memorise, recognise and later recall at a high rate of speed (i.e. to find food again) using the L-side of the brain (since the right eye is processed by the L-side of the brain). Because the chicken saw the benefit of learning and implementing a solution when finding food, the animal did not hesitate to perform the exact same action (virtually without thinking). There is no attempt to deviate from this action.
On the other hand, should the right eye be covered with the cloth, the R-brain processing the visual information from the left eye caused the animal to initially react to the environment as unfamiliar (perhaps even predatorial in nature) then a delay factor was needed to think of an "appropriate" action before it is performed. Even if the situation is repeated and positive rewards are provided for an "appropriate" action, the animal would still instinctively react and later delay the performance as it searches for an "appropriate" action.
In other words, there is a reaction time, or response latency, difference when either the functions of the L-brain or R-brain are applied first to a given situation or problem.
Professor Rogers repeated the experiment with other young chickens and noted the exact same result. So he later tried the experiment with monkeys (by observing the animals behaviour on the basis of whether they were naturally L-handed or R-brain, or R-handed or L-brain since the side of the brain controls the opposite hand (1)). In other words, behaviours observed in at least these animals are not only opposite in nature but appear to follow the functions of the R- and L-brain.
Evidence for a "lateralised brain" theory for humans
Does this translate into humans? Well, yes to a certain extent, especially for young subjects. For older people, however, this is less obvious. In research conducted by the Center for Cognitive Neuroscience at Duke University in 2002, it suggests as humans grow older, prefrontal activity for processing information as required for effective cognitive performance "tends to be less lateralized". Either the individual, as he or she gets older, has acquired enough patterns and practiced sufficiently different things to allow a balancing of the brain's L- and R-brain functions, or some other process is taking place in the brain.
Nevertheless, certain things appear to be in common between humans and other animals. For example, scientists have noted how the human brain does attempt to lateralise certain functions relating to language comprehension to one side of the brain, and functions relating to assembling known patterns in memory into an arrangement of new and creative visual images, sounds and motor control are found on the opposite side.
According to Dr James "Jim" Donnelly while working at the Department of Psychology at the University of New England in 2004, he has studied a small sample of university students subjected to a problem-solving test and compared this to the rest state to help determine which side of the brain is active (i.e. preferred) by the participants and to see how the participants felt in performing the problem-solving test, although the experiment did also reveal another observation, the "cognitive style" chosen by participants for problem-solving. As Donnelly explains the purpose of the experiment:
"As a clinical neuro-psychologist I work with people sometimes, who have disorders in personality or emotional functioning. And so it's, it's fascinating to me to understand what gives rise to those individual differences." (ABC Catalyst: Left Brain, Right Brain. 24 June 2004)
The problem-solving test involved nothing more than working out a secret five digit code randomised at the start of each test for every participant to avoid revealing a pattern in the code generation. During the test, the participants were given feedback by way of a loud beep when an incorrect choice of a suggested code is made.
In summary of the results according to the Catalyst program, Donnelly discovered the participants with left frontal asymmetry were "gregarious, outgoing and risk takers". And people with right frontal asymmetry were "more emotionally negative, anxious and cautious".
But on observing the actual experiment as televised on the Australian premier science program on ABC television known as Catalyst, SUNRISE also noticed evidence of a difference in the way the participants approached the task of problem-solving. During the test, a group of people described as L-brain frontal types were applying the trial-and-error approach to finding the solution in a quick manner. The negative reinforcement of the sound was not slowing them down. On the other hand, another group of people described as R-brain frontal types behaved in the opposite way. They were focussed on the negative reinforcement of the sound for an incorrect choice and therefore tended to be more cautious and would prefer to take more time to solve the problem by thinking about it. In fact, even Donnelly confirms he has seen a delay in the time it takes for "right frontal brain" participants to solve the problem when he said:
"He's [a participant] waiting for the feedback here, you see the increased tension. Wow, wow."
In fact, what's the difference between "waiting" and "thinking"? None. It is more likely the R-brain frotal types were thinking on a right course of action.
This simply reaffirms two different "cognitive styles" to problem-solving. A crucial observation for determining the "lateralisation" of the brain especially if the participants have a general preference style and is maintained over a period of time.
The existence of these "cognitive styles" would explain Donnelly's observation of the emotional response of the participants. In other words, "right frontal brain" people probably felt they were under pressure to find a solution and/or were feeling frustrated in not finding a pattern in how the code was generated and the negative reinforcement of the sound was exacerbating the negative feelings (2). But tell the participants the code is randomised and remove the negative reinforcement but just show how close they are to the answer would probably result in an opposite emotional response. But can we be certain about this? Unfortunately the experiment did not gather data on the general preference of the participants in the choice of a "cognitive style" for problem-solving. The assumption in the experiment, as Donnelly has confirmed to us, is that participants probably knew of the two different approaches to problem-solving and chose the one that suited them at time the test was performed.
In which case, from our point-of-view, it will be necessary to conduct another study to measure the time response latency in pressing the buttons by the participants when suggesting a code during the test to see if people consistently delayed the selection or were quickly trying the trial-and-error approach. Perhaps multiple tests and a questionnaire will reveal this information?
So, is there a lateralisation of the human brain? Probably there is. It is just humans are much harder to tell.
Can humans be identified as L-brain or R-brain from the side of our body we use the most?
When R-brain (the more creative and visual) and L-brain (the more rational and memory specific) types in human subjects were identified, researchers have checked the preferred side of the hand the individuals used most of the time. As stated in http://encyclopedia2.thefreedictionary.com/hemispheric+asymmetry, researchers noted the following:
"Since the left and right cerebral hemispheres control the right and left sides of the body, respectively, right-handed people are typically left-dominant in terms of hemispheric control of various motor functions and also with respect to seeing (right-eyed) and language comprehension....Later researchers discovered that functions involving logical or sequential analysis generally reside in the left hemisphere, while the right hemisphere seems to control processing of spatio-visual information and musical relations."
But to complicate things a bit for humans, the R-brain types do have an added feature:
"More left-handers than right-handers display a reversal of hemispheric specialization or a more even distribution of functions between the two hemispheres."
And, of course, there is the complicating issue of the age of a person when determining the extent of lateralisation in the brain as we have seen earlier by the Center for Cognitive Neuroscience at Duke University.
Because of these subtle and complicating differences, Dr Donnelly preferred to use EEG to measure electrical brain wave activity to determine which side of the brain people tend to use (especially the frontal lobes where problem-solving takes place). As stated in the Catalyst program:
"Unfortunately, in humans, hands don't tell you which side of the brain is dominant for personality but brainwaves can. So what we're going to do here is place some sensors here over the frontal part of the brain." (ABC Catalyst: Left Brain, Right Brain. 24 June 2004)
So what did the EEG results reveal?
The result Donnelly found according to an email sent to SUNRISE is that there was an equal distribution of activity across both sides of the frontal cortex during problem-solving. But one side of the frontal cortex or other may be activated in the brain's rest state. As the transcript of the Catalyst program revealing Donnelly's experiment and results shows, the science presenter stated:
"The EEG reveals that Bart, our first student, has more electrical activity in the left frontal lobes of the brain. While Marshall is slightly more right brained [presumed to be in the rest state].
Like the marmosets, to find out whether left and right brained people had different personalities, Jim needed to put them under pressure. How will they react to a problem solving test?" (ABC Catalyst: Left Brain, Right Brain. 24 June 2004)
Hence the reason for the problem-solving test. It is during this test where Donnelly claims both sides of the frontal cortex were activated during problem-solving. As Donnelly said in an email of 11 July 2011:
"...there is no left [or right] frontal person...there is a continuum of frontal brain asymmetry that shows up in various frequency bands of the the EEG. The absolute power in any frontal region does not relate to anything. Both regions are activated, in fact most of the brain is activated on most tasks...."
In conclusion, if we use the labels of L-brain and R-brain types to describe certain behaviours to show the preferred "cognitive style" for problem solving, the side of the frontal cortex people were most in touch with in the "rest state" seemed to determine the personality of the individual in terms of his/her emotional response and feelings towards solving a problem. As Donnelly stated:
"Where the left frontal person might be a little more extroverted, more willing to take social risks, because they're driven by the opportunity for positive things. Where the person who's right frontally activated might be more driven by avoiding more negative things." (ABC Catalyst: Left Brain, Right Brain. 24 June 2004)
Whether this statement had been accurately quoted by Catalyst according to Donnelly when he said to SUNRISE that "It [Catalyst] paraphrased from a lot of things I said over a daylong process", neuroscientist Richard Davidson, co-editor of The Asymmetrical Brain, who scans the brains of people to explore the neurological basis of emotions, gave support for Donnelly's previous statement when he said:
"Our evidence suggests that individuals who exhibit greater activation in certain regions of the left prefrontal cortex have a more positive dispositional mood, that is, they are happier people" (Mitchell, Natasha. Left Brain, Right Brain: ABC Science. 24 June 2004.)
Based on this supporting quote, we must consider the Catalyst program discussing the now-published experiments and results of Donnelly to be sufficiently accurate.
However, when it comes to the individual's preference in "cognitive style" for regularly solving a problem and what's happening in the corpus callosum and how the maintaining of this problem-solving style over a long time can affect human behaviour (and ultimately our personality) has yet to be analysed. The only clue we have to determining whether a person is likely to be more L-brain or R-brain dominant in his behaviour over a long time is the time factor of how long it takes to choose a course of action to solve a problem and how regularly this is applied. This is something that needs closer attention by the scientists.
As of 2008, other researchers are investigating this response time latency issue to determine what is happening in the brain and how human behaviour is formed. They include Dr Don Bradshaw, a professor in neuropsychology from the University of Western Australia, who is thought to be the first to suggest this response time latency possibility in the L- and R-brain as early as 1969 but didn't have the computers to accurately measure the time difference (now thought to be in the milliseconds).
Should we classify people as L-brain or R-brain types?
There are opposite differences in general human behaviour whether we like it or not. It is just a matter of how we wish to label those differences to help identify the observations in support of the opposing patterns we see in people. For now it seems the best way to describe the differences is by using the terms l-brain and r-brain.
Of course, people don't like to be labelled as more L-brain or R-brain by others. Labelling can sometimes make us feel less important than other people. It can sometimes make people think they cannot change. All this is untrue. The fact is, our brain is a powerful tool. It has the incredible flexibility to change the way we behave over the long term. So long as we reinforce those changes positively and regularly, the behaviours will change and fewer people will be able to label you as one extreme or the other. But even if we don't change, there is nothing wrong with people who are more L-brain or R-brain in their behaviours. The differences doesn't make people less of a human being. They just add greater interest to the way we live, to force us to switch between opposite extremes so we can become more aware of where the balance should lie. Without these differences and we have no hope of knowing if our behaviours are the best they could be when interacting with other people.
We should not be upset if we are labelled at certain times as bring more L-brain or R-brain in our behaviours. It is not meant to be a bad thing.
Which is the better approach?
Okay. So we have two groups of people who approach a problem in two different ways, or "cognitive styles" of problem-solving that we would describe as more L-brain or R-brain. Whether lateralisation of the brain functions play a role in these differences or within the corpus callosum (or perhaps a combination of both), is there a correct approach to problem-solving?
Neither approach is right or wrong. Both have their advantages and disadvantages. But if thinking and the actions we take in life are to be truly effective, creative, the most "appropriate" and relatively quick in the attainment of a quality and potentially unique solution (i.e. to recognise/remember the best pattern, to create the best pattern, and to apply the best pattern based on the information provided), there is a need for balance. Otherwise, our potential to think, problem-solve, and act on things quickly and effectively and thus achieve great things in life is substantially reduced.
And more significantly, our behaviours soon become affected by prolonged imbalances in our thinking and how we do things, resulting in the appearance of what psychologists call L-brain and R-brain people in society.
In the next two sections, we shall present a simplified psychology of human behaviour that transcends cultural frameworks, religious views and other social boundaries. We will describe the most common L-brain and R-brain behaviours displayed by all human beings (and even living things in the animal kingdom) as a result of this unbalanced shuttling of information between the two cerebral hemispheres. (3)
It is a controversial theory. Not everyone will feel comfortable by what we will attempt to do. At the same time SUNRISE acknowledges that it is not always possible to categorise all people at all times as being L-brain or R-brain. At certain times we apply certain functions that led us to being more L-brain or R-brain in our behaviours and later we may reverse the functions. This switching effect provide a high level of complexity in human behaviour. But the crux of our research work is that there are observable differences in general (rather than specific) behaviours described as opposite in nature. We prefer to categorise these general behaviours broadly as L-brain and R-brain behaviours for lack of better terms.
So, let us introduce the controversial theory.