Sunday, January 18, 2015

The Myth of the Right/Left-Brained Learner

Recently, my school's staff newsletter promoted the book Brain–Based Strategies to Reach Every Learner by J. Diane Connell. Unfortunately, the book is a prime example of pseudoscience in the education community. With chapters on “Are You Left-, Right-, or Middle-Brained?,” “What Are Multiple Intelligences?,” and “Learning Styles,” the book nicely illustrates many of the myths that pervade education.

Teachers today are routinely taught to accept these “brain-based” theories as fact and incorporate them into their teaching, even though little evidence exists for them. In fact, some have been entirely debunked, but continue to be accepted as gospel in education circles. 

The book will provide fodder for a number of posts, but today, let’s start with the left-brained/right-brained myth. Time to do some myth bustin’...

The Myth: It’s hard to not be familiar with this one, given the pervasiveness of the left-brained/right-brained myth, but, in a nutshell, there is a popular belief that the two hemispheres of our brain perform very different functions- the left side controls logic and reasoning (educationally, the math and science side), while the right side is creative (educationally, the writing and art side).

Just as some people are right- or left-handed, the myth states that most people tend to have one side of their brains that is more dominant than the other. Proponents of this idea believe that logical and analytical people are left-brain dominant, while creative and artistic types are “right-brained.” Of course, just as there are ambidextrous people, most versions of the mythology hold that some people are middle-brained, or balanced.

The Grain of Truth: Like most education myths, there is a grain of truth to be found within the myth. Neurologist Steven Novella summarizes the roots of this myth on his fantastic Science-Based Medicine blog:

It is certainly true that the brain is divided into two hemispheres, right and left. These hemispheres also carry out some different tasks. Specific cognitive abilities localize in one of three basic patterns. They can be bilateral or diffuse, so they do not localize to one hemisphere. Much of what our frontal lobes do, such as attention, are bilaterally redundant in this fashion.

Other abilities localize to both hemispheres for the opposite side. For example, each hemisphere processes vision for the opposite side of the universe.

Still other abilities are localized and lateralize to one hemisphere. For left-hemisphere-dominant people (which is most people) language and math localize to the left hemisphere, while music and visual-spatial processing localize to the right hemisphere. It is this fact which seems to have led to the right brain-left brain idea.

So, there is some kernel of truth underlying the myth. More importantly, up until the 1970’s, there was experimental evidence to support this idea. If you want to delve into it, OECD’s Centre for Educational Research and Innovation (CERI) has a great summary of the scientific history behind the myth

Unfortunately, proponents of the myth seem to be stuck in the 1970’s and have not only ignored more recent research on the subject, they have created real problems by trying to overgeneralize brain localization so that it somehow creates specific personalities or learning styles in children (or adults). Let’s take a look at the truth.

The Truth: While there are cognitive functions that do localize within one hemisphere of the brain, most high level functions depend on both sides of the brain. For example, while language functions such as vocabulary and literal comprehension localize in the left side of the brain for most people, “higher level” comprehension depends on the right side (where most people localize functions that process emphasis, intonation, sarcasm, and the like. Without both sides, students would not be able to be strong inferential readers.   

Interestingly, even the gross generalization of language localization is not accurate. Basic language production and comprehension centers are sometimes located in alternate hemispheres of the brain in different people (particularly in left-handed individuals, but this occurs even between right-handed people as well).

Most importantly, however, that localization that doe occur in no way implies that our overall learning style similarly localizes in one hemisphere. As research has continued past the 1970’s and we have been able to gain a significantly greater understanding of brain function, we had found more and more evidence that the hemispheres are highly interconnected. Both hemispheres work together to manage many of of our cognitive functions.

In a 2013 study, for example, neuroscientists analyzed brain scans of more than 1,000 people while they were resting or reading, and broke the brain down into 7,266 regions. While they did find lateralization of brain functions, “left- and right-lateralized hubs formed two separable networks of mutually lateralized regions.” The researchers conclude, “lateralization of brain connections appears to be a local rather than global property of brain networks, and our data are not consistent with a whole-brain phenotype of greater ‘left-brained’ or greater ‘right-brained’ network strength across individuals.”

If none of that convinces you, how about the fact that it is difficult to find ANY neuroscientists or psychological researchers that support the right-brained/left-brained myth? Neurologist Steven Novella’s search for researchers still trying to support this myth, came up with exactly one. Unfortunately, a simple Google search for “teaching right-brained students” (or any other variation you choose to come up with) shows how riddled the education community is with this myth.

Simply put, there simply is no scientific support for the idea that teachers should be evaluating kids for brain “sidedness” or trying to teach in any way that incorporates sidedness.  Or, as others have summarized it:

“Brain-imaging studies show no evidence of the right hemisphere as a locus of creativity. And the brain recruits both left and right sides for both reading and math.” -Scientific American

“It's the foundation of myriad personality assessment tests, self-motivation books and team-building exercises – and it's all bunk.” - Christopher Wanjek, in the Bad Medicine column of LiveScience

Scientists nowadays think that while there are some functional asymmetries, the two brain hemispheres do not work in isolation, but rather together in every cognitive task. In light of this notion, using the conception of hemisphericity to guide and direct educational practice is highly questionable.” - CERI

Over 20 years ago, neuroimaging demonstrated that both sides of the brain are in constant communication, transmitting neural signals from one hemisphere to the other. Although parts of the brain are particularly active during certain memory or learning activities, all brain activities requiring cognition activate neural networks on both sides of the brain. Yet the myth persists.” - Neurologist and classroom teacher Judy Willis, MD

What’s the Harm? Even if brain sidedness is a myth, what harm does it do for a teacher to use it in his or her practice? After all, does it really hurt to teach students using a variety of approaches that get at the same learning goals from a variety of different strategies? Absolutely not! But, when we misunderstand why we do these things as educators, we open ourselves up to doing them for the wrong reasons and in the wrong situations.

Judy Willis looks at the harm from a couple important angles:

“Consider the financial and socioeconomic costs of commercial products falsely claiming neuroscience proof that all learners need what they offer. The expression ‘edu-cash-in’ is a reasonable description of people trying to capitalize on unsupported claims about the research behind the design and promised outcome of their books, cure-all learning theories, curriculum packages, and edtech products. Further, the falsehoods that neuromyths perpetuate also make educators skeptical about educational practices that actually have a strong evidence base, adding another layer to the problem."

However, I think the more important harm is in the minds of our students. One of the common prescriptions put forward by proponents of using the myth in classroom instruction is to have students take tests to help them identify the sidedness of their own brain. 

Imagine being a second grader and taking a “test” that tells you your brain is good at art, but not at math. Put yourself in the shoes of a small child who is going to grow up thinking that their brain is physically structured to struggle with math, that there is something physically wrong with him that is outside of his control.

Imagine instead, a teacher that understands the complexity and plasticity of the brain. Imagine that same child has a teacher that knows every normally functioning brain is fully capable of becoming a “math brain.” And a “reading brain.” Oh, and “a creative brain.”

Think of the very different futures that child faces just from one exposure to the myth.  Ask yourself again, what’s the harm?

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