The split brain research of several decades ago sparked many educators’ interest in our brain’s organization. The hemispheric separation of selected cognitive functions made sense to teachers who had long observed personality and ability differences in developing brains. Although the right-brain/left-brain rhetoric and learning styles inventories that emerged often went far beyond what neuroscientists had discovered, they continue to affect educational beliefs and practice.
Subsequent spectacular advances in imaging technology allowed scientists to closely examine specific hemispheric subsections in normal brains, and their discoveries led to the prevailing modular theory of brain organization. Simply stated, modularity means that our brain is composed of a large number of subsystems that process distinct functions (such as tone recognition), and these subsystems often combine to process related more complex tasks (such as word recognition and language comprehension and production).
Thus, at the hemispheric level, the left hemisphere (in most people) was believed to be specialized to process language, since people with left hemisphere damage suffer specific language deficits. But if processing language is the defining purpose of the primate left hemisphere, what purpose does it serve in non-human primates, species that don’t have a grammatical language?
In his marvelous new book, The Executive Brain: Frontal Lobes and the Civilized Mind, the renowned scientist Dr. Elkhonon Goldberg proposes a different perspective on modularity and brain organization. He argues that the hemispheric location of a cognitive function, such as language, is merely a special consequence of a more fundamental principle of primate brain organization.
Two central tasks confront an animal: stay alive, and get into the gene pool. To do this, it must have brain systems that can effectively recognize and respond to dangers and opportunities related to food, shelter, and mating.
Simple animal brains unconsciously coordinate recognition information in the thalamus and innate response behaviors in the basal ganglia. More complex animal brains supplement these basic structures with typically conscious processing systems located in the overlying sheet of cortex (which accounts for 85% of the mass of a human brain): Recognition: Sensory input and perceptual integration are processed in the occipital, temporal, and parietal lobes. Response: Decision-making and behavioral responses are processed in the frontal lobes.
Imagine a line across your skull from ear to ear. The sensory lobes are basically located in the back (above the thalamus), and the frontal lobes are in the front (above the basal ganglia). So the cortical and subcortical back-to-front organizing principle is recognition (back) and response (front) — but all these processing structures are also divided into connected right and left units.
Goldberg suggests that the fundamental organizing principle for the right and left units emerges out of an important question a brain must ask whenever danger or opportunity looms: Have I confronted this challenge before?
He provides considerable research evidence to argue that the right hemisphere (in most humans) is organized principally to process novel challenges, and the left hemisphere familiar routines. For example we process strange faces principally in our right hemisphere, and familiar faces in the left. Musically naive people process music principally in their right hemisphere, trained musicians in the left.
Goldberg argues that although both hemispheres are active in processing most cognitive functions, the relative level of involvement shifts from the right to the left hemisphere over time and with increased competence. The right hemisphere is thus organized to rapidly and creatively respond to a novel challenge, but the more linear organization of the left hemisphere eventually translates the successful initial responses into an efficient established routine that is activated whenever the challenge reoccurs.
It makes sense. Grammatical language is an efficient established procedure to enhance communication within a socially complex species, so it’s not surprising that considerable left hemisphere space is devoted to it. An infant uses whatever non-verbal communication skills it can creatively muster to get the help it needs, but happily spends much of its childhood mastering the much more efficient existing cultural language template we pass from generation to generation.
Similarly, children don’t have to create personal routines for many other cognitive functions— from tying shoes to flying kites. We teach them how to do it. There’s no inherent logic to the order of the letters of the alphabet but it makes sense (for data classification purposes) for everyone to use the same sequence, so preschool children learn the alphabet song long before they need to use a dictionary.
We invest heavily in parenting and schooling that inserts a wide variety of “cognitive prefabricates” (as Goldberg calls them) into our children’s left hemispheres. But what’s the point of mastering an established cognitive routine if the child hasn’t yet confronted an appropriate precursor of the adult challenge, and so doesn’t know when to activate the routine?
A child enjoys learning the alphabet song and all the attention its successful mastery brings. That the sequence has social utility is a serendipity discovered later. But what about learning how to divide 4723 by 69 when it’s difficult for a developing right hemisphere to even imagine the problem in real life? What about memorizing factual information of historical events that have no immediate or potential personal meaning? The continuing parental/school challenge is to create an appropriate mix of exploratory and didactic instruction.
It’s obviously important to master socially important and efficient routines, but left hemisphere routines are best developed through right hemisphere explorations focused initially on understanding the nature of the challenge. Schools too often teach students the answers to questions that the students didn’t ask.
Our extended sheltered childhood permits children to playfully explore the wide variety of survival problems and solutions that independent life will later present. But it’s only in school that such learning is called work, and is unremittingly formally assessed. In a misguided zeal for institutional efficiency, we often bypass right hemisphere explorations and immediately force the mastery of established routines that students haven’t had an opportunity to personally explore and develop. And we’ve now reduced arts and humanities programs that pose important problems well suited to extended playful exploration.
Small children are thrilled by familiarity turned into novelty, by puzzles they can easily solve. A father hiding his face behind his hands asks “Where’s Daddy?” and the infant squeals in delighted awareness. Presents hidden in wrapped boxes elicit excited guesses. New video games contain elements of mastered games. A child who wants to master a skill isn’t bored by extended practice.
Challenge stimulates children if it can creatively connect the novel with the familiar to solve a problem that is intriguing and that takes children into a more complex real life problem. The magnificent back-to-front right-to-left organization of our brain can enhance this maturation process, if we’ll but let it.
Goldberg’s book extends its focus into the key role that the frontal lobes play in cognition and problem solving, and so we’ll explore that issue in the next column. In the meantime, get the book and read it!