I recently had the opportunity to sit down with other scientists—along with famed director Julie Taymor and legendary composer Philip Glass—to wrestle with the riddle of genius. I found one observation that Taymor made about cultural and environmental influences on cognitive traits very perceptive (see the video above). We have always understood that whether you are Muslim or Mormon largely depends on where you were born and raised, but neuroscience is showing us that this environmental influence on the mind goes beyond teaching—the physical structure of the brain is molded by the environment in which it is raised.
Our cognitive abilities (and our brains) are different from those of our ancestors whose survival depended on a different set of skills. The brains of people raised in different environments and in future generations will be different too, just as differences can be seen in the brain structure of people who excel at different skills (mathematics, music, mastery of foreign languages, and reading ability, for example). We can see this evolution of cognitive abilities in a changing environment taking place in our own culture right now. An article in the August 5, 2011 issue of Science by Sparrow et al. documents that as people have increased access to the Internet, mental recall of information itself declines and instead, memory of where the information can be found is enhanced. To cite another specific example, the mathematician and “Genius Award” recipient, Stephen Wolfram, never learned to do long division. With computers that calculate faster and more accurately, why waste brain tissue to develop this cognitive skill? One wonders whether this might have freed up cognitive resources for more abstract mathematics. (Neuroscientist Gary Small argues a similar point.)
The fact that the human brain develops after birth—through childhood and adolescence—according to the environment that is experience during rearing, makes perfect sense from an evolutionary perspective. Adding environmental control of brain development to the pre-programmed genetic controls will produce a brain providing the greatest likelihood that the individual will survive and reproduce in the particular environment that one is born into. This flexibility of brain development according to the environment in which one is raised is the primary reason for the success of humans as a species over time and over so many different environments on the globe.
This is why, if you want to become a genius, you are well-advised to start practicing early while your brain is still developing. Does this mean that parents should enroll their children in music lessons to make them a genius? Hardly. Doing that would guide development of their child’s brain in ways that will make them very good musicians, but the important message here is that whatever one does with their brain while it is developing (up to about the age of 20 years or so), will result in a mature brain that is very good at doing whatever it was that one did with it during those formative years.
We are learning more about how functional activity in the brain influences its own development. A new paper published in Science from my lab last week reports at a molecular level how the electrical insulation on nerve fibers, called myelin, is stimulated to form by the electrical impulses in the nerve fiber. Myelin is formed on nerve axons in late stages of fetal development, but myelination continues through childhood and adolescence, and it is not completed in some brain regions until the early twenties. Myelin insulation increases the speed of information transmission through nerve fibers at least 50 times, so whether or not a fiber becomes insulated will have a profound influence on how information is processed in neural circuits. This new research shows that one important factor determining whether an axon gets myelinated is whether it is functionally active. Which axons are functionally active depend in part on environmental experience activating particular neural circuits.
Perhaps more important than searching for the pathway to genius, we should also consider the converse consequences of this postnatal influence on brain development. If a child is raised in a socially impoverished, abusive environment, or bullied by peers, or denied intellectual experiences required for success in broader society, the brain that is produced will be one that will maximize success under those hostile conditions. Personality, social interaction, physical abilities, propensity toward violence, tendency toward addiction, attitudes toward family. and so on are profoundly influenced by the experience one has during childhood and adolescence when the brain is wiring itself up, and the results can be long lasting.
But this new information is also empowering. It tells us that through experience we can “wire” and “rewire” the brain. We are not necessarily captive by a fate determined by the chance of genetics. Brain imaging shows that people who become blind rewire the part of their brain that normally processes visual information to instead process sound. This enables blind people to comprehend speech sped up far faster than a sighted individual can comprehend.
Recognizing that every child’s brain develops on a somewhat different trajectory could be important for education. There are critical windows of opportunity for the environment to have its effect on different mental functions. This could mean that an educational approach that categorizes and sorts by ability to progress on a particular time-line could fail to develop each child’s potential fully.
For example, learning to read restructures the brain—we can see it with human brain imaging. Children with dyslexia have developmental differences in the brain pathways activated by the process of reading. Eventually most children with reading difficulties learn to cope, which means that in doing so they to some extent rewire their brain; but this can take years. Such children, while they are struggling to read, may not be able to read or spell as well as their peers can, but they might be able to fully appreciate the literary aspects of Shakespeare—character, plot, the insight into human nature it provides. Yet they could be deprived of such an experience to learn these things if their environment denies them the opportunity. Frequently such children are held back until their reading abilities develop rather than having their reading delays accommodated so as to develop their other intellectual abilities. Neglect through impoverished environments will alter the trajectory of brain development in ways that can persist into adulthood.
It is in part the unique experience everyone has through childhood that makes everyone’s brain different. It was an honor to have an opportunity to listen to such talented individuals on the panel that night, but it was especially delightful to see how each one’s talent was so unique.
Carreiras, M., et al., (2009) An anatomical signature for literacy. Nature, 461: 983-986.
Fields, R.D. (2011) Imaging learning: The search for a memory trace. The Neuroscientist, 17: 185-196.
Sparrow, B., Liu, J., and Wegner, D.M. (2011) Google effects on memory: Cognitive consequences of having information at our fingertips. Science, 333: 776-778.
Wake, H., Lee, P.R., and Fields, R.D. (2011) Control of local protein synthesis and initial events in myelination by action potentials. Science (Accelerated publication in Science Express, August 4, 2011) DOI 10.1126/science.1206998.
This article originally appeared at Scientific American on August 20, 2011.
More from this ongoing series: Beautiful Minds: The Enigma of Genius