The principal reason that animals have a brain and plants don’t is because we can move of our own volition. Plants can’t, and so they don’t even need to know where they are. What’s the point of knowing that other plants are better situated if you can’t join them-or that a logger is approaching if you can’t flee?
But if an organism has legs, wings, or fins, it needs a sensory system to let it know about here and there, a decision system to determine if it’s better to be here or there, a motor system to go over there if that’s the better alternative, and a memory system that will get it back to here. That pretty much explains a brain. The human brain enhances its movement repertoire by being able to walk, run, and sprint, to kick and jump, and to grasp and throw. Perhaps more important, we seek to move with style and grace (the arts) and at a virtuoso level (the Olympics).
Social species also develop communicative movement systems to establish and maintain relationships and enhance survival. Many mammals use an intimate tactile form called grooming or caressing and visual/auditory signal systems that can communicate information at a distance. Human language and music are the most advanced of these systems.
Movement is so important to humans that most of our cultural narratives focus on it-from the Biblical Exodus to Homer’s Odyssey to Moby Dick to Lewis and Clark to Harry Potter-and to everything in between. Our folk heroes move purposefully or aimlessly, but they’re on the move. We dance the Hokey Pokey, and ask a lover to fly us to the moon.
Early Humans, Later Problems
Until perhaps 100 years ago, most humans spent their days expending physical energy- gathering food and securing their safety. Our brain thus evolved to regulate a relatively short life focused on the challenges of physical survival and reproduction. All four of my grandparents had died by the time I was born.
We used animals, and then developed wheels, wings, and engines for transport. Wire and wireless communication reduced our need to physically travel in order to interact with others. The result is that we have an ancient body/brain that’s biologically tuned to plan, regulate, and predict physical movement, but we’ve now inserted it into a typically sedentary culture.
Our ancestors died from infections and malignancies, but they lived a physically active life tuned to environmental rhythms. Medical science has reduced infections and malignancies, and has thus increased our life span-but we’re now confronting new kinds of health problems that emerge out of a longer life and the increasing disconnect between our sedentary culture and a body/brain that evolved to be on the go. It isn’t that we’ve become uninterested in movement, but rather that we seem to prefer watching the aesthetic and virtuoso movements of others instead of doing it ourselves.
John Ratey is a Clinical Psychiatrist at Harvard Medical School who has written several excellent non-technical books on biological issues that confront contemporary society. His latest (with Eric Hagerman) is Spark: The Revolutionary New Science of Exercise and the Brain (2008). The book’s basic message that exercise is good for us will come as no surprise to anyone. What the book does so well is to go one step further-to explain to general readers why and where exercise is important beyond its ability to enhance muscular effectiveness. That scientific information is now emerging, and it’s the core of an excellent book.
The authors use a narrative format to explain how we got into our current biological/cultural disconnect, and how we can run ourselves out of it. They describe the current kinds of research that provide understanding and direction, but imply that readers should just read through technical material if necessary, and focus on what the research means in their life. I found myself as fascinated by the narrative as I am when I’m reading a good novel (and Spark is certainly not fiction). Readers who want to check out the already extensive and growing list of supporting research should log on to John Ratey’s website, www.johnratey.com. When you get there, click on “Resources,” and then on “Spark – Bibliography.”
The basic story is that medical science has tended to chemically treat the disorders that are related to the disconnect between our biology and culture. The authors don’t discount the success of this approach, but argue rather that an exercise regimen should also be a part of the treatment (and possibly in some cases a viable substitute)-and that the supporting scientific evidence for this now exists. The reality is that most us aren’t going out today to plow a field by hand, so we’ve turned what in earlier eras had been physical work into a form of contemporary optional physical play-jogging, swimming, working out on gym apparatus, running in charity races, playing racquet ball, and the like.
Since our brain’s principal task is to plan, regulate, and predict movement, a regimen of intense physical activity will enhance related cognitive functions (such as attention, learning, and problem solving). The book includes chapters on current major concerns-stress, anxiety, depression, attention deficits, addiction, hormonal changes, and aging-and in each case provides a functional explanation of the relevant research, and helpful advice on how a deliberate exercise program can alleviate problems and enhance a sense of well-being.
The book has a wonderful beginning chapter focused on the now nationally recognized exercise program developed by a Naperville Illinois secondary school PE teacher. The program is credited for increasing test scores and improving the behavior of students and the culture of the school. Only 3 percent of the 19,000 students are overweight (by BMI standards), as compared to 30 percent nationwide.
We’re living in an era in which the value of PE has been discounted in a mindless attempt to improve test scores by getting students to sit still (like plants). It’s thus an absolute joy to read that the reverse is true. Movement is our brain’s central property, and so it should also be central to the curriculum. When students figuratively plow a field every day in PE, they end up feeling and doing better during the rest of the school day.
And if it’s true for adolescents, it’s even truer for sedentary adults. The final chapter suggests an excellent reasonable exercise regime for adults who don’t have field to plow.
Visit http://www.youtube.com/watch?v=Bmc0ERKfjP0 for a fine video presentation that John Ratey made on his beliefs and book.
Ratey, J. with Hagerman, E. (2008) Spark: The Revolutionary New Science of Exercise and the Brain. New York: Little Brown.