The question “Why is it impossible to stop thinking, to render the mind a complete blank?” was posed to professor of neurology and cognitive science Barry Gordon of the Johns Hopkins University School of Medicine. The following is a shortened version of his answer. The complete answer can be found in the November/December 2012 issue of Scientific American Mind…..
Forgive your mind this minor annoyance because it has worked to save your life – or more accurately, the lives of your ancestors. Most likely you have not needed to worry whether the rustling in the underbrush is a rabbit or a leopard, or had to identify the best escape route on a walk by the lake, or to wonder whether the funny pattern in the grass is a snake or a dead branch. Yet these were life-or-death decisions to our ancestors. Optimal moment-to-moment readiness requires a brain that is working constantly, an effort that takes a great deal of energy. Such an energy-hungry brain, one that is constantly seeking clues, connections and mechanisms, is only possible with a mammalian metabolism tuned to a constant high rate.
Constant thinking is what propelled us from being a favorite food on the savanna – and a species that nearly went extinct – to becoming the most accomplished life-form on this planet. Even in the modern world, our mind always churns to find hazards and opportunities in the data we derive from our surroundings, somewhat like a search engine server. Our brain goes one step further, however, by also thinking proactively, a task that takes even more mental processing.
Our primate heritage brought us another benefit: the ability to navigate a social system. As social animals, we must keep track of who’s on top and who’s not and who might help us and who might hurt us. To learn and understand this information, our mind is constantly calculating “what if?” scenarios. What do I have to do to advance in the workplace or social or financial hierarchy? What is the danger here? The opportunity?
For these reasons, we benefit from having a brain that works around the clock, even if it means dealing with intrusive thoughts from time to time……..Scientific American Mind November/December 2012