Oh, the seductive lure of mental autopilot! Whether we realize it or not, much — perhaps even most — of our mental life occurs on autopilot, and we rely increasingly on autopilot as we age. Our mental autopilot is the product of our experience and it enables us to perform complex mental feats effortlessly and efficiently.
Whether you are a doctor treating a patient, a professor teaching students, or an engineer designing a machine, the odds are that a great deal of your professional activities — no matter how rigorous they may appear to an outside observer — are routine. You practice well-rehearsed professional skills smoothly and effortlessly. Most of the maladies diagnosed by an experienced physician on any given day are like the maladies encountered by the same doctor the day before. Most of the lectures given by a tenured professor this year are only slightly modified versions of the lectures given by the same professor the year before, and so on. Is there anything wrong with this? Not for the patients and not for the students. They both benefit from the experience and expertise of the aging professionals in whose hands they have placed their health or their education. The mental efficiencies behind the smooth and precise performance by an experienced expert are the fruit of years of professional growth and accomplishment. But what may be good for an aging expert’s performance or for his clients is not so good for his own aging brain.
Recent neuroscience research has shown that the human brain is more amenable to change than was thought to be the case even a few decades ago. The brain’s capacity for change is sometimes referred to as “neuroplasticity.” Today we know that, contrary to the assumptions that had dominated neuroscience for decades, the brain retains its capacity for neuroplasticity throughout the human life span, even in advanced age.
Neuroplasticity is a major mechanism of the brain’s ability to enhance its performance, to protect itself against the detrimental effects of aging, and to repair itself following brain injury. This is accomplished through the ongoing growth of new small vessels providing blood supply to the brain, and new connections between nerve cells (synapses, and even new nerve cells) in certain parts of the brain. This is terrific news. What makes the news even better is that neuroplasticity is, to a considerable degree, under environmental control. Both the extent of effects of neuroplasticity and the location in the brain that these effects are manifest depends to a significant degree on the nature of our mental activities. The effects of mental activities on the brain can be quite robust, changing its microstructure and even its gross neuroanatomy in observable, measurable ways. This has been demonstrated with a variety of research tools, including state-of-the art neuroimaging devices such as magnetic resonance imaging (MRI).
There is a catch, however; in fact, three interrelated catches.
First, in order to be truly beneficial in stimulating the mechanisms of neuroplasticity, the mental activities have to be challenging. They have to be difficult enough to be manageable but effortful. To benefit your brain, you need to do precisely that which your arsenal of mental autopilots allowed you to escape: strain your brain.
Second, to benefit your brain, your mental activities need to be novel. You have to brave outside your comfort zone. Why? Because in order for the neural networks to be formed or modified, the existing ones must be unable to do the job. A simple analogy: For the new grooves to form in the sand, the existing ones must be unable to accommodate the flow of water.
These notions may sound self-evident, but it is not uncommon for us to avoid mental effort just as we often tend to avoid physical effort. And over the years of giving lectures to various general audiences I have noticed a peculiar phenomenon: People often enjoy hearing what they already know more than being exposed to truly novel information or ideas.
Third, to really benefit your brain, your novel and effortful mental activities must also be diverse. This is the case because the brain is a highly diverse, specialized organ. Different parts of the brain are in charge of different mental activities, just as different muscle groups are in charge of different physical activities. The more diverse your activities, the more of your brain will benefit from the effects of experience-driven neuroplasticity.
While neuroscientists have begun to obtain evidence in support of these three points only recently, some of the greatest minds in recent history had figured it out for themselves intuitively. Albert Einstein used to play the violin and navigate his sailboat for recreation —activities far removed from his work as a theoretical physicist. Winston Churchill used to paint acrylics during his spare time. He was not only a great statesman but also an exceptional writer who received the Nobel Prize for literature. Diverse mental activities again! Another Nobel Prize winner, Lev Landau, one of the 20th century’s most important theoretical physicists, took pride in not having any physics books in his home library — only literature and books on subjects far removed from physics, like history and the arts, according to his widow’s memoirs.
What are the implications of these three points: challenging, novel, and diverse? One of the implications is that no single type of mental activity will do the job of keeping your brain fit by itself. We hear about the benefits of crossword puzzles or Sudoku. Each of these is useful as an ingredient among many diverse activities, rather than one performed repetitively by itself.
How does one diversify one’s mental life? There are many ways of doing it, and it is impossible to anticipate every specific situation or set of life circumstances. There are various paper-and-pencil activities like Sudoku and crossword puzzles, there are a growing number of game-like cognitive-exercise software packages, and there are intellectual pursuits like adult learning programs. Finally, there is life with all its opportunities to learn and not to be bored. Ultimately, it is a matter of attitude: Curiosity is as great an asset as intellect or beauty. And if you discover the joy of mental exertions like a runner discovers the joy of physical exertion, you will have come a long way towards having brain fitness for life.