It's not much fun contemplating mental decline in old age. The normal assumption is that's all downhill, even for those avoiding dementia, Alzheimer's, and other brain diseases. Therefore it was with great pleasure that I read a new book by neuroscientist Elkhonon Goldberg, The Wisdom Paradox: How Your Mind Can Grow Stronger as Your Brain Grows Older (London: Free Press, 2005).
Yes, the subtitle tells it all. There is hope for us oldies!
Goldberg reviews the functions of different parts of the brain and evidence from people with specific brain injuries. He comes up with a revised picture of the role of the hemispheres. He argues that the right hemisphere is used for acquisition of new things and the left hemisphere for well-established processes. So when learning language as a child, the right hemisphere is engaged, but after language has been acquired, it is mainly processed through the left hemisphere.
More generally, the left hemisphere is for pattern recognition and is used far more for things we do a lot of. For a given task, an expert uses much less energy (kilojoules expended in the brain) than a novice. That explains why the more writing we do, over time the easier it gets.
What's important is that the well-entrenched patterns in the left hemisphere - the ones developed through extensive use - are especially resistant to ageing. In fact, they can compensate for declines in memory and attention. Goldberg gives examples of elderly artists and national leaders who continued to function adequately despite evidence of serious brain dysfunction.
For us ordinary souls, there is evidence that elderly workers can maintain the same productivity as younger ones. Tacit knowledge is well developed in older people and is especially resistant to decline.
It's easy to see the value of acquired pattern recognition skills in academic work. After marking hundreds or thousands of essays over the years, it becomes easier to mark the next one: often a glance at the first page or just the first paragraph is enough to indicate its strengths and weaknesses. (Of course we always read every word!) After supervising many theses, it becomes easier to conceptualise a topic as a thesis, something that is incredibly hard for many students doing their own thesis.
Goldberg's good news is that brain function can be maintained and indeed improved. New brain cells are created throughout our lives. The more we use any part of the brain, the more developed and efficient it becomes doing that particular thing, whether it's strategic planning or doing a crossword.
The key is to work at it. A lifetime of active mental functioning is the best protection against decline in old age. Furthermore, cognitive training is good for the brain at any age, and can reinvigorate elderly brains. Sudoku is good for you!
Physical exercise is good for the brain too, maintaining blood flow and helping prevent death of brain cells.
Intellectuals are especially well placed to maintain a strong brain in old age, because they regularly flex their minds. But even those who think for a living can benefit from additional mental exercise. That's because much of our work is quite specialised; a general mental tone-up can help maintain overall brain function.
Think of a tennis pro, for example, who should be very fit from all that exercise playing tennis. But tennis is a very specialised physical activity. Even the pro can benefit physically from weight training, running, swimming and stretching.
Similarly, as intellectuals we can get very good at deconstructing texts or reading uni handbooks but might also stimulate our brains on tasks such as learning a new language, drawing portraits or playing computer games. Or if you want to be more practical, you can memorise all your students' names, learn all the exits in building 19, add up your marks by hand, and recite Shakespeare to yourself during boring meetings.
Goldberg has developed computer-based mental exercises to stimulate ageing brains. One of the best things about mental exercise for the elderly is that it builds self-confidence. Goldberg's book can help with self-confidence too!
16 January 2006
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