The Resilient Brain: BA/BPS Lecture 2011

Which of us has not at some point wrestled to remember the name of a famous film star whose face we can quite clearly picture? Or walked into a room to fetch something, only to forget what it is we went there for?

These so-called 'senior moments' do occur in all of us, but become increasingly common as we get older. However, Lorraine Tyler, Professor of Cognitive Neuroscience at the University of Cambridge, argues that to believe that cognitive decline is inevitable is dangerous and outdated.

Outdated because substantial research now tells us otherwise; dangerous because negative attitudes can in themselves impact on cognitive performance and health: a 39-year-long study by Becca Levy and colleagues at Yale evaluated 18- to 48-year-olds for their attitudes to older people, and found that those with negative attitudes were significantly more likely to have early heart attacks and strokes.

So how can we convince society and individuals that age does not have to be something to mourn?

Professor Tyler gave her answer in this year's BA/BPS Lecture, which was held at the Royal Society, London, on Thursday 22 September 2011.

Tyler showed us an animation of a healthy brain slice as it passed through the decades. There were nervous gasps from the audience as we watched the staggering reduction in grey matter between the ages of 20 and 80. And if any of those in the younger bracket were feeling like this was all a distant concern, they were soon put to rights as Tyler pointed out that brain shrinkage has already started by the time you reach 30.

'Don't panic though!' she urged us. 'It is what you can do with your brain that matters, not how much of it you have.' There is also a lot we can do to stave off the effects of age.

A key feature of the ageing brain is the huge variability both within and between individuals. Because some regions of the brain are more prone to age-related loss of cells than others, some cognitive functions are more vulnerable to the passing years. Verbal and numeric ability are extremely resilient and often even improve, while factors such as processing speed, problem solving and verbal memory are more susceptible to the effects of age, and most of us can expect these functions to decline to some extent.

This is where individual differences come in though. Some people over 80 can perform in line with much younger people, even in cognitive functions that typically decline. A parallel resilience can be seen in the brain itself, and Tyler demonstrated this with pictures of very young-looking brain slices from a 115-year-old woman.

Tyler proposes that we consider a different take on ageing. Yes, chronological age matters, but brain health matters much more. The brain is capable of reorganising its functions and compensating for lost neurons: it remains adaptive and reactive. For example, older adults who perform well on cognitive tasks not surprisingly have more grey matter than those who perform poorly, but they are also more likely to use both sides of their brain.

So what can we do to improve brain health and function? Some have argued for cognitive training, but according to Tyler for every positive study there is a negative one and the jury is still out. Far more compelling is evidence of the link between regular exercise, cardiovascular health, brain volume and cognitive performance. Kirk Erikson showed this year that compared to stretching, a year of aerobic exercise led to greater levels of hippocampal function and better working memory and other work shows that exercise actually stimulates neurogenesis, the development of new neurons.

We cannot avoid getting older, Tyler says, but there are evidence-based steps to build resilience in the brain and thus the mind. Keep exercising and keep the mind engaged. 'Get out there!' concluded Tyler. 'Believe the science and change society's views.'

This report was written for The Psychologist by Catherine Loveday from the University of Westminster.