Our brains compensate for decline as we grow older by recruiting other areas

To my astonishment certain aspects of my memory have improved not diminished as I’ve grown older. I’ve often wondered why as we can’t grow new brain cells, so what’s happening?

Cambridge scientists have come up with a possible explanation. They’ve found our brains can compensate for age-related deterioration by recruiting other areas to help with brain function and maintain cognitive performance.

Instinctively I feel that’s what’s happening to me. But why does it happen for some older people and not for others – is there something special about these people?

As we age, our brain loses nerve cells and connections resulting in a decline in brain function. We don’t know why some people maintain better cognitive function and can protect themselves from such decline.

Cambridge University scientists collaborating with colleagues at Sussex University have shown that when the brain recruits other areas, it improves performance specifically in the brains of older people.

Study lead and Alzheimer’s Society Dementia Research Leader Dr Kamen Tsvetanov explains our “fluid intelligence” – our ability to solve abstract problems – ebbs as we get older, but not in everyone.

Are these people therefore better at recruiting other areas of the brain to overcome decline? The Cambridge team looked at imaging data from 223 adults aged between 19 and 87 who had been recruited by the Cambridge Centre for Ageing & Neuroscience.

The volunteers were asked to identify the odd one out in a series of puzzles of varying difficulty while being scanned in an fMRI scanner that tracks brain activity by measuring blood flow. The scientists found two areas with greater activity in the brains of older people, which also correlated with better performance of the task.

One of these areas was the cuneus, a portion of the occipital lobe at the rear of the brain. It’s a region where task performance is strongly correlated with the older volunteers.

This brain region is usually good at helping us stay focused on what we see, so older people might be using it as a strategy to make up for their weak visual memory.

Cambridge University’s Dr Ethan Knights said: “Now that we’ve seen this compensation happening, we can start to ask questions about why it happens for some older people but not others, and in some tasks, but not others.

“Is there something special about these people – their education or lifestyle, for example – and if so, is there a way we can intervene to help others see similar benefits?”