Yes, your brain will probably experience a ‘great restructuring’ after you turn 40

We know that the brain undergoes significant structural, functional and metabolic changes with age, with associated alterations in cognition and behaviour. A systematic review was recently published in the journal Psychophysiology, in which researchers from Australia looked at 144 studies and summarised how the connectivity of the human brain changes over our lifetimes.

They found that after the age of 40, the brain starts to undergo a rewiring that results in diverse networks becoming more integrated and connected. They suggest that this results in less flexible thinking, lower response inhibition, and reduced verbal and numeric reasoning.

While this may be compelling, it is worth noting that these types of studies are based on results from an imaging technique called functional MRI. These allow neuroscientists to observe the parts of subjects’ brains that ‘light up’ in response to stimuli or when simply at rest.

However, we can’t really be sure that these are responsible for the changes in cognition that we see at the time – there might be a link, but it is difficult to prove. Looking at the data from the study, the ‘restructuring’ is fairly gradual, not a dramatic step-change each decade as might be suggested.

So maybe there is not a ‘great restructuring’, and we don’t know exactly how this translates to cognition, but this review adds weight to the finding that there are changes in the brain that occur with ageing.

Read more:

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• Is it true that we only use 10 per cent of our brain?

Asked by: Billy Evans, Newport

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