If you struggle to remember names and numbers or frequently fail to follow the plot of a film, help could be at hand.

Scientists say the problem is that you know too much – and you need to declutter, or spring-clean your mind.Experiments show that the memory lapses that come with age are not simply due to brain slowing down.

Instead, they can be blamed on the well-used brain finding it more and more difficult to stop irrelevant information interfering with the task in hand.

The first step in the study was to compare the working memory of the young and old. Working memory involves holding information in mind while manipulating it mentally.

Examples in everyday life include retain plots of films and books to understand or predict what will happen next and following the thread of a conversation while working out how you can contribute to the topic.

In the context of the study, it involved giving the volunteers groups of sentences and asking them to work out whether each line made sense – and to remember the last word of each sentence.

Overall, the younger people, who had an average age of 23, did better, the Quarterly Journal of Experimental Psychology reports.

The Canadian researchers then did a second experiment to see what was hindering the older volunteers, who had an average age of 67.

This involved being shown pictures of eight animals and being asked to memorise the order in which the creatures appeared.

The volunteers were then shown dozens of the pictures and asked to click on their computer mouse when the first animal in their memorised sequence occurred, then the second and so on.

The older adults found it more difficult to progress, suggesting the previous picture was stuck in their mind.

Mervin Blair, of Montreal’s Concordia University, said: ‘We found that the older adults had more difficulty in getting rid of previous information.

‘We found that that accounted for a lot of the working memory problems seen in the study.’

A third study confirmed that the memory problems were not simply due to a simple slowing down of the mind.

Mr Blair, a PhD candidate, says that the older mind appears to have trouble suppressing irrelevant information. This makes it more difficult to concentrate on the here and now.

For those who have trouble remembering, he suggests relaxation exercises to declutter the mind.

‘Reduce clutter, if you don't, you may not get anything done.’

Keeping the mind young, through learning a language or musical instrument can also help.

He added that younger people can also fall foul of memory lapses caused by a failure to suppress extraneous information, with sleepless nights making it harder for the brain to function properly.

Previous research has found that the part of the brain that keeps embarrassing thoughts in check also weakens with age, leading to people losing some of their inhibitions.

In other words, outspoken old people aren't being rude - they just can't hold their tongues.

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