How the brain stores memories

Memory loss is gradual but, unlike computers, we have inbuilt backups

An older woman opening a front door to leave the house
Doorways: if you can’t remember an address, other sights and sounds can trigger memory. Photograph: Alamy Stock Photo

Every week there is a new dementia study, raising hopes that we can find a way to halt memory loss. Interestingly, in any form of dementia our memories don’t vanish immediately but fade gradually – our memory systems have a property known as ‘graceful degradation’.

In a computer, each item of information is stored in a specific location. If part of the memory or hard drive becomes corrupted, a specific fact or image is lost instantly. The brain works differently by splitting up memories into overlapping patterns across a network of thousands and millions of neurons. As memory fades, there is a gradual deterioration in the ability to recall efficiently.

We have the added benefit of many more memory triggers if we want to recall, say, a specific address. Any element of the memory can bring it back - from a photograph, to the sound of a squeaky gate or a dodgy paving stone underfoot. Compared to a computer, it’s a much more resilient way of storing valuable information – probably a good thing since you can’t back up your brain.

Dr Daniel Glaser is director of Science Gallery at King’s College London. Listen to this week’s podcast at