Demis Hassabis, co-author of the study, said it was “a small step towards the idea of mind reading, because just by looking at neural activity we were able to say what someone was thinking”.

The experiment, published in the journal Current Biology, is significant for neuroscience as it shows for the first time that memories are laid down in specific structures or patterns in the hippocampus, a brain region that is crucial for navigation, memory recall and imagining future events.

Four volunteers navigated around a room in a computerised virtual reality game while the researchers examined their hippocampus with an fMRI scanner. The researchers had spent time with the subjects “training” the analytical software to recognise their spatial memories.

“Surprisingly, just by looking at the brain data we could predict exactly where they were in the virtual reality room,” said Eleanor Maguire, project leader.

“In other words we could ‘read’ their spacial memories.”

But Dr Hassabis said it would be at least 10 years – and probably much longer – before the technique could be used in forensic investigations, for example to tell whether a suspect was lying about whether they had been at a crime scene.