One of the key elements of memory – how we store and retrieve words according to what they mean – has been unravelled by analysing electrical signals from people’s brains while they recalled lists of words. Although the discovery cannot identify the individual words being filed, which could effectively make a very basic form of mind-reading possible, it does for the first time reveal the electrical circuitry vital for storing words according to what they mean, rather than where they came in a sequence, for example.