Registering a memory for the long haul doesn't happen all at once, according to new studies of how people learn perceptual and motor skills. Instead, building memory is a three-pronged process that rests on sleep.
First, knowledge accrues during training and dips immediately afterward. A good night's sleep then revives much of what was forgotten, the researchers find. Finally, recalling the learned skill the next day destabilizes the memory of it, setting the stage for an individual either to reinforce prior knowledge or lose it.
These findings, published in the Oct. 9 Nature, contrast with the long-standing psychological theory that lasting memories essentially form all at once and don't require sleep.
"Memory seems to be a process of storage and restorage," says neuroscientist Karim Nader of McGill University in Montreal in a commentary published with the new studies.