If the idea of going to sleep with a cumbersome headset doesn’t appeal, Miriam Reiner at the Technion Institute of Technology in Haifa, Israel may have a more attractive solution. She hopes to use a form of neurofeedback, which allows subjects to control their neural activity while awake. In her setup, an electrode attached to the subject’s head feeds into a simple computer game, in which the subject is advised to drive a car with the power of their thoughts.
When the electrode records the right frequency of brainwaves, normally associated with memory consolidation during sleep, they accelerate; when they don’t, it slows down. It typically takes just a few minutes for the subjects to start revving up the right brainwaves – and the change in mind set is palpable, says Reiner. “I feel kind of relaxed – like when you’re in a garden or walking along beach. It’s just like being in a serene beautiful place.” The idea is to kick-start memory consolidation straight after learning, which then gives the sleeping brain a head-start as it sets about reorganising the day’s events. “You create a seed that then grows during the night,” says Reiner.
Play a tune
To test the impact on learning, her subjects first learned a complex sequence of finger movements – a little like learning to play a tune on the piano – before taking 30 minutes of neurofeedback. The benefits were immediate – straight after the training they were about 10% better than the controls, suggesting the computer game really had begun to stabilise their memories as if they were actually asleep. Importantly, the improvements continued to grow as they were tested throughout the following week, supporting her theory that neurofeedback could help memories to blossom as you sleep.
Needless to say, we will need to see bigger trials with many more subjects before these techniques should be recommended for everyday use. Since the experiments have so far used somewhat artificial tests of learning and memory, it would also be useful to see how they fare on more useful tasks; Reiner is beginning to take a few steps in this direction by testing whether her neurofeedback can help students learn the guitar. Diekelmann also thinks that we need to confirm that these memory hacks don’t have unexpected consequences. “If you enhance one set of memories, maybe you’d impair another set,” she says.
And we shouldn’t shy away from the problems highlighted by fiction like Brave New World and The Simpsons, she says. Although she doesn’t think that these methods could be used for brainwashing people against their will, she thinks we still need to question whether it would be right to start manipulating their children’s memories, for instance, in these ways. “Sleep is a vulnerable state.” But she’s keen to stress that these potential issues shouldn’t deter interest in sleep learning. “It’s very worthwhile. We just need to use it as responsibly as possible.”
Once those questions have been addressed, there shouldn’t be too many practical hurdles for people who wish to use the techniques for themselves, says Diekelmann. Many of her students and colleagues have already found that sensory cues during sleep can help them swat-up for exams. “It’s very easy to apply,” she says. And you can now buy EEG kits that work with your smartphone, potentially opening the door for games that help you boost memory consolidation. Even the hardware for certain forms of tDCS became commercially available last year, which could lead to kits designed to improve sleep learning.
Further evidence will be needed to show that the commercial kits can provide the benefits seen in the laboratory experiments, but Born is optimistic. “I think it’s just a matter of time before it is used as a cognitive enhancer,” he says.
At the very least, the research could change the way we view this often under-appreciated part of our lives. Sleep tends to be considered an unnecessary down-time that we try to conquer with coffee or Red Bull; we are all driven by the need to squeeze the day for every last drop of productivity. But we may take more time to catch 40 winks if we know that the most profitable part of the day really could involve doing nothing at all.