This is your bedtime ritual. After playing a tune at 528 Hz – a frequency billed to ‘release inner conflict and struggle’ – you settle into a simple weightlifting routine. Then you drink a casein shake, put on your headphones and turn on the music player. For the next several hours, the player will recite a list of words in French for you to absorb while you sleep, as you lay your head on a pillow that smells faintly of vanilla. In eight or preferably nine hours, you will wake up slimmer, energised and slightly more fluent at French.

It is difficult to say exactly how popular any of these practices are. The two-hour anti-anxiety soundtrack alone has been played on YouTube over four million times to date; the five-hour first instalment of Learn French with Vincent While You Sleep, nearly two million. Enough to suggest the existence of a small but thriving cottage industry designed to increase your productivity while you are unconscious.

Everything serves a function. The music: to predispose your brain waves to receive subliminal stimuli. The casein and resistance training: to trigger your metabolism to burn more calories while at rest. The vanilla scent: to promote recall of the word lists you had previously studied while standing perhaps downwind of a sponge cake.

These methods, if not quite scientific, are sometimes at least science-adjacent, relying as they do on the findings of genuine studies – for instance, on the role of sounds and smells as associative memory aids – that have filtered in partial or garbled form onto the pages of lifestyle magazines. Their origin dates back to the 1920s, through early devices such as Alois Benjamin Saliger’s ‘psycho-phone’, a phonograph designed to play recordings on wax cylinder at set times of the night. An early advertisement for the psycho-phone boasts its ability to ‘lay hold of your unconscious mind during sleep, when all interference of the intellect and environment are in abeyance’, and ‘get result overnight that would take months or years to accomplish’. In 1931, a similar device was featured in Aldous Huxley’s Brave New World, where the technique known as ‘hypnopaedia’ was used to brainwash rather than educate the populace.

The crude claims made by the inventor of the psycho-phone regarding the brain’s ability to acquire new information wholesale during sleep were discredited in the 1950s in a series of experiments measuring brain activity. However, the idea that some form of subconscious learning is not only possible but also easily attainable has made periodic comebacks, dragging with it a series of other ‘while you sleep’ activities: lose weight, play the market and so forth. Like most other prescriptions of the world of self-help, these claims are symptoms of a historically recurring anxiety. In post-industrial capitalist societies, to fall behind the curve of personal improvement and progress has a range of negative social consequences, including loss of employment and social status. Always, it seems, what stands between the (predominantly white middle-class) individual and success are willpower and a more rational use of one’s time and resources. It is perhaps inevitable, then, that these activities should expand into the domain of rest and sleep.

Ten years ago, subliminal conditioning and learning featured in a series of videos by square-jawed life-coach-supremo Tony Robbins. These days they are packaged in the form of YouTube videos and apps that fit on your phone. The connection these create is far more intimate than the clunky, hardly portable psycho-phone, or the vinyl records that could only be played on the lounge stereo. We are moving into a new phase in which these fringe activities sit alongside – and might gradually merge with – the ever-expanding world of fitness wearables and psychometric trackers, as well as overlap with the critical long-term trend towards the desocialisation of adult learning.

It can be exhilarating to have so many video courses and history podcasts at our disposal, so much knowledge presented in a readily accessible way. On the flip side, however, are disruptive edtech and the repackaging of old critiques of dominant education models in order to sell a new kind of university: dispersed, long-distance, horizontal – ultimately, a university without people. And what is learning in your sleep if not an extreme version of the empty classroom? You are not even all there yourself.

Ironically, since the days of Saliger, neuroscientists have come to understand that learning is something that happens during sleep anyway: it is at this time that the brain reflects on the day’s events and distributes new memories stored in the hippocampus to the regions devoted to long-term storage. But if you would still like to try to learn to read Balzac in time for breakfast, by far the most elegant app is billed as the Learn French Sleep Learning System and is available on iTunes for $20.99. Developed by a certified hypnotherapist, the recorded material lasts nearly four hours and does not feature a single word of French.

Image: Ana Sofia Guerreirihno / Flickr