Cognitive shuffling: how to do it, and what the evidence says

Printable letter card

Keep this by the bed so you don't need your phone to pick a letter. Choose any letter at random each time.

How cognitive shuffling is linked to serial diverse imagining

Cognitive shuffling is linked to Luc Beaudoin’s serial diverse imagining: his 2013 paper on it is filed under the keyword “the cognitive shuffle”. The paper proposes that deliberating, ruminating or focusing on your own arousal interferes with falling asleep, and that some kinds of incoherent mentation make falling asleep easier; serial diverse imagining, a family of techniques derived from that idea, is expected to speed it up. The paper presents no new data and was not peer reviewed.

A busy mind is a common part of insomnia:

A 2023 systematic review of insomnia models notes that most people with insomnia name cognitive arousal, rather than bodily arousal, as the main cause of their sleep problems, and describes a “racing mind” as the crux of the insomnia experience.

What the studies show

A study of serial diverse imagining, the technique cognitive shuffling is linked to, was accepted as a poster abstract for a sleep conference:

In a study accepted as a poster abstract for the SLEEP 2016 meeting, 154 university students (137 of them women) who complained of too much mental arousal before sleep were randomly assigned to serial diverse imagining, structured problem-solving done before bedtime, or both. Pre-sleep arousal, sleep effort and sleep quality improved from the start of the study, and the authors concluded that the imagining task was as effective as structured problem-solving.

In that study an app played recordings of fairly concrete words one at a time, 8 seconds apart, and the person created and held a mental image of each word until the next one.

The imagining group used SomnoTest, a research version of the mySleepButton app from CogSci Apps Corp., and the study was accepted as a conference poster abstract.

Two limits are worth knowing. The students were chosen because they complained of too much mental activity before sleep; the abstract does not say any of them had been diagnosed with insomnia. And the study compared the technique with another active method rather than with doing nothing, so it can't say how much of the improvement the imagining itself caused. An older experiment with people with insomnia tested a related idea, imagery as a distraction:

In a one-night experiment with 41 people with insomnia, those taught to distract themselves with an interesting, engaging imagery task fell asleep sooner and had less frequent and less distressing thoughts before sleep than those given no instructions.

The letter routine on this page is one way to get random words without a device; in the 2016 study the words came from recordings played by an app.

Why we suggest keeping the phone out of bed

Shuffle apps exist; the study above used one. Our suggestion is still to leave the phone out of bed, in line with stimulus control, whose instructions in the AASM guideline keep the bed for sleep:

Stimulus control, as the AASM guideline lists it: go to bed only when sleepy; get out of bed when unable to sleep; use the bed and bedroom for sleep and sex only; wake up at the same time every morning; and do not nap in the daytime.

If you have shuffled for a while and are no closer to sleep, get up and come back when you feel sleepy: the steps are on what to do when you can't sleep. If worry about sleep is what keeps your mind going, see sleep anxiety; for other methods and their evidence, see how to fall asleep fast.