What it is
Cognitive shuffling asks you to occupy your imagination with a sequence of unconnected images. Not a calm scene, not a story, not counting — a deliberately random stream: a kettle, a giraffe, a doorknob, a beach.
It was developed by Luc P. Beaudoin, a cognitive scientist, who named it serial diverse imagining. The everyday term is the cognitive shuffle, and the app built around it is Somnio — though you do not need an app, which is part of the appeal.
Why it might work
The reasoning draws on what the mind does naturally at sleep onset. As you drift off, thinking becomes loose and associative: fragmentary, disconnected images that do not add up to anything. Those are hypnagogic experiences, and they are a normal feature of falling asleep.
The proposal is that the relationship runs both ways. If disorganised imagery is a signature of falling asleep, deliberately producing disorganised imagery may act as a signal to the sleep-onset system that it is safe to proceed — that nothing coherent or urgent is being processed.
There is a second, simpler effect that may do a lot of the work. A worry loop is a narrative. Narratives require continuity. Interrupting yourself every three seconds with an unrelated object makes narrative impossible. Whether or not the sleep-signal theory holds, the loop-breaking is real and immediate.
How to do it
- Pick an ordinary, emotionally neutral word. “Lantern”, “bicycle”, “harbour”. Avoid anything connected to what is worrying you.
- Take the first letter. For “lantern”, that is L.
- Imagine things beginning with that letter, one at a time, a few seconds each. A ladder. A lemon. A lake. A lion.
- Actually picture each one. Seeing it matters more than naming it — the imagery is the active part.
- Move to the next letter when you run dry. A: an apple, an anchor, an arm.
- Do not build a story. If the images start connecting, break it deliberately and jump somewhere unrelated.
Most people either fall asleep or lose track partway through. Losing track is the intended outcome, not a failure of technique.
What the evidence actually shows
Honest answer: promising, limited, and nowhere near the level of CBT-I.
The most cited work is a 2016 pilot study with 154 university students, comparing serial diverse imagining with structured problem-solving. Both appeared to help; the shuffle was reported as easier to apply while lying in bed, which is a meaningful practical advantage even when effect sizes are similar.
But this is a pilot, in students, with self-reported outcomes. It is not a large randomised trial in people with chronic insomnia, and it should not be presented as one. What can fairly be said: the mechanism is plausible, the technique is free, it carries no risk, and a reasonable number of people find it helps. That is a decent case for trying it and a poor case for claiming it is proven.
Who it will not work for
If you have aphantasia — the inability to form voluntary mental images — this technique has nothing to work with. Estimates suggest somewhere around 1–4% of people are affected, many of whom have never heard the term and simply assumed “picture an apple” was a figure of speech.
If that is you, use verbal or sensory alternatives instead: listing words in a category, the body scan, or 5-4-3-2-1 grounding based on what you can actually hear and feel.
When to reach for it
It is at its best against narrative rumination — replaying conversations, rehearsing arguments, mentally drafting emails. It is weaker when the problem is physical arousal; for a pounding heart or restless legs, start with the body first.
Sources
- Beaudoin, L. P. — serial diverse imagining (cognitive shuffle), including the 2016 pilot comparison with structured problem-solving in 154 students.
- American Academy of Sleep Medicine — clinical practice guidance on chronic insomnia and CBT-I as a first-line approach.
- National Institute of Mental Health — anxiety disorders: signs, symptoms and treatment options.