Your brain does not switch off when you space out — the default mode network

🧠A resting brain is not a brain switched off

In 2001 Marcus Raichle and colleagues published “A default mode of brain function” in PNAS. At a time when imaging work looked only at the regions that lit up during a task, the paper set out the opposite finding: there is a consistent set of regions whose activity goes down the moment a task begins. Sitting still is those regions’ baseline — their default mode — and turning outward to the world quietens them. That is where the name comes from. Resting is not the brain going dark. It is the brain going somewhere else.

🔁Ten minutes after learning decided what was left seven days later

In 2012 Michaela Dewar and colleagues at the University of Edinburgh reported a short experiment in Psychological Science. Participants listened to a story. One condition then sat quietly for ten minutes; the other spent the same ten minutes on a spot-the-difference task. Recall differed 15 to 30 minutes later — and, more surprisingly, the difference was still there seven days on. In a second experiment nobody was asked to recall the story in between, and the result held anyway. The memories had not been kept alive by rehearsal. They had settled during the rest.

🎧Which is why a session stops at ten minutes

Ten minutes of listening, then five minutes off at the least. That was our rule for a decade before there was a paper to point at — short and often beat long and rare, and we knew it from watching learners rather than from imaging. The research puts a floor under it. Following speech above normal speed is not cheap either; even with nothing wrong with the audio, the brain is spending real energy the whole time ([[listening-effort]]), and the tank is not bottomless. So the demo player on this site stops on its own at ten minutes instead of letting you push on, and the thirty-day routine is built out of short sessions rather than long ones ([[wav-speed-listening]]).

📑What has been shown, and what has not

Rest is an easy subject to oversell, so here is the boundary drawn explicitly.

• ShownA short period of wakeful rest immediately after learning raised recall of that material — both 15 to 30 minutes later and seven days later. (Dewar et al., 2012 · Psychological Science)
• ShownA consistent set of brain regions increases its activity when a person is doing nothing in particular. Later work has repeatedly linked that state to self-reflection and to the settling of memory. (Raichle et al., 2001 · PNAS)
• Not shownAny claim that spacing out multiplies your creativity by some factor. The direction of the benefit is observed again and again; its size varies widely from person to person and task to task.
• Worth knowingThe default mode is not always benign. The same circuitry has been reported in connection with rumination — turning a worry over and over. A break is time left empty, not time to think in.

💡How to spend the five minutes between sessions

Take the earphones out and stay where you are. Look out of a window, drink some water, do something that only your hands are needed for. A short nap is fine. There is one thing not to do: take in new information. Video, feeds and messages can wait five minutes. Two to four rounds a day of ten minutes on and five minutes off, and more of what you heard that day is still there at the end of it.