It can be jarring to catch yourself staring into space when you were meant to be doing something. Zoning out happens to everyone, even though the exact cause has been unclear.
New research helps map what the brain is doing in these moments. In a study published in Nature Neuroscience, 26 participants completed brain scans after a restful night of sleep and after a night of sleep deprivation.
As expected, the sleep-deprived group performed worse on tasks that required focus than those who were well rested.
Here’s the twist: some participants showed no brainwave change to certain stimuli, pointing to brief lapses in attention. During those lapses, researchers observed an increase in cerebrospinal fluid flowing out of the brain. When attention returned, the fluid flowed back in. Pupil size narrowed and neuronal activity shifted during these episodes, too.
The team concluded these brain–body shifts are “tightly orchestrated” to create that not-there feeling. In effect, the body may be trying to nudge itself toward sleep for a quick reset so you can keep going.
So why does this happen, and what if zoning out is frequent? Neurologists explain.
Why does your brain zone out sometimes?
That’s still being explored. “‘Zoning out’ might be another term for ‘microsleep’—short periods of reduced consciousness and frank sleep so brief they escape an individual’s awareness,” says neurologist and sleep medicine physician Dr W. Christopher Winter.
It’s more complex than that, though. “We still don’t know why we sleep and, if you ask two different neurologists, you will often get two different answers,” says neurologist Dr Clifford Segil.
Based on these findings, zoning out may be necessary for brain health, Dr Segil says. It may let neurons rest and help the neurotransmitters in circuits that keep you awake, focused and active reset.
It could also be the brain trying to catch up after a poor night, says psychiatrist and sleep medicine physician Dr Alex Dimitriu. During deep sleep, the brain’s glymphatic system “washes out” leftover by-products from the day. “When people get insufficient sleep at night, it is possible that episodes of zoning out during the day may be the brain trying to catch up on processes that were not finished during the night,” he says.
What does it mean if you zone out a lot?
Researchers don’t know for sure, but a few themes stand out. You may simply need more sleep, says Dr Winter. That’s unlikely to be the only factor, though.
Zoning out “may indicate you need more food or better nutrition,” says Dr Segil. “Sleep and nutrition are both equally important to maintain good focus.” It can also reflect the brain consolidating memories, feeling sleepy or feeling overwhelmed by what’s around you, he adds.
Less commonly, frequent zoning out can signal brief seizures or complicated migraine, Dr Winter says. If episodes are regular, prolonged, or come with confusion, headache, vision changes or jerking movements, see your GP.
Is zoning out bad for you?
Zoning out isn’t ideal when you need sharp focus, and it’s risky during driving or any hazardous task, notes Dr Winter.
That said, brief lapses of attention are usually harmless. “Zoning out in isolation may be healthy and is unlikely in isolation to herald any new medical diagnosis,” says Dr Segil.
Sometimes, though, frequent episodes point to something else. In older adults it can be a sign of dementia. Paired with weight gain or loss it may signal thyroid disease. “Zoning out all of a sudden with new onset thirst and increased urinary frequency cause concern for a new metabolic disorder like diabetes,” Dr Segil adds. Regular zoning out can also occur with ADHD, Dr Dimitriu says.
See a GP if episodes are new or worsening, happen while driving, last longer than a few seconds, or come with confusion, headaches, vision changes, jerking movements, weight change, intense thirst or frequent urination. Otherwise, occasional zoning out is common—“often happening much more often than you are aware of,” says Dr Winter.
Newsletter
