On any given day, your thoughts leap from one subject to another — your grocery list, a deadline, a song stuck in your head. But sometimes, they stop altogether. You stare at the screen. The page. The road ahead. Nothing comes to mind.

You’re not distracted. You’re simply… not thinking of anything — and that’s fine.

These mental pauses are known as mind blanking (MB). They’ve been casually acknowledged in everyday life and even laughed off as forgetfulness. But a new paper by neuroscientist Thomas Andrillon and colleagues suggests they may represent a distinct and reportable state of consciousness. And, if we take them seriously, they might upend what we think we know about the mind’s continuous stream.

“During wakefulness, our thoughts transition between different contents. However, there are moments that are seemingly devoid of reportable content, referred to as mind blanking,” the researchers wrote in an opinion article published April 24 in Trends in Cognitive Sciences.

The team of neuroscientists and philosophers compiled and reviewed everything that science has found thus far about mind blanking, including their own brain-imaging studies. They now offer a new framework: that mind blanking is not a failure of thought, but a distinct and measurable mental state shaped by physiology.

The Blank Spot in the Stream of Consciousness

The mind’s inner life is sometimes described as a flowing river of thoughts. From memories and plans to inner monologues and fleeting images, this stream was assumed to always carry something. But sometimes this river runs dry.

Until now, scientists studied mind blanking as a subset of mind wandering — those drifting thoughts we notice when we lose track of a conversation or get lost in daydreams. But the authors argue that blanking should be treated separately. When we wander, our thoughts drift away from a task, but they’re still there—we might think about dinner or yesterday’s conversation. In MB, there’s no content at all.

And compared to mind wandering, people who blank report feeling sleepier, more sluggish, and are more prone to making errors. And while the experience varies from person to person, it’s surprisingly common. The authors estimate that we spend between 5% and 20% of our waking time in this state, whether we realize it or not.

Common signs include attention lapses, forgotten information, and the sudden disappearance of inner speech — all of which become more likely during monotonous tasks, after a bad night’s sleep, or even after intense exercise.

People report them spontaneously or after being asked what was on their mind just moments earlier. Often, their answer is simple: nothing.

Not Wandering. Not Sleeping. Just Blank.

The new study outlines several types of MB. Some people enter the state deliberately; think of meditators instructed to “think of nothing.” Others find themselves there by accident. Some realize it as it happens; others only recognize it in hindsight. There may even be blanks we never notice at all.

Mind blanks tend to show up more often when we’re tired, sleepy, or even after intense physical exertion. Researchers have linked these moments to sluggish behavior, slower reaction times, and physiological signs like lower heart rate and pupil constriction.

“Our aim here is to start a conversation and see how mind blanking relates to other seemingly similar experiences, such as meditation,” added Antoine Lutz of the Lyon Neuroscience Research Center in France.

To probe MB, the scientists used tools like EEG and fMRI. They observed increased slow-wave brain activity, similar to what happens at sleep onset, even though participants were awake and responsive. They call this “local sleep,” a phenomenon where parts of the brain briefly power down while the rest stays alert.

The Moments Before the blank

Heart rates slow. Pupils constrict. The world blurs. And during moments when participants were instructed to actively empty their minds — a kind of induced blanking — scientists observed deactivations in areas tied to speech, memory, and motor planning, including Broca’s area and the hippocampus.

They also noted globally positive brain connectivity, where all regions of the brain talk to each other equally, suggesting a loss of the usual specialization that defines active thought. Such uniform communication between brain regions may be mediated by low vigilance, the researchers say.

But other cases were quite the opposite. In some people, a sudden spike in neural activity in the brain’s posterior regions preceded a blank. The authors believe that high-speed thinking might overwhelm key cognitive systems, producing a kind of mental overload.

They suspect one common factor unites these otherwise divergent episodes: changes in arousal, the brain’s measure of physiological readiness. Too high, and you burn out. Too low, and you drift. In either case, the mind needs to go quiet.

“The experience of a ‘blank mind’ is as intimate and direct as that of bearing thoughts,” said Jennifer Windt of Monash University in Australia.

The Philosophy of Nothing

Is MB a form of consciousness, or rather its absence? Can a state with no content still be an experience?

In many meditative traditions, the answer is yes. Practitioners speak of “pure awareness,” a state devoid of thought, yet deeply present. The researchers compare MB to these meditative states, suggesting both involve “a minimal phenomenal experience” without specific content.

They stop short of saying they’re the same. Meditation is often deliberate and accompanied by heightened meta-awareness. MB is more elusive, slipping in when we least expect it.

Still, the parallel is compelling. “By contrasting these different dimensions,” they argue, “we can identify key features that separate MB and allegedly contentless states from content-oriented experiences.”

A Common Experience, Sometimes with Clinical Implications

Mind blanking features in the DSM-5 as part of generalized anxiety disorder and appears in other neurological conditions, from ADHD to seizures to Kleine–Levin syndrome, in which patients sleep for up to 20 hours at a time.

Understanding MB, then, could shed light on how the brain malfunctions in these conditions. It might also offer new ways to evaluate consciousness in non-responsive patients, or guide therapies that involve mindfulness and cognitive training.

“We believe that the investigation of mind blanking is insightful, important, and timely,” says lead author Thomas Andrillon of the University of Liège. “Insightful because it challenges the common conception that wakefulness involves a constant stream of thoughts. Important because mind blanking highlights the interindividual differences in subjective experience. Collectively, we stress that ongoing experiences come in shades with varying degrees of awareness and richness of content.” 

As William James once wrote, “The stream of thought is like a river.” Sometimes, perhaps, the most revealing thing is not the current, but the stillness between the waves.