The science of blanking out

We’ve all had those moments. You’re reading a page, only to realize you haven’t absorbed a single word. Or you pause mid-sentence, unable to recall what you were about to say. Sometimes, it feels as though the entire theater of the mind has gone dark, the stage empty, the lights off, the script missing. Psychologists and neuroscientists have a name for this mysterious state: mind blanking.

A team of researchers, Thomas Andrillon (Paris Brain Institute), Antoine Lutz and Jennifer Windt (Monash University), and Athena Demertzi (University of Liège), have just published a sweeping investigation into this puzzling phenomenon in Trends in Cognitive Sciences. Their paper, “Where is my mind? A neurocognitive investigation of mind blanking”, takes us on a tour of what happens when we report thinking of… nothing at all.

A quiet corner in the stream of consciousness

Psychologists have long described our inner life as a stream of thought, a ceaseless flow of images, words, sensations, and memories. For decades, researchers focused on mind wandering, those familiar moments when attention drifts away from the here and now, toward daydreams or unrelated concerns. But mind blanking is different. Where mind wandering takes us elsewhere, mind blanking seems to take us nowhere. People report a genuine absence of mental content: “I wasn’t thinking of anything.”

This raises profound questions: Is it possible to be conscious without any thoughts or images? Or does blanking reflect a lapse of attention, memory, or awareness altogether? The authors argue that, rather than being mere glitches, mind blanks deserve recognition as a distinct mental state, one with its own psychological and neural signatures.

But..how do scientists measure nothingness?

Studying “nothing” isn’t easy. Researchers rely on creative methods to catch blank moments in the act. In lab experiments, participants may be asked to press a button whenever they notice their mind has gone blank (“self-caught”), or they may be interrupted at random and asked what was happening in their head (“probe-caught”).

Across studies, people report mind blanking about 5–20% of the time, roughly a third as often as mind wandering. That’s surprisingly frequent. Some individuals hardly ever report blanks, while others, especially children or adults with ADHD, report them far more often. The challenge, however, is that different studies define “blanking out” in very different ways. Some ask about an “empty mind,” others about lapses of awareness, drowsiness, or memory failures. The new paper highlights this conceptual messiness and calls for a unified framework.

Neuroscience tools like EEG and fMRI are beginning to sketch the brain’s behavior during blanks. The results suggest that the brain isn’t simply “off” but operating in a distinctive mode. For instance, EEG shows reduced complexity in electrical activity during blanks (basically, slowed signals), patterns more reminiscent of sleepiness than of active thought. Also, researchers find slow-wave brain activity during blanks, echoing what happens at the onset of sleep. This has led to the idea that mind blanking may represent a kind of “local sleep” happening in an otherwise awake brain. Moreover, fMRI studies reveal that, during blanks, communication among brain regions becomes more uniform and globally synchronized, again suggesting low vigilance rather than active, content-rich thought.

Together, these findings hint that blanking may occur when the brain slips into a halfway state between wakefulness and sleep, alert enough to respond if needed, but too drowsy to sustain rich mental content.

Blank minds, meditation, and “white dreams”

The authors also compare mind blanking with other states in which content seems reduced or absent. For example, many contemplative traditions describe meditations as “empty mind” states, moments of stillness where thoughts dissolve, leaving only awareness itself. Unlike spontaneous blanking, however, meditative emptiness is often deliberate, cultivated with effort and intention. Sometimes people report “white dreams”, a sense of having been aware during sleep, but unable to recall any details. Are these forgotten dreams, or genuine contentless experiences? The debate is ongoing, but they resemble waking blanks in intriguing ways. These comparisons suggest that blanking isn’t unique to day-to-day wakefulness but may belong to a broader family of “contentless” states spanning meditation, sleep, and pathology.

Mind blanking is not only a curiosity of everyday life, it also appears in clinical contexts. In fact, people with generalized anxiety disorder often report their “mind going blank” under stress. Children with absence seizures display brief blank stares and report gaps in awareness afterward. Patients with rare neurological conditions, like autoactivation deficit syndrome or Kleine–Levin syndrome, sometimes describe prolonged stretches of emptiness. These links hint that studying blanking could shed light on disorders where awareness, attention, or self-generated thought are disrupted.

The authors don’t claim to have solved the riddle of what it means to have no thoughts. But they propose a “physiocognitive account”, a layered explanation that considers physiology, neural architecture, and cognitive processes together. Arousal provides the foundation. Too low (drowsy) or too high (overstimulated) arousal can destabilize thought. Neural connectivity then determines whether information can propagate across brain regions. Failures here may prevent thoughts from taking shape. Cognitive mechanisms, like memory, language, and attention, may falter, leaving us unable to retrieve or verbalize content. Depending on which of these processes breaks down, blanking may feel different: a sleepy lapse, a deliberate emptying, or a sudden disappearance of thought.

Consequently, the authors leave us with big, open questions. Are all blanks the same, or is there a spectrum of blank states? Can people learn to cultivate blankness, as meditators do? Do some blanks go entirely unnoticed? And how should consciousness theories adapt to include these curious “absences”?

And wait, I had one more question, but my mind is blanking right now.

If you want to learn more, read the original article titled "Where is my mind? A neurocognitive investigation of mind blanking" on Trends in Cognitive Sciences at http://dx.doi.org/10.1016/j.tics.2025.02.002.