What’s Going On Inside Your Brain When Your Mind Goes Blank?

There’s a lot that goes on inside our brains. But there are times that our minds go… well… what’s the word? Blank?

Reviewing available research on mind blanking, a new article in Trends in Cognitive Sciences says that the moments in which we are “thinking about nothing” are actually a lot more complex than we might think, as they tend to correspond with physiological, neural, and cognitive changes in our brains and bodies.

Taken as a whole, the new article suggests that the blanking mind represents a distinct and phenomenally diverse mental state — a state that scientists are only starting to understand.

When we’re awake, our minds move from one mental state to another, with the majority of these mental states being characterized by “contents.” These contents are the topics that are on our minds — the things and ideas that our mental states are “about.” Though our minds typically transition seamlessly from one mental state to another, and thus from one content to another, there are some instances in which our minds happen to arrive at a mental state without any recognizable or reportable content at all.

That’s the definition of mind blanking, which is also sometimes defined as an absence of thoughts or an absence of awareness. Indeed, though we’ve all experienced these blips in our own thinking, mind blanking is surprisingly difficult to define, with some scientists even describing it as a form of drowsiness.

As difficult as mind blanking is to define, it’s also difficult to study. Setting out to review what researchers have revealed about mind blanking so far, the authors of the new Trends in Cognitive Sciences article examined the changes in our physiology, neurology, and cognition that occur as our minds blank out.

“We sought to better understand mind blanking by parsing through 80 relevant research articles — including some of our own in which we recorded participants’ brain activity when they were reporting that they were ‘thinking of nothing,’” said Athena Demertzi, an author of the article and a neuroscientist at the University of Liège, Belgium, according to a press release.

Read More: The Science Of A Wandering Mind

Revealing the frequency of the occurrence, the authors found that mind blanking occurs with around 5 to 20 percent frequency in the available research. They also found that mind blanking typically takes place toward the end of sustained attention tasks or after, and also after periods of sleep deprivation and physical activity.

Not only that, the team also suggested that sustained-attention-task mind blanking is associated with physiological and neural changes in people’s heart rate, pupil size, and brain activity. Tied to the latter are declines in the speed and the complexity of brain waves that are a lot like the declines seen in sleeping or unconscious brains.

The researchers added that different types of mind blanking were associated with different types of brain activity, with mind blanking during sustained attention tasks appearing differently in the brain than mind blanking during rest. And, in addition to the physiological and neural changes, the researchers found a variety of cognitive changes associated with mind blanking, too, including slips in attention, memory, and inner speech.

Read More: Scientists Aren't Sure How the Inner Voice Works

Previous research has regarded mind blanking alongside mind wandering. But while similar, mind wandering and mind blanking are two distinct experiences. Mind wandering occurs when the mind moves from an external task to an internal task or thought, whereas mind blanking occurs when the mind goes “nowhere” instead of “elsewhere.”

According to the authors of the new Trends in Cognitive Sciences article, mind blanking is its own experience, which leaves people slower, sleepier, and more mistake-prone than mind wandering does. And not only is it a distinct experience; it is also a diverse experience, since its physiological, neural, and cognitive impacts vary so much. As Jennifer Windt, another author and a philosopher at Monash University in Australia, said, according to the release, “The experience of a ‘blank mind’ is as intimate and direct as that of bearing thoughts.”

The article suggests that arousal levels shape the various types and impacts of mind blanking. But regardless of its specific findings, the article contributes to our current understanding of mind blanking and could contribute to our future understanding of mind blanking, too.

"We believe that the investigation of mind blanking is insightful, important, and timely,” said Thomas Andrillon, the lead author of the article and a neuroscientist at the Paris Brain Institute, according to the release. “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.”

Read More: Do You Have an Inner Voice? Science Can’t Agree If Everyone Does

Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:

• Trends in Cognitive Sciences. Where Is My Mind? A Neurocognitive Investigation of Mind Blanking

Sam Walters is a journalist covering archaeology, paleontology, ecology, and evolution for Discover, along with an assortment of other topics. Before joining the Discover team as an assistant editor in 2022, Sam studied journalism at Northwestern University in Evanston, Illinois.