Oct. 6 (UPI) -- New research suggests that staring into space while a person is awake is a natural phenomenon -- even if it is at times annoying.
The brain imaging study by European researchers challenges the notion that the human mind is constantly thinking, and suggests that "mind blanking" is a distinct mental state in which the brain essentially goes offline: a mode similar to deep sleep, only while awake.
The findings, indicating the brain cannot sustain a constant stream of thought, appeared this week in the journal Proceedings of the National Academy of Sciences.
"Mind blanking is a relatively new mental state within the study of spontaneous cognition. It opens exciting avenues about the underlying biological mechanisms that happen during waking life," Dr. Athena Demertzi, the study's principal investigator, said in a news release.
"It might be that the boundaries of sleep and wakefulness might not be that discrete as they appear to be, after all," she said.
Demertzi, a researcher at GIGA CRC In vivo Imaging at the University of Liège (Belgium), conducted the study with scientists from EPF (École Polytechnique Fédérale) Lausanne, a public research university, and the University of Geneva, both in Switzerland.
According to the research team, continuously and rapidly changing brain activity requires robust analysis methods to confirm specific characteristics of mind blanking.
They reanalyzed a previously collected set of data in which a few dozen healthy participants were asked to indicate their mental state, given a few options, before hearing a beep as they rested in an MRI scanner and brain images were taken.
The researchers found that episodes of mental absence were reported infrequently, compared to the other mental states, and infrequently recurred over time.
Using artificial intelligence, the scientists found that during mind-suppressing, or mind blanking, episodes, all regions of the brain are communicating with each other at the same time, the release said.
And this ultra-connected brain pattern was further characterized by "a high global fMRI signal amplitude," an indicator of "a low level of cortical arousal" -- similar to deep sleep mode.
Researchers said this could explain a person's inability to report mental content due to the brain's inability to differentiate signals -- suggesting that what they called "instantaneous unreportable mental events" may occur during wakefulness.
They said their study paves the way for further exploration of what mechanisms underlie the mind blanking phenomenon.