Blinking gives your brain a rest

WASHINGTON — Why do we spend roughly 10 percent of our waking hours with our eyes closed — blinking far more often than is actually necessary to keep our eyeballs lubricated? Scientists have pried open the answer to this mystery, finding that the human brain uses that tiny moment of shut-eye to power down.

The mental break can last anywhere from a split second to a few seconds before attention is fully restored, researchers from Japan’s Osaka University found. During that time, scans that track the ebb and flow of blood within the brain revealed that regions associated with paying close attention momentarily go offline. And in the brief break in attention, brain regions collectively identified as the “Default Mode Network” power up.

Discovered less than a decade ago, the default mode network is the brain’s “idle” setting. In times when our attention is not required by a cognitive task such as reading or speaking, this far-flung cluster of brain regions comes alive, and our thoughts wander freely. In idle mode, however, our thoughts seldom stray far from home: We contemplate our feelings; we wonder what a friend meant by a recent comment; we consider something we did last week, or imagine what we’ll do tomorrow.

Most of us take between 15 and 20 such moments of downtime per minute, and scientists have observed that most blinking takes place near or at the point of an “implicit stop”: While reading or listening to another person, that generally comes at the end of a sentence; while watching a movie, for instance, we’re most likely to blink when an actor turns to leave the scene or when the camera shifts to follow the dialogue.

The study, published this week in the journal Proceedings of the National Academies of Science, studied 20 healthy young subjects in a brain scanner as they watched “best bits” snippets from the British comedy “Mr. Bean.” An earlier study had shown the researchers which implicit breakpoints in the “Mr. Bean” video most commonly elicited a spontaneous blink, so researchers knew when to look for changes in the brain’s activation patterns.

Sure enough, when subjects blinked, the researchers detected a momentary stand-down within the brain’s visual cortex and somatosensory cortex — both involved with processing visual stimuli — and in areas that govern attention. The circuitry of the Default Mode Network stepped up to fill the momentary lapse in attention, and then yielded again as order — and attention — was restored.

In a separate experiment, the researchers established that the momentary rest that blinking appears to represent is a deliberate act, and not just a response to an absence of stimuli. When researchers inserted roughly nine 165 milliseconds of blank screentime per minute into the “Mr. Bean” video, subjects’ Default Mode Network did not activate in response. Although the video gave them a blink’s worth of time to rest, subjects did not recognize a breakpoint in the action, and therefore remained attentive.

Though the current study didn’t examine the relationship between blinking and deception, others have: While telling a lie, liars have been found to blink less — possibly because the act of deception requires rapt and uninterrupted attention to pull it off. In the seconds after telling a lie, however, the liar will blink far more frequently than a truth-teller. Perhaps the resulting downtime is necessary for the liar to consider whether the deceived person was buying the fib — or whether it was worth telling in the first place.

Talk to us

> Give us your news tips.

> Send us a letter to the editor.

> More Herald contact information.

More in Local News

Trader Joe’s customers walk in and out of the store on Monday, Nov. 20, 2023 in Everett, Washington. (Olivia Vanni / The Herald)
New Trader Joe’s opens this week at Everett Mall

It’s a short move from a longtime location, essentially across the street, where parking was often an adventure.

Ian Bramel-Allen enters a guilty plea to second-degree murder during a plea and sentencing hearing on Wednesday, March 6, 2024, at Snohomish County Superior Court in Everett, Washington. (Ryan Berry / The Herald)
‘Deep remorse’: Man gets 17 years for friend’s fatal stabbing in Edmonds

Ian Bramel-Allen, 44, pleaded guilty Wednesday to second-degree murder for killing Bret Northcutt last year at a WinCo.

Firefighters respond to a small RV and a motorhome fire on Tuesday afternoon in Marysville. (Provided by Snohomish County Fire Distrct 22)
1 injured after RV fire, explosion near Marysville

The cause of the fire in the 11600 block of 81st Avenue NE had not been determined, fire officials said.

Ashton Dedmon appears in court during his sentencing hearing on Tuesday, March 5, 2024, at Snohomish County Superior Court in Everett, Washington. (Ryan Berry / The Herald)
Everett Navy sailor sentenced to 90 days for fatal hit and run

Ashton Dedmon crashed into Joshua Kollman and drove away. Dedmon, a petty officer on the USS Kidd, reported he had a panic attack.

A kindergarten student works on a computer at Emerson Elementary School on Wednesday, Feb. 28, 2024, in Everett, Washington. (Ryan Berry / The Herald)
‘¡Una erupción!’: Dual language programs expanding to 10 local schools

A new bill aims to support 10 new programs each year statewide. In Snohomish County, most follow a 90-10 model of Spanish and English.

Cassie Franklin, Mayor of Everett, delivers the annual state of the city address Thursday morning in the Edward D. Hansen Conference Center in Everett, Washington on March 31, 2022.  (Kevin Clark / The Herald)
At Everett mayor’s keynote speech: $35 entry, Boeing sponsorship

The city won’t make any money from the event, city spokesperson Simone Tarver said. Still, it’s part of a trend making open government advocates wary.

Logo for news use featuring the Tulalip Indian Reservation in Snohomish County, Washington. 220118
Woman drives off cliff, dies on Tulalip Reservation

The woman fell 70 to 80 feet after driving off Priest Point Drive NW on Sunday afternoon.

Everett
Boy, 4, survives fall from Everett fourth-story apartment window

The child was being treated at Seattle Children’s. The city has a limited supply of window stops for low-income residents.

People head out to the water at low tide during an unseasonably warm day on Saturday, March 16, 2024, at Lighthouse Park in Mukilteo, Washington. (Ryan Berry / The Herald)
Everett shatters record high temperature by 11 degrees

On Saturday, it hit 73 degrees, breaking the previous record of 62 set in 2007.

Snohomish County Fire District #4 and Snohomish Regional Fire & Rescue respond to a motor vehicle collision for a car and pole. The driver was pronounced dead at the scene, near Triangle Bait & Tackle in Snohomish. (Snohomish County Sheriff’s Office)
Police: Troopers tried to stop driver before deadly crash in Snohomish

The man, 31, was driving at “a high rate of speed” when he crashed into a traffic light pole and died, investigators said.

Alan Dean, who is accused of the 1993 strangulation murder of 15-year-old Bothell girl Melissa Lee, appears in court during opening statements of his trial on Monday, March 18, 2024, at Snohomish County Superior Court in Everett, Washington. (Ryan Berry / The Herald)
31 years later, trial opens in Bothell teen’s brutal killing

In April 1993, Melissa Lee’s body was found below Edgewater Creek Bridge. It would take 27 years to arrest Alan Dean in her death.

Logo for news use featuring the municipality of Snohomish in Snohomish County, Washington. 220118
Man dies after crashing into pole in Snohomish

Just before 1 a.m., the driver crashed into a traffic light pole at the intersection of 2nd Street and Maple Avenue.

Support local journalism

If you value local news, make a gift now to support the trusted journalism you get in The Daily Herald. Donations processed in this system are not tax deductible.