New research explains how sleep deprivation disrupts our brain cells’ ability to communicate with each other. The disconnect can lead to temporary mental lapses that affect memory and visual perception.
“We discovered that starving the body of sleep also robs neurons of the ability to function properly,” said senior author Dr. Itzhak Fried, professor of neurosurgery at the David Geffen School of Medicine at University of California, Los Angeles (UCLA) and Tel Aviv University.
“This paves the way for cognitive lapses in how we perceive and react to the world around us.”
Fried led an international team in studying 12 UCLA epileptic patients who had electrodes implanted in their brains in order to pinpoint the origin of their seizures prior to surgery.
As part of the procedure, patients are asked to stay awake all night to speed the onset of an epileptic episode and shorten their hospital stay.
In the current experiment, researchers asked the patients to categorize a variety of images as fast as possible while their electrodes recorded the firing of nearly 1,500 single brain cells across the group in real time.
The scientists zeroed in on the temporal lobe, which regulates visual perception and memory.
Performing the task grew more challenging as the patients grew sleepier. As the patients slowed down, their brain cells did, too.
“We were fascinated to observe how sleep deprivation dampened brain cell activity,” said lead author Dr. Yuval Nir of Tel-Aviv University.
“Unlike the usual rapid reaction, the neurons responded slowly, fired more weakly, and their transmissions dragged on longer than usual.”
In short, a lack of sleep interfered with the neurons’ ability to encode information and translate visual input into conscious thought. The same phenomenon can occur when a sleep-deprived driver notices a pedestrian stepping in front of his car.
“The very act of seeing the pedestrian slows down in the driver’s over-tired brain,” he explained. “It takes longer for his brain to register what he’s perceiving.”