Struggling to focus? Maybe you are brainwashed
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We all know it can be difficult to focus when you’re sleep deprived, but why does this happen? This may be because your brain is trying to refresh itself, causing temporary lapses in attention.
During sleep, the brain performs a rinsing cycle, in which cerebrospinal fluid (CSF) repeatedly flows into the organ and then exits again at the base of the brain. This process gets rid of metabolic waste that has accumulated during the day, which would damage brain cells.
Laura Lewis She and her colleagues at MIT wondered whether attention lapses, which typically occur after sleep deprivation, might result from the brain trying to catch up on itself when it’s awake.
To explore this idea, the researchers asked 26 people between the ages of 19 and 40 to get a good night’s sleep that left them feeling well rested, then kept them awake all night in the lab two weeks later.
In both cases, the team recorded the participants’ brain activity using MRI scans the next morning, while they completed two tasks. During these tests, participants had to press a button whenever they heard a certain tone or saw a cross on the screen that turned into a square. This happened dozens of times within 12 minutes.
As expected, participants failed to press the button more often when they were sleep-deprived than when they were rested, meaning that lack of sleep made it more difficult to concentrate.
More importantly, when the researchers analyzed the brain scans, they found that the participants lost focus for about two seconds before the cerebrospinal fluid was expelled from the base of the brain. Furthermore, cerebrospinal fluid was drawn back into the brain about 1 second after attention was restored.
“If you think of brain cleaning like a washing machine, you need to put water in and stir it and drain it, so we’re talking about the flow part that happens during these attention lapses,” Lewis says.
The findings suggest that when the brain can’t clean itself during sleep, it does when you’re awake, but this impairs concentration, Lewis says. “If you don’t have these waves [of fluid flowing] At night because you stay up all night, and then your mind starts creeping into it during the day, but it comes with this cost of attention.
Exactly why this cleaning process leads to a loss of attention remains unclear, but identifying the brain circuits responsible could reveal ways to reduce the cognitive effects of sleep deprivation, Lewis says.
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