Sleep Deprivation May Impair Memory
Staying Up All Night Makes for Fuzzy Memories, Study Shows
Feb. 12, 2007 -- Want a sharper memory? Get some sleep.
Sleep deprivation tends to hamper the brain's ability to make new memories,
a new study shows.
The study, published online in Nature Neuroscience, comes from
researchers at Harvard Medical School and Boston's Beth Israel Deaconess
In the study, Matthew Walker, PhD, and colleagues studied 28 healthy young
adults aged 18-30 (average age: 22).
Walker's team split participants into two groups for the four-day study.
Starting on the first day, the researchers kept one group awake for 35
straight hours at the Beth Israel Deaconess Medical Center.
Those participants were allowed to use the Internet or email, take short
walks, read, or play board games. But they weren't allowed to sleep -- not even
a quick nap.
Meanwhile, participants in the other group spent a normal night at home with
no sleep restrictions.
Sleepy Brain Scans
At 6 p.m. the next day, all participants watched a slide show. They saw 150
slides of landscapes, objects, and people who weren't celebrities.
Meanwhile, participants got high-tech brain scans, using functional magnetic
resonance imaging (fMRI).
Those brain scans showed that certain areas of the brain involved in memory
were more active in participants who hadn't been deprived of sleep.
After the slide show, everyone went home to sleep, with no sleep
restrictions. But the study wasn't over just yet.
The following evening, participants took a pop quiz on the slides they had
seen 24 hours earlier.
They saw the same 150 slides, randomly mixed with 75 new slides.
Each slide was shown on a computer screen for a fraction of a second.
Immediately after each image faded, participants had to indicate whether they'd
seen it before.
Those who had been sleep deprived on the first night of the study performed
worst -- even though they'd had a night to catch up on their sleep.
Those results could be particularly important nowadays, as many people skimp
Walker's team calls the findings "worrying ... considering society's
increasing erosion of sleep time."