The research involved college students who studied lists of words; 12 hours later they were tested. From a list with new words mixed in, they had to identify words that they had studied 12 hours earlier.
Some students studied the original word list at 10 a.m.; they were tested at 10 p.m. after spending the day awake. Other students studied the words at night; they were tested in the morning after at least six hours of sleep.
Results show that false recognition of non-studied words was reduced after sleep; there was no change in correct recognition of studied words.
“It’s easy to muddle things in your mind,” Fenn said in a Michigan State University news release. “This research suggests that after sleep you’re better able to tease apart the incorrect aspect of that memory.”
How does this process work? Fenn suggested that sleep may strengthen the source of a memory. Or a long period of wakefulness may hinder your ability to remember; your memories may be confused with other information that you gathered while awake.
In a video statement Fenn added that the findings could be important for students. After a full night of sleep you might be more likely to pick out the wrong answers on a multiple-choice test.
Sleep also could help you take medications safely; you might be less likely to confuse medications or have a false memory of taking them.
A recent article in the New Zealand Herald examined the impact of false memories on the legal system. It reports that eyewitness error is a factor in 75 percent of wrongful convictions in the U.S.
The article suggests that false memories are easily created. These false memories can be powerful; people with false memories tend to have absolute confidence that they are right.
Learn more about sleep and memory.