Sleep deprivation may increase susceptibility to false memories, according to a recent study.

Researchers found that sleep-deprived people who viewed photographs of a crime being committed and then read false information about the photos were more likely to report remembering the false details in the photos than were those who got a full night's sleep.

Previous studies have demonstrated that failing to get your full eight hours interferes with cognitive functioning, but researcher Steve Frenda noticed a gap in the literature when it came to sleep and memory.

"Over the years I noticed that whenever I had a bad night's sleep, my perception and memory seemed to get fuzzy until I had a good recovery sleep," Frenda said. "I was surprised to find that there were so few empirical studies connecting sleep deprivation with memory distortion in an eyewitness context. The studies that do exist look mostly at sleep deprived people's ability to accurately remember lists of words-not real people, places and events."

A preliminary study conducted by Frenda and colleagues suggested that getting 5 hours of sleep or less was associated with the formation of false memories. The researchers then designed an experiment to investigate whether pulling an all-nighter would increase the likelihood of forming false memories.

For the study, researchers recruited more than 100 college-age participants and assigned them to one of four groups. Two groups were presented with a series of photos depicting a crime being committed as soon as they arrived to the lab - one group was then allowed to go to sleep, while the other group had to stay awake all night in the lab. The remaining two groups did things in the reverse order - they either slept or stayed awake all night and then viewed the crime photos in the morning.

In the second part of the experiment, the participants read narratives containing statements that contradicted what the photographs actually showed.

The researchers found that only those students who had been sleep deprived for all parts of the experiment - that is, they viewed the photos, read the narratives, and took the memory test after having stayed up all night - were more likely to report the false details from the text narrative as having been present in the crime photos.

The students who viewed the photos before staying up all night, however, were no more susceptible to false memories than the students who'd been allowed to sleep.

The researchers believe these findings have important legal applications.

"Recent studies are suggesting that people are getting fewer hours of sleep on average, and chronic sleep deprivation is on the rise," Frenda said. "Our findings have implications for the reliability of eyewitnesses who may have experienced long periods of restricted or deprived sleep."

The findings were recently published in Psychological Science, a journal of the Association for Psychological Science.