A recent psychology study tested the memories of sleep-deprived people compared to people who got a full night's sleep. The study shows that pulling an all-nighter can impair cognitive functioning to the point of forming false memories.
The researchers conducting the study showed sleep-deprived people photographs of a crime and then gave them false information about them. They then did the same to people who got enough sleep. Those in the sleep-deprived category were significantly more likely to recall false details.
Steven J. Frenda and colleagues conducted the study at the University of California, Irvine. Frenda noticed his own memory growing fuzzy after nights of bad sleep and went to the scientific literature to see if any studies addressed the problem.
"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," Frenda explained.
First, Frenda and colleagues conducted a preliminary study to test the memories of people that slept five hours or less. After finding evidence of an association with false memories, they conducted a larger experiment to test total sleep-deprivation, or all-nighters, and their association with false memory formation.
104 participants were split into four groups. The researchers showed two groups photos depicting crimes as soon as those participants walked into the lab. One of those groups then went to sleep, and the other group remained awake all night. The other two groups did everything in reverse-one group slept and the other stayed awake, and then they were all shown the photos in the morning.
Then, participants were given statements that conflicted with that they had seen in the photographs. The last part of the experiment involved a memory test in which participants reported what they remembered about the crimes. Those that remained awake all night and then saw the photos in the morning were significantly more likely to report false details about the crime, believing them to be true.
There were, however, no differences in memory between those that saw the photos upon arriving at the lab and then stayed awake all night, and those that slept.
Frenda believes these findings hold implications for legal procedures such as eyewitness accounts. The reliability of eyewitnesses in an age when chronic sleep deprivation is on the rise is something that researchers must look into, he says.
