Study: Skipping sleep may increase risk of false memories, compromise criminal investigations

Skipping a few hours of sleep here and there, or even on a regular basis, may seem like a small price to pay to fit in some extra socializing or get that last bit of work done. But the Centers for Disease Control and Prevention have called insufficient sleep a public health epidemic. And new research suggests there’s yet another reason sleep needs to be taken seriously.

A study published online last month in the journal Psychological Science found sleep deprivation may increase the risk of false memories or memory distortion.

The researchers -- from the University of California, Irvine, and Michigan State University -- used two methods meant to reflect real-world situations. In one, a questionnaire reminds study participants of a big news event more than 10 years in the past -- in this case the passenger jet that crashed on Sept. 11, 2001, in Shanksville, Penn. The description suggested that video footage had been broadcast widely, when in fact the incident had been captured in photos but not video.

Those who had slept an average of less than five hours per night in the preceding week were significantly more likely to indicate they’d seen the phantom footage than those who were “rested”  --  54 percent compared to 33 percent.

In another experiment, participants saw two series of photographs depicting unfolding events, of a man breaking into a car and a woman getting her wallet stolen. Then they read a text version of the scenario that included three incorrect points and answered questions — about the content as well as where they remembered the information from — to see whether the inconsistencies had seeped into their memories of the photo sets.

“The three phases are actually similar to how memory changes in real life,” -- encoding, misinformation and test or retrieval, said Kimberly Fenn, associate professor at Michigan State University. When the experiment was run the morning after one group of participants had slept eight hours in the lab and another group had been kept awake all night  ”the false memory rate was significantly higher in the sleep-deprived group than in the rested group.”

False memories can have serious consequences in the context of the criminal justice system. “The paradigm is meant to mimic when someone actually witnesses a crime or accident or legally relevant event and then is subsequently exposed to other information by bystanders, interrogation, or media coverage” said Elizabeth Loftus, a professor in the Criminology, Law and Society and Psychology and Social Behavior departments at UC, Irvine.

Eyewitness misidentification is the most common theme in wrongful convictions later overturned by other investigation, including DNA, according to the Innocence Project, a nonprofit legal clinic.

Loftus said this is the first major study on sleep deprivation and memory distortion whose methods resemble realistic memory formation  and future studies will look more closely at false autobiographical memories — things people remember about themselves — and the impact on false confessions, another paradigm that could have particular significance for the criminal justice system.

YOUR SLEEP
The study also outlines other negative consequences of sleep deprivation including impairing performance of a wide range of cognitive tasks, slowing reaction time and decreasing the potential for memory and learning new things.

Dr. Frank Coletta, co-director of the Center for Sleep Medicine at South Nassau Communities Hospital, said typical adults need six to eight hours of sleep to function at their prime.

Coletta gives a few tips for maintaining healthy sleep habits:
-- Establish a quiet sleep environment.
-- The bed should be reserved for sleep and sex. If you want to read, watch television, or do anything else, sit in a chair or go to another room.
-- “Do some ritualistic behaviors before going to bed,” Coletta said, such as taking a warm shower to relax.
-- Try not to eat anything in the hour or two before going to bed, especially anything caffeinated. If you must have a snack, he says, stick with something that contains tryptophan, like a banana or milk.
-- Invest in a good mattress and good pillows.
-- “One of my favorites with patients who can’t get rid of thoughts about work, concerns related to stressors for the next day,” Coletta said. “Keep a pen and a pad by the bedside and when some of those intrusive thoughts start to interfere with getting to sleep, I tell them to write them down on the pad and that’s sort of cathartic for them. And studies have shown that that helps with sleep introduction.”

Dr. Avram Gold, medical director of the Stony Brook University Sleep Disorders Center, warned that some common ailments could actually be related to sleep deprivation, among them: Insomnia, daytime sleepiness, chronic fatigue, headaches, muscle or joint pain, irritable bowel, and PMS. In that case, you should consider seeing a sleep specialist, he said.

“It’s very important that you be evaluated at a sleep disorders center that recognizes and treats mild sleep disordered breathing,” he said.