Lack of Sleep May Trick Your Mind, Study Says
If your memory seems foggy after a night of poor sleep, it might not be all in your head.
It is believed that sleep plays a major role in the brain’s processing of memories and learning, and a recent study from the University of California, Irvine, reports that sleep deprivation causes demonstrable effects on people’s ability to accurately recall memories.
Study Shows Effects of Sleep Deprivation on Memories
Published in the Psychological Science journal July, 2014, the UC Irvine study sought to determine whether or not sleep impacted people’s ability to recall information.
Contrary to many other studies that focus on memorizing words or numbers, the this one tested participants ability to remember information from photographs of a crime scene, in order to better mimic practical connections between sleep and memory.
About The Study
The study involved 104 college-aged people split into four groups. Half of the participants were allowed to sleep normally and half were kept up all night. From both sleep condition groups, half of the participants were shown photos of a crime being committed at night, and half were shown the photos the next morning.
All participants were then tested on their ability to recall details from the crime photographs they had studied. This involved reading through narratives about the crime scene that deliberately contradicted what was in the photos and identifying what was accurate or false.
Results & Implications
One of the most interesting findings from the UC Irvine study is that people who viewed the photo and then were deprived of sleep were as accurate as those who were allowed to rest, while those who were sleep deprived and then viewed the photos were significantly more likely to report false details as accurate.
The researchers, including lead author Steven J. Frenda believes these findings have significant ramifications, especially for the legal process, due to the high percentage of people who do not get adequate rest. The article on the PsychologicalScience.org website quotes, “Recent studies are suggesting that people are getting fewer hours of sleep on average, and chronic sleep deprivation is on the rise,” says Frenda. “Our findings have implications for the reliability of eyewitnesses who may have experienced long periods of restricted or deprived sleep.”
More on Sleep & Memory
Although it is not yet known exactly how memory, learning and sleep work, it is believed that REM sleep plays a major role in storing long-term memories. Other studies have found similar detrimental effects on memorization when sleep is restricted or prevented.
For example, another 2008 study from University of Lübeck in Germany followed a similar model, but had participants learn groups of related words. The groups were either allowed to sleep or or kept awake after learning, and then either well-rested or sleep deprived when tested on the lists 9, 33, and 44 hours later.
They also found that being sleep deprived when trying to recall the information was associated with the greatest incidence of false memories. However, coffee seemed to reverse the effects, leading researchers to believe that the brain’s adenosinergic mechanisms contribute significantly to the memory impairment.
Adenosine is a chemical that builds up in the brain during wakefulness, and is cleared out during sleep. Caffeine in coffee blocks adenosine receptors, temporary relieving drowsiness associated with adenosine.
A Singapore university study from 2009 also found sleep reduced false memories in older adults, and another study published 2009 in the Learning & Memory journal similarly found that sleep reduced incidence of false memories and increased accuracy, showing that both sleep after learning and before recall are likely both important.
These studies seem to indicate it’s best to learn in a non-sleep deprived state, but that it is even more important to be well-rested when you’re trying to remember information. While not getting rest doesn’t erase memories, it does appear to reduce accuracy and affect recall later on.
For students, this supports the idea that it is bad to cram all night and try to take exams tired the next day, as the brain may struggle to recall the learned data. Other research focusing on learning, testing and sleep in students have found similar results.
For adults, these studies show that sleep proves important to memory, so for jobs and tasks that require accuracy, getting rest is important. As study authors point out, this even holds implications for juries and other functions that rely on people to accurately recall information.
The UC Irvine study’s indication that the biggest impact may be on things we experience when already in a sleep-deprived state will prove interesting for future research. Though all the mechanisms behind rest and learning aren’t completely understood, it seems fairly likely that you can improve your memory (and your overall health) by getting adequate rest and following healthy sleep hygiene practices.
Share: What do you feel like are the biggest side effects of sleep deprivation, or how have you noticed that tiredness affects your memory?
There are no comments yet, add one below.