Sleep is extremely important. Most of us know that on some level, yet many of us still do not get enough sleep. There have been countless studies examining the psychological effects of sleep deprivation, including one that examined its effect on the formation of false memories (Lo et al., 2016). This article will briefly review the findings of that paper, which consisted of two experiments.
Experiment 1 Methods
The first experiment examined 58 healthy undergraduate students who did not have sleep apnea and did not consume excessive amounts of caffeine. These participants were randomized into a control group, a partial sleep deprivation (PSD) group, and a total sleep deprivation (TSD) group.
- The control group was instructed to stay in bed for eight hours each night for a week
- The PSD group was instructed to stay in bed for five hours each night for a week
- The TSD group was instructed to sleep normally for a week, then stay awake for 25 hours for experimentation
On the day of experimentation, all three groups participated in a “misinformation paradigm” which consisted of the following:
- An event-encoding phase (two sets of 50 photographs of a crime were presented)
- A misinformation phase (narratives were paired with the prior photographs, with many of the narratives contradicting the photograph)
- Memory and source tests (testing the participants on their memory of the original photographs)
In addition, the following two measures were used:
- A Psychomotor Vigilance Task (PVT) to “measure sustained attention between successive phases of the misinformation paradigm”
- The Karolinska Sleepiness Scale (KSS) to “measure levels of subjective sleepiness”
Experiment 1 Results
The following results were obtained:
- The PSD and TSD groups showed more attention lapses (according to the PVT) than the control group
- PSD and TSD increased subjective sleepiness levels according to KSS
- The TSD group showed a significantly higher rate of responses consistent with misinformation than the control group
Experiment 2 Methods
This experiment examined 54 secondary school students that were not “short sleepers” and who did not consume excessive amounts of caffeine. These participants were randomized into a control group and a PSD group. A week prior to the study period, all participants were instructed to sleep for nine hours a night. During the study period, the control group continued being allowed to sleep for nine hours a night. Meanwhile, the PSD group was allowed to sleep for nine hours a night for three nights, then limited to five hours a night for seven nights, then back to nine hours a night for three nights as a recovery period. The participants then underwent the same misinformation paradigm used in experiment 1, and the PVT and KSS were also used again.
Experiment 2 Results
The following results were obtained:
- The PSD group showed more attention lapses (according to the PVT) than the control group
- The PSD group reported being sleepier (according to KSS) than the control group
- The PSD group showed a significantly higher rate of responses consistent with misinformation than the control group
Wrapping up
Altogether, the results of both experiments suggest that partial or total sleep deprivation can increase the formation of false memories based on the rate of responses consistent with misinformation. These increased rates of false memories were also associated with increased sleepiness and increased attention lapses. Interestingly, these results were found with both total sleep deprivation (no sleep at all the night before experimentation) and partial sleep deprivation (a few nights of short sleep days before experimentation). In other words, not getting any sleep at all can lead to the formation of false memories, but so can consistently getting not enough sleep. In other words, to perform the best on memory and attention tasks, it is crucial to consistently get enough sleep.
References
Lo, J.C., Chong, P.L.H., Ganesan, S., Leong, R.L.F., Chee, M.W.L. (2016). Sleep Deprivation Increases Formation of False Memory. Journal of Sleep Research, 25(6), 673-682. doi: 10.1111/jsr.12436.
