Lying awake and listening for demonic footsteps after Paranormal Activity 4 may turn out to be more helpful to your mental health than trying to fall asleep. A study published earlier this month in PLOS ONE shows that losing sleep can prevent frightening memories from taking hold in the brain, at least in rats.
A good night’s sleep has many advantages, including improving our ability to recollect facts or learned motor skills. Losing sleep impairs these kinds of memory, but the impact of sleep deprivation on other kinds of memory, such as that of traumatic events, is still poorly understood.
In this study the authors Tankesh Kumar and Sushil Jha, found that when rats were trained to develop a conditioned fear response to a sound they heard, this response was twice as strong in rats that slept for six hours after the training than in those that stayed awake for this period of time. According to the authors, this result suggests that the rats that stayed awake hadn’t learned to be afraid of the sound as well as the better-rested animals had.
Despite the ill effects of sleep deprivation and associated poor memory under other circumstances, the authors suggest that losing sleep after a traumatic event can actually help prevent fearful memories from taking hold in the brain, potentially providing long-term benefits like reducing the risk of post-traumatic stress disorder (PTSD) or anxiety disorders.
Related PLOS ONE research published last year studied the effects of a similar, odor-induced fear conditioning exercise in rats, and observed changes in brain activity during sleep following the exercise. The researchers also found that these changes correlated with the strength of the fear response observed in rats the next day.
If that scary movie is still keeping you awake, read more PLOS ONE research about how dolphins can go 15 days sleeping with only half of their brain, how ostriches sleep like platypus, or the sleep behavior of the most mysterious creature of them all, the human teenager.
Citations: Kumar T, Jha SK (2012) Sleep Deprivation Impairs Consolidation of Cued Fear Memory in Rats. PLoS ONE 7(10): e47042. doi:10.1371/journal.pone.0047042
Barnes DC, Chapuis J, Chaudhury D, Wilson DA (2011) Odor Fear Conditioning Modifies Piriform Cortex Local Field Potentials Both during Conditioning and during Post-Conditioning Sleep. PLoS ONE 6(3): e18130. doi:10.1371/journal.pone.0018130
Image: another rat by asplosh on Flickr, CC-by license