Getting a decent amount of sleep is vital for a variety of reasons. It allows your body to rest, curate memories and heal, while also allowing you to feel great the next day. Lack of adequate sleep also poses serious risks. A recent study suggests that cutting down your sleep time by half reduces the brain’s ability to unlearn unpleasant memories.
Military and medical personnel tend to work for long hours and often sleep for very few hours. The inability to unlearn negative or unpleasant memories puts them at risk of mental conditions such as post-traumatic stress disorder or anxiety. The study findings are available in the Cognitive Neuroscience and Neuroimaging Journal.
Dr. Cameron Carter, the journal’s editor, stated that the study allows scientists to understand the effects of sleep deprivation on the brain and how it prevents the mind from eliminating fear. The research was a collaborative effort between Massachusetts General Hospital, Harvard Medical School, and University of Pittsburgh researchers. The study featured 150 human subjects observed through a sleep laboratory.
A third of the study subjects were allowed normal sleep, while a third slept for half of the night. The third group did not get any sleep, and all subjects went through fear conditioning. Dr. Pace-Schott, one of the researchers, pointed out that the research featured MRI scanning through a three-phase model. The fear conditioning study segment featured three colors, but every time the subjects saw two of the colors, they received an electric shock.
Once the fear phase was complete, the subjects were then shown one of the colors, and no shock would be administered. The objective was to facilitate fear extinction so that the subjects could unlearn the fear associated with electric shocks while also learning that it was now safe to see the colors without any shock administered. The researchers conducted another fear test to determine whether the subjects unlearned the fear by showing them the three colors again.
The MRIs recorded during the fear period indicate activation of brain areas responsible for emotional regulation. For example, the prefrontal cortex in subjects that experienced normal sleep showed a difference in activity than patients in the disrupted sleep category. Individuals who did not sleep did not show any activation in brain areas responsible for fear during fear conditioning and fear extinction. Individuals who got half a night’s sleep worth demonstrated the highest brain activation in areas responsible for fear.