Research lead and study author Daniel Buysse explained, “While patients with insomnia often have their symptoms trivialized by friends, families, and even physicians, the findings in this study add strong evidence to the emerging view that insomnia is a condition with neurobiological as well as psychological causes.”
The researchers found that brain activity during sleep is more nuanced than previously believed, with different brain regions experiencing varying “depths” of sleep.
The findings may help improve treatment methods for insomnia and offer a greater understanding why some treatments work better than others. For example, mindfulness meditation works better for some patients, but not for others.
The researchers used positron emission tomography (PET) scans where participants were injected with a solution of glucose molecules. Brain regions with higher activity took up higher levels of the glucose solution and were more metabolically active on the scans.
The information collected from the PET scans revealed relative activity differences in specific brain regions during periods of sleep and wakefulness. These differences may be attributed to either decreased activity during wakefulness or heightened activity during sleep.
The results indicate that sleep is not uniform among the different brain regions, going against the previous notion that the brain is “on” while awake and “off” while asleep.