研究发现失眠者大脑可塑性更高

最新研究显示，比起睡眠良好的人，失眠人群大脑的可塑性可能更强。

研究人员征集了28名成年受试者，用经颅磁刺激(TMS)激活受试者脑中的运动皮质区域，这28人中，18人患有失眠症，10人没有失眠症。受试者收到刺激后四肢会向特定方向不自主运动。

研究人员在受试者四肢上绑定加速计测量运动幅度，接下来观察受试者在四肢不受控运动下，多久能学会往反方向控制四肢运动。研究人员说，在这种条件下，适应的越快，运动皮质的灵活度就越好。

研究人员开始还担心失眠患者的大脑会因休息不良难以控制四肢，但是试验结果却让人大跌眼镜。结果显示慢性失眠症患者适应地更快，因为他们的大脑有更强的可塑性。

失眠症状如何导致可塑性提高的联系还不能确定，科学家也不知道具体作用机制，也不清楚可塑性提高是否是失眠导致。

Unable to sleep at night? It has now been medically shown that insomnia may be caused by an overactive brain, according to a new sleep study conducted by Dr. Rachel Salas, assistant professor of neurology at Johns Hopkins University School of Medicine and head author of the new research project.

Salas stated in the report from their research in Sleep Journal that insomniacs have more active brains than sound sleepers, and the disorder is not something that occurs only at night. Insomnia is “more of a 24/7 disorder,” she said. “The light switch is continually on.”

Originally, Salas assumed that deep sleepers had more plastic and attentive brains. She explained that brain plasticity is how easily neural pathways can be tailored by experience and adapt to change. Salas set up a sleep study including 28 participants: 18 who suffered from chronic insomnia for more than a year and 10 people with no trouble sleeping.

Each subject was given 65 electrical pulses to the brain using transcranial magnetic stimulation (TMS), targeting a specific point in the motor cortex. The researchers focused on stimulating involuntary movements of each person’s thumb and then asked volunteers to move their thumbs for 30 minutes in the opposite direction (without electromagnetic currents) as the uncontrolled reaction caused by the experiment.

The volunteers were then pulsed a second time to see if their brains had learned to move their thumbs in the new direction. If the thumbs twitched in the new path, it showed that the brain was adaptable to change.

Salas assumed that because lack of sleep has been associated with decreased memory and concentration during the day, the brains of the sound sleepers would be more easily trained. Ironically, the opposite was true. The results showed that plasticity was more prevalent in the brains of individuals with insomnia. Salas’ report also found a link between increased plasticity and amplified excitability. So basically, insomniacs have more ongoing brain activity than deep sleepers.

More research still needs to be done in order to learn more about why insomniacs have a more active brain and are able to acclimate easier to modifying the thinking process. Salas stated that the increased metabolism, cortisol levels, and constant worrying symptoms that occur in individuals with insomnia may be linked to plasticity in some way. Unfortunately, there is not one single treatment that works for all people with sleep deprivation issues.

Many people have tried numerous different types of methods including therapy, sleeping pills, and Eastern medicine, but none of these have produced conclusive results that is a definite solution to the problem. Insomniacs have even turned to “sleep whisperer” Ilse Blansert’s controversial phenomenon known as Autonomous Sensory Meridian Response (ASMR) for help.

Salas said she hopes to conduct a more in depth sleep study to find treatments for the hyperactive brain to alleviate those who suffer from insomnia. Although there is not currently a “cure” for insomnia, Salas believes that TMS could prove to reduce excitability for people with the disorder.