研究發現失眠者大腦可塑性更高

最新研究顯示，比起睡眠良好的人，失眠人群大腦的可塑性可能更強。

研究人員徵集了28名成年受試者，用經顱磁刺激(TMS)激活受試者腦中的運動皮質區域，這28人中，18人患有失眠症，10人沒有失眠症。受試者收到刺激後四肢會向特定方向不自主運動。

研究人員在受試者四肢上綁定加速計測量運動幅度，接下來觀察受試者在四肢不受控運動下，多久能學會往反方向控制四肢運動。研究人員說，在這種條件下，適應的越快，運動皮質的靈活度就越好。

研究人員開始還擔心失眠患者的大腦會因休息不良難以控制四肢，但是試驗結果卻讓人大跌眼鏡。結果顯示慢性失眠症患者適應地更快，因為他們的大腦有更強的可塑性。

失眠症狀如何導致可塑性提高的聯繫還不能確定，科學家也不知道具體作用機制，也不清楚可塑性提高是否是失眠導致。

 

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.

（來源：guardianlv.com 編輯：丹妮）