科學(xué)家可以看到我們睡覺時大腦是如何記錄我們的記憶的

科學(xué)家可以看到我們睡覺時大腦是如何記錄我們的記憶的

Scientists have long known our brains need sleep to review the day's events and transfer them into longer-term memories. Students are often told to study just before turning in to maximize their recall of material for a test the next day.

科學(xué)家們早就知道，我們的大腦需要睡眠來回顧當(dāng)天發(fā)生的事情，并將其轉(zhuǎn)化為更長期的記憶。學(xué)生們經(jīng)常被要求在上床睡覺前學(xué)習(xí)，以便最大限度地回憶第二天考試的內(nèi)容。

But the exact way in which the brain stores our memories is poorly understood.

但是我們對大腦儲存記憶的確切方式知之甚少。

Now for the first time, tiny microelectrodes planted inside the brains of two people with epilepsy show just how the brain's neurons fire during sleep to "replay" our short-term memories in order to move them into more permanent storage. The study was published Tuesday in the journal Cell Reports.

現(xiàn)在，在兩名癲癇患者的大腦中植入的微型電極首次顯示了大腦神經(jīng)元如何在睡眠中激活，以“回放”我們的短期記憶，從而將它們轉(zhuǎn)移到更永久的存儲器中。這項研究發(fā)表在周二的《細(xì)胞報告》雜志上。

"This study is fascinating," said Dr. Richard Isaacson, who directs the Alzheimer's Prevention Clinic at Weill Cornell Medicine and New York-Presbyterian Hospital.

“這項研究很有意思，”理查德·艾薩克森博士說。他是威爾·康奈爾醫(yī)學(xué)院和紐約長老會醫(yī)院老年癡呆癥預(yù)防診所的負(fù)責(zé)人。

"Despite decades of research, it remains somewhat unclear how 'short-term' memories get filed away to become 'long-term' memories that can be recalled later," Isaacson, who was not involved in the study, said.

“盡管進(jìn)行了幾十年的研究，但目前仍不清楚‘短期’記憶是如何被歸檔，變成‘長期’記憶，以便日后回憶的，”艾薩克森說，他沒有參與這項研究。

"Using a brain-computer interface is an exciting way to study memory since it can record brain cell activity patterns and then look for those exact patterns later," he added.

“使用腦-機(jī)接口是研究記憶的一種令人興奮的方式，因為它可以記錄腦細(xì)胞的活動模式，然后在以后尋找那些確切的模式，”他補(bǔ)充說。

Tracking individual neurons

跟蹤單個神經(jīng)元

The study was conducted at BrainGate, an academic research consortium composed of Brown University, Stanford University and Case Western Reserve University.

這項研究是由布朗大學(xué)、斯坦福大學(xué)和凱斯西儲大學(xué)組成的學(xué)術(shù)研究機(jī)構(gòu)BrainGate進(jìn)行的。

Braingate has spent the last dozen or more years developing brain-computer interfaces that allow people with amyotrophic lateral sclerosis (ALS) and other neurologic diseases, brain injury or limb loss to be able to use their brain signals to move computer cursors, robotic arms and other assistive devices to communicate and control their world.

在過去的十幾年里，Braingate一直在開發(fā)腦-機(jī)接口，使肌萎縮性側(cè)索硬化癥(ALS)和其他神經(jīng)疾病、腦損傷或肢體喪失的患者能夠使用他們的腦信號移動計算機(jī)光標(biāo)、機(jī)械臂和其他輔助設(shè)備來交流和控制他們的世界。

"Neurons are tiny. They're about 10 microns in size," said computational neuroscientist and study author Beata Jarosiewicz. "And the macro electrodes that are approved for human use, such as the deep brain-stimulating electrodes, are too big to record the individual spiking activity of each neuron."

“神經(jīng)元是微小的。它們大約只有10微米大小，”計算神經(jīng)學(xué)家和研究作者比塔·賈羅西維奇說。“而那些被批準(zhǔn)用于人類的微距電極，比如深度刺激大腦的電極，因為太大而無法記錄每個神經(jīng)元的單個峰值活動。”

But at Braingate, surgeons implanted an array of minute electrodes onto the top of the brains of two people with sensory and motor paralysis, thus allowing the person to just "think" about moving their hand in a direction. By mapping the way the neurons behave during thought, the decoder can translate the thought into speech or into action via attached prosthetic limbs and assistive robotic devices.

但在Braingate，外科醫(yī)生們在兩名感覺和運(yùn)動癱瘓的患者的大腦頂部植入了一系列微小的電極，從而使患者能夠“思考”將手往某個方向移動。通過映射神經(jīng)元在思維過程中的行為方式，解碼器可以通過附加的假肢和輔助機(jī)器人裝置將思維轉(zhuǎn)化為語言或行動。

"Different neurons have different preferred directions," said Jarosiewicz, who was a research assistant professor at BrainGate at the time of the study.

“不同的神經(jīng)元有不同的偏好方向，”研究時擔(dān)任BrainGate研究助理教授的詹若斯維茲說。

There are some at-home monitoring devices, Isaacson said, such as wrist-worn straps and rings, which claim to track different sleep stages that may be most important for memory consolidation.

艾薩克森說，有一些家用監(jiān)控設(shè)備，比如戴在手腕上的肩帶和戒指，可以追蹤不同的睡眠階段，而這些階段對記憶的鞏固可能是最重要的。

Hopefully, he said, "future studies will help clarify which specific stages of sleep -- deep sleep, REM sleep -- in which memory replay occurs most frequently."

他說，希望未來的研究能幫助我們弄清楚睡眠的哪些特定階段——深度睡眠和快速眼動睡眠，在這些階段中，記憶重現(xiàn)的頻率最高。