Your brain really learns automatically while you sleep! The first human experimental evidence: accelerated replay by 1-4 times

I read a few pages or words before going to bed, and when I woke up, I found that I was deeply impressed.

I wonder if you have had similar experiences?

Scientists have always wanted to study this phenomenon, but they have been limited by technical conditions and have been difficult to collect weak neural activity signals in the human brain at night.

With the recent development of brain-computer interface data wireless transmission technology, the opportunity has finally arrived.

In experiments involving volunteers, researchers have obtained direct evidence for the first time that the motor cortex of the human brain "replays" daytime activity during sleep.

The first author of the paper, Daniel Rubin of Harvard Medical School, said:

What we found is incredible. He (the volunteer) basically practiced automatically all night while sleeping.

#Relevant papers have been published in The Journal of Neuroscience, a well-known journal in the field of neuroscience.

The brain speeds up learning while you sleep

This volunteer, codenamed T11, unfortunately became a quadriplegic due to spinal cord injury.

He was implanted with the invasive brain-computer interface electrodes from the BrainGate project team, which was the same set of equipment used by the T5 man who participated in the mind typing research last year.

In this experiment, T11 needs to play a simple video game during the day:

First observe the order in which the colored areas light up, and later control the cursor to move in order based on memory.

This is a classic task in brain-computer interface research. The pattern of neural activity is relatively easy to capture and identify, and has appeared in related research many times before.

For ten consecutive days, T11 needs to train from 13:45 to 16:00 in the afternoon, and sleep from 23:00 to 9:00 the next morning.

During training, the brain-computer interface can decode and record the neural activity of his brain’s motor cortex in real time.

#T11 was not told the specific content of this experiment. He just assumed that he would do recovery training as usual and fall asleep as usual at night.

But during these ten days, the researchers compared the data recorded by the brain-computer interface while he slept with the data during the day.

After processing the data using methods such as Kalman filtering, it was found that neurons at night replay training content during the day at higher frequency intervals than expected.

The firing pattern of T11 neurons during sleep is highly consistent with that during daytime training, and is even completely consistent several times.

△Data and visual demonstration starting at 0:50 in the morning

The scientific name of this phenomenon is offline replay (offline replay), which has been previously reported in mice and humans are verified while resting during the day.

This is the first time that replay during human sleep has been observed.

And the data shows that the replay speed at night is 1-4 times faster than during the day.

That is to say, when you are sleeping, your brain is not only automatically learning what you learned during the day, but also accelerating learning.

And you yourself are completely unaware of all this.

The more difficult the task, the more active the brain

There are also a series of previous studies that have respectively verified that the neural activity of the hippocampus and neocortex during mouse sleep can Practice walking the maze.

# and similar offline replay phenomena when humans are resting during the day.

After combining these findings with experimental results, the researchers proposed the idea that replay learning may be a retention mechanism that spans multiple regions of the brain. , including semantics, navigation and motion control systems. And further supports the role of sleep in memory consolidation.

In addition, this study also verified several previous important findings:

First, replay occurs mainly during slow-wave sleep in the biological sense (Slow sleep). -wave Sleep), more commonly known as non-rapid eye movement stage (Non-REM Stage), or deep sleep.

Second, replay activity is highly correlated with sharp wave ripples caused by the hippocampus.

Sharp wave ripples are rapid bursts of synchronized activity in neurons, creating a high-frequency oscillation.

△The relationship between replay and sharp wave ripples

Third, the more difficult the task practiced during the day, the stronger the replay activity during sleep.

In future plans, the research team of the BrainGate Alliance plans to systematically change the difficulty of the tasks and conduct more in-depth research.

The BrainGate Alliance is jointly launched by clinicians, neuroscientists and institutions such as Brown University, Harvard Medical School, and Massachusetts General Hospital. The goal is to use brain-computer interface technology to help patients who have lost their limb mobility due to neurological diseases or injuries. .

One More Thing

Since the brain is consolidating memories during the deep sleep stage, then during the rapid eye movement stage (that is, the stage where most dreams occur), the brain What are you doing again?

A previous paper in Science explained this.

During the rapid eye movement period, the MCH neurons in the hippocampus that are responsible for secreting melanin accumulation hormone help the brain actively forget unimportant information.

Because dreaming mainly occurs during the rapid eye movement period, when MCH neurons are active, this is one of the reasons why the content of dreams is forgotten after waking up.

So, have you ever woken up and remembered everything you read the day before?

Paper address: https://www.jneurosci.org/content/42/25/5007

Reference link:

[1]https://neurosciencenews. com/motor-replay-sleep-20906/

[2]https://www.science.org/doi/10.1126/science.aba0672

[3]https://royalsocietypublishing .org/doi/10.1098/rstb.2019.0655

[4]https://www.science.org/doi/10.1126/science.aax9238

The above is the detailed content of Your brain really learns automatically while you sleep! The first human experimental evidence: accelerated replay by 1-4 times. For more information, please follow other related articles on the PHP Chinese website!