Name: 脳とコンピュータのインターフェース - 脳の謎 (Brain-Computer Interface - Mysteries of the Brain)
Uploaded: 2021-01-14T06:35:54.000Z
Duration: 4 min 55 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

程度の副詞

TOM COSTELLO: Imagine moving a mechanical arm by just thinking

様態の副詞

about it. Or playing a video game using only your mind.

Although it may seem like science fiction, scientists and

engineers have been developing this technology for decades:

it's called brain-computer interface, or BCI.

RAJESH RAO: The field of brain-computer interfaces relies

on the ability of the brain to be able to generate certain

types of responses that can then be harnessed by computers, to be

COSTELLO: Doctor Rajesh Rao is a neuroengineer and director of

the Center for Sensorimotor Neural Engineering at the

University of Washington, and is funded by the National Science

Foundation. He is developing safe, non-invasive devices that

can connect to the brain to accomplish things like

controlling a prosthetic arm, or sending commands to a computer.

RAO: Looking at the development of this whole

field of brain-computer interfaces is to think of it in

terms of studying how the brain controls the body.

COSTELLO: Whether it's telling the legs to jump in the air, or

activating glands to produce sweat, the body's actions and

functions are controlled by neurons. They communicate

information to and from the brain and the rest of the

nervous system using chemical and electrical signals.

RAO: And so they're sending these electrical pulses to each

other and eventually to the muscles that are then

COSTELLO: Much like how the brain controls muscles,

researchers can use new technologies to tap into these

RAO: The understanding of how the brain controls movement led

to the development of devices and algorithms - that can be

implemented on a computer that recognize these patterns in the

activity of brain cells and then correspondingly move

COSTELLO: To demonstrate how this technology works, Rao and

his team of students use a BCI that allows them to study

nonverbal communication. First, the student is fitted with an

electroencephalogram or EEG cap, which is a series of electrodes

placed on the scalp to record brain signals.

COSTELLO: When a question appears on the monitor, the

student answers "yes" or "no" by looking at one of the flashing

lights, which are blinking at different frequencies. When the

subject's eyes focus on one of the response lights, the

frequency of that specific light is picked up by the visual

cortex in the brain, and measured by the EEG cap. 12

hertz represents a "yes" frequency, while a "no" is at

STUDENT: Now you can see it peak here at around 12 hertz because

COSTELLO: The computer interprets this signal and moves

the cursor in the direction of the response. Using an EEG cap

isn't the only way to measure brain activity. Some BCI's use a

method called electrocorticography. It also

records brain activity but unlike the EEG cap, it is

surgically placed directly on the surface of the brain,

providing a clearer signal and more precise information.

RAO: For example, they can imagine moving their hand. And

we use a computer to extract the patterns that correspond to

imagined movement of the hand compared to, for example,

COSTELLO: From there, the computer can distinguish the two

types of brain activity: imagining movement and not

imagining movement, then use that information to enable hand

RAO: Given the right kinds of information and the right kinds

of devices that are useful for the animal or for the human,

COSTELLO: With practice, the brain can learn to do something

it's never done before, like control a prosthetic it's not

familiar with. But the key is to understand how these neural

networks communicate between the brain and the body.

RAO: If you're able to understand the brain better,

then you're also able to build better brain-computer

interfaces, because they can use those signals that are

responsible for different kinds of movements.

COSTELLO: As Rao continues to collaborate with engineers,

neuroscientists, and neurosurgeons to develop more

BCI devices, he is working toward a future where the brain