From science fiction to reality: How far are we from a world where “what you wish for can come true”? (Part 1)

Produced by: Science Popularization China

Author: Qian Yu ( Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences )

Producer: China Science Expo

Most of the world's oldest civilizations believed in the early days that the heart was the carrier of the human spirit, that the core of feeling and thinking was located in the heart, and that the brain was just a cooling organ.

It was not until around the 20th century, with the advancement of medical technologies such as physiology and anatomy, that people gradually realized that the brain is the organ of thinking. As a result, the carrier of "thinking" in people's concepts gradually shifted from "heart" to "brain", but to "get things done", thinking alone is not enough, it must be put into practice.

Certain technologies are gradually making "wishes come true". You must have heard of this technology, which is called brain-computer interface (BCI; also known as Brain-Machine Interface, BMI). In this technology, perhaps it is more appropriate to change "wishes come true" to "brain wishes come true".

Brain-computer interface concept diagram

(Photo source: veer photo gallery)

Brain-computer interface makes "brain dreams come true"

What is a brain-computer interface? Simply put, it is connected to your brain at one end, extracting your thoughts from the dense and complex neuronal electrical signals, and connected to external devices such as computers or machinery at the other end, directly bypassing your body to convert thoughts into control signals and further execute commands. It can directly establish direct information exchange between the brain center and external devices without relying on the peripheral nerves and muscle systems of your limbs.

For example, in the picture below, as long as you want to type "hello" on the computer screen, the brain-computer interface can directly read the signal from the relevant brain area and type "hello" on the computer screen. In this process, you only need to "think" and do not need to type on the keyboard at all.

Mind Typing

(Image source: SciTechDaily)

So how far has brain-computer interface technology developed today? Let's take a brief look at its history.

In 1875, British doctor Richard Caton successfully recorded self-flowing currents in the brains of rabbits and monkeys; in 1924, German psychiatrist Hans Berger recorded human brain electrical signals on the scalp for the first time and called it electroencephalogram (EEG); in 1973, computer scientist Jacques J. Vidal from the University of California, Los Angeles formally proposed the concept of brain-computer interface.

This period of nearly a hundred years can be said to be a journey of human exploration of the feasibility of brain-computer interface technology - exploring whether humans can somehow obtain usable signals from the brain and convert them into meaningful outputs.

The conclusion is of course: Yes!

The first brain-computer interface architecture diagram

(Image source: Reference [3])

Subsequently, in the 50 years from 1973 to 2023, brain-computer interface gradually transformed from a science fiction concept into reality.

In 2000, Brazilian scientist Miguel Nicolelis and his team successfully enabled a monkey to easily control a robotic arm that did not belong to it through invasive brain-computer interface technology, using only its thoughts. Since the beginning of the 21st century, brain-computer interface technology has entered the fast lane of development.

Brain-computer interface experiments begin on humans

After the primate experiment is successful, the next step is to try it on humans.

In 2004, a US team conducted clinical trials of motor cortex brain-computer interfaces and successfully used invasive brain-computer interfaces to treat paralyzed patients, enabling a quadriplegic patient to use his mind to control the basic skills of TV remote control, computer cursor movement, and robotic arm grasping moving objects.

This marks the success of clinical trials of brain-computer interfaces on humans.

In 2014, a Brazilian patient with lower limb paralysis successfully controlled a mechanical exoskeleton with his mind and completed the opening ceremony at the World Cup. The brain-computer interface and its matching bionic exoskeleton once again came into the public eye.

Paralyzed man successfully kicks off World Cup

(Image source: newscientist)

In 2016, a patient who had been paralyzed and bedridden for ten years successfully used brain-computer interface technology to stimulate specific areas of the brain with the help of electrical signals converted from pressure, thereby achieving tactile function.

This shows that the brain-computer interface at this stage can not only output your thoughts, but also re-input sensory signals into your brain across the spinal cord, realizing two-way interaction between the brain and the external environment .

Technology explosion period : Brain-computer interface achievements are showing

After 2016, the entire field of brain-computer interface has entered a period of technological explosion . Not only has the basic research on materials and morphology of electrodes required for brain-computer interfaces made great progress, but the rapid development of artificial intelligence has also enabled the signals collected from the brain to be pre-processed and applied more effectively.

The precision of "mind-controlled" prosthetics has been further enhanced. For example, in 2019, a participant at Johns Hopkins University was able to control two prosthetic limbs at the same time by continuously adapting to two microelectrodes implanted on both sides of the brain. In 2020, a team from Zhejiang University enabled a quadriplegic to accurately control external robotic arms and hands, and to accurately perform basic movements such as eating and shaking hands.

Of course, in addition to advances in motion-assisted therapy, brain-computer interface technology in the field of language recovery has also shined .

In June 2023, Huashan Hospital affiliated to Fudan University in my country took the lead in releasing a neural network model suitable for Chinese. It can decode Chinese vocabulary tones and basic syllables from intracranial recordings and combine them to generate speech. Through brain-computer interface technology, it helps patients with tonal language pronunciation disorders or aphasia to express their "inner voice" directly.

The brain-computer interface developed by the research team of Huashan Hospital affiliated to Fudan University was successfully published in Science Advances

(Image source: Science Advances magazine)

In August of the same year, a research team from the University of California, San Francisco, used an invasive brain-computer interface to help two patients with slurred speech due to severe amyotrophic lateral sclerosis communicate with others with higher accuracy and a more moderate speaking speed.

General paralysis or language disorders are just physical illnesses, and current brain-computer interface technology has also demonstrated its powerful function in treating mental illness.

In 2021, researchers at the University of California relieved a patient with major depressive disorder by implanting a neural pacemaker in her brain.

At the end of 2020, a hospital in my country established a clinical research team on "Brain-computer interface treatment for refractory depression" and implanted a brain pacemaker with brain-computer interface function in the brains of patients with depression. So far, 23 patients with depression have completed the treatment, and their depression has improved by an average of 60%.

Conclusion

Brain-computer interface technology is moving from science fiction to reality, from the initial animal experiments in the laboratory to commercial medical human trials. It is exciting to think about what kind of future this "brain" technology will bring.

Of course, the main factor restricting the development of brain-computer interface technology is that we do not have a comprehensive understanding of the working mechanism of the brain . Brain science is one of the most complex and unsolved mysteries in natural science.

Research on brain-computer interfaces is still ongoing. How do brain-computer interfaces achieve the control of objects through "telepathy"? What is the current research focus of this technology? What is the future development direction? We will share with you in the next article.

References:

[1]Caton, Richard. 'The electric currents of the brain'. British Medical Journal, 2 (1875)

[2]Evarts EV. Relation of pyramidal tract activity to force exerted during voluntary movement. J Neurophysiol. 1968 Jan;31(1):14-27.

[3]Vidal JJ. Toward direct brain-computer communication. Annu Rev Biophys Bioeng. 1973; 2:157-80.

[4]Nicolelis MA, Chapin JK. Controlling robots with the mind. Sci Am. 2002 Oct;287(4):46-53.

[5]Hochberg LR, Serruya MD, Friehs GM, Mukand JA, Saleh M, Caplan AH, Branner A, Chen D, Penn RD, Donoghue JP. Neuronal ensemble control of prosthetic devices by a human with tetraplegia. Nature. 2006 Jul 13;442(7099):164-71.

[6]Liu Y, Zhao Z, Xu M, Yu H, Zhu Y, Zhang J, Bu L, Zhang X, Lu J, Li Y, Ming D, Wu J. Decoding and synthesizing tonal language speech from brain activity. Sci Adv. 2023 Jun 9;9(23):eadh0478.

[7] Scangos, KW, Khambhati, AN, Daly, PM, Makhoul, GS, Sugrue, LP, Zamanian, H., Liu, TX, Rao, VR, Sellers, KK, Dawes, HE, Starr, PA, Krystal, AD, Chang, EF, 2021. Closed-loop neuromodulation in an individual with treatment-resistant depression. Nat Med 27(10), 1696-1700