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The Brain,
the Body's Last Frontier

This computer graphics image of brain activity was produced using data collected by magnetoencephalography.

The life sciences are expected to achieve remarkable progress in the twenty-first century. The foremost object of interest of people around the world is the science of the brain, the field where researchers explore what makes the human being human. Here we look into the state of the art in this domain through visits to two Aichi institutions: the National Institute for Physiological Sciences, located in Okazaki and known for its vanguard research into the human brain, and the Chukyo University School of Computer and Cognitive Sciences, located in Toyota and engaged in research into the other famous brain: the silicon chip.

What is the brain? | The front line of brain science |
Artificial intelligence, the other brain

What is the brain?

Regenerative medicine aims to produce organs of the body by cultivating cells extracted from it for the purpose of transplants back into the donor. This technology is still at the stage of basic research, but some day patients and doctors may engage in exchanges of the following sort:

Patient: "Doctor, I've reached the age of 234, and thanks to regenerative medicine I'm feeling physically fit. But recently I've become forgetful, and sometimes I find thinking troublesome. Isn't it about time for you to replace my brain?" Doctor: "That's a difficult request. We can take out organs like the heart and stomach and put new ones back in, and we also know how to culture the brain's nerve cells. But if we gave you a new brain, you would cease to be you."

Patient: "What do you mean? Surely it would be my own brain, since you would make it from my own cells."

Doctor: "Quite right. The cells, when considered one by one, would unmistakably be your cells. But that doesn't mean that the brain organized from the cells would necessarily be your brain."

Patient: " . . . "

Doctor: "The brain doesn't just keep your autonomic nervous system going but also is responsible for memory, recognition, thought, judgment, emotions, and so forth. Each of these is a vital component of the individual's personality. Scientists say the way the brain's nerve cells are organized into networks influences how we think and feel, for instance. When the brain is operated on, changes in the networks can drastically alter even the individual's values, view of life, and view of the world. In an extreme case, the result of the operation could be the birth of a personality entirely different from who you are now."

Patient: "So I'm still me if I have my heart or stomach replaced, but I wouldn't be me if my brain were replaced? Since the brain is just an organ, that seems most mys-terious."

Doctor: "That's what sets the brain apart from all the other organs." Patient: "It's an enigmatic part of the body indeed."

This is, of course, a rather fantastic exchange, but it should serve to show what an extraordinary thing the brain is.

The front line of brain science

The brain is an extremely complex organ incorporating networks of some 30 billion nerve cells, each of which has more than 1,000 synapses, or connections to other cells. Within the brain are the puzzling mechanisms involved in such mental activities as memory, recognition, thought, judgment, and emotion. Given this, it is said that in order to understand the brain, we must not only elucidate both its structure and its mechanisms but also confirm how these two aspects relate to each other.

How much progress has research into the brain managed to achieve? "Even if we set aside fields like psychology and consider just the domain of the natural sciences," comments Kunihiko Obata, a professor in the Laboratory of Neurochemistry of the National Institute for Physiological Sciences in Okazaki, "years and years will be needed before we can come up with a whole picture of the brain."

This institute is engaged in cutting-edge research into the physiology of the human being and has established a position as one of Japan's foremost centers for research into the brain. The contributions it has made to the study of the sense of pain in particular have gained international recognition.

The magnetoencephalograph meter at the institute. It measures the faint magnetic fields generated by current flows moving through the brain's neurons, and thus it permits external observation of such brain functions as pain sensation, sight, speech, and memory.

The understanding of neurons, or nerve cells, has grown much deeper, as Obata observes: "The past two or three decades have seen great progress in brain science. We know quite a bit about the basics of neuron networks. Also, with respect to how the brain orders the body to move and how it sees things, we've learned perhaps half of what there is to know. But when it comes to emotions, judgments, thoughts, and the like, there are unanswered questions everywhere. We've narrowed down the places in the brain responsible for feelings and so forth, but we don't know what networks are involved or what mechanisms are operating them. These are tasks for the future."

In the case of nervous disorders caused by disruption of the transmission of stimuli through neurons, increasingly effective remedies are being developed around the world. But for diseases deriving from the mechanisms of the brain's networks, such as mental disorders involving emotion and reasoning, effective means of treatment have yet to be found. In short, researchers are on their way to clarifying the brain's structure, but they have only moved past the threshold of the door to the brain's mechanics, and the interrelations between the two are still shrouded in mystery.

"If brain science is to make a large leap forward," Obata continues, "researchers in a variety of specialties must take studies dealing with the brain much further. Scientists must pool their data with people in other specialties and gather together for ongoing discussion. Brain science is one of the life sciences in which quick results are not to be expected. The key is to build up a store of low-profile endeavors over a long time span."

Artificial intelligence, the other brain

Another approach to brain research is being attempted in a field that traditionally has been thought to have only a slim connection to the life sciences. This is artificial intelligence. Generally stated, artificial intelligence is concerned with computers and robots possessing intellectual faculties. To put it even more simply, AI deals with computers and robots that can think and make decisions like human beings do.

The Chukyo University School of Computer and Cognitive Sciences in Toyota is engaged in sophisticated research and development in the AI field. The school's work on mimicking such capabilities of the human brain as memory, recognition, thought, judgment, and emotion has attracted attention at home and abroad for the new possibilities it has opened up in artificial intelligence.

Teruo Fukumura is an engineer serving the school as a special advisor. He explains the direction the school has taken in its AI program: "Thus far research into artificial intelligence has sought to understand language and concepts and create the ability to reason, but henceforth it will also have other goals, such as developing the ability to display behavior directly appealing to human emotions. This is because development of interfaces becomes more important the closer the relationship between the human being and the computer or robot grows."

Interest in Japan is currently focused on robot technologies, especially humanoid robotics. The rapid graying of Japanese society is creating an acute need for extra hands for nursing and medical care and even for housework, and humanoids and other robots are expected to be able to help meet this need. Toward this end, assorted methodologies are being worked out to facilitate the interaction between humans and robots, that is, to fashion interfaces with a realistic touch.

Computer simulations of body movement are displayed on the screen. Software representations of body parts like bones, muscles, and fat are programmed into the computer to see how they change as the body moves. This can be seen as research to acquaint artificial intelligence with body movements.

Among the school's goals are the development of robots that can walk together with people based on analyses of human walking movements, the development of programs that can tell which of two soccer teams playing a game is superior to the other based on readings of the flow of the game, and the creation of bust-fabrication systems producing likenesses close to those the brain recognizes based on exaggeration of the distinguishing features of the face.

"To be sure," Fukumura explains, "artificial intelligence need not necessarily be provided with mechanisms exactly like those of the brain. But for AI to comprehend human intuition and sensitivity, we ourselves have to learn more about the brain's mechanisms for things like recognition and emotion. This will open the way to building good interfaces. There's a big gap now, but the distance between AI and the brain should narrow in the future."

On the silicon chip can be built a brain with a structure entirely different from the human brain. But what sort of light may AI research throw on the field of brain science, said to be the last frontier of the human body? Just possibly Aichi Prefecture, which has one of the world's most highly concentrated collections of industrial production technology, as well as plenty of human talent may become the springboard of the next leap forward in brain science.

(Photos by Tadashi Aizawa, Text by Masahiro Ota)