Part 4 (1/2)
I found Arikawa”s work fascinating, but I wondered what could drive a person to spend several decades focusing on color vision in b.u.t.terflies. I asked him about it. He replied, ”I am actually a color-blind person, and I have been interested in color vision processing in general. I wanted to know how the processing of color goes on in the brain and in the eyes. And I have really liked b.u.t.terflies ever since my childhood. I was raised as an insect guy. My father gave me nice insect nets and took me to places where I collected b.u.t.terflies and beetles.”
Arikawa said that when he was young, he had a science book for children which stated that insects in general do not see red. This was the received scientific opinion at the time. But Arikawa knew better because he had closely observed the behavior of b.u.t.terflies in his parents” garden in Tokyo: ”My mother loved flowers, and she had lots of flowers in the garden. We had huge tiger lilies and hibiscus. And I knew that these b.u.t.terflies really prefer red flowers over yellow and blue. It sounded strange to me that insects, including b.u.t.terflies, cannot see red. So that is really the first point at which I became interested in the color vision system of b.u.t.terflies.”
Arikawa has studied b.u.t.terflies for his entire professional life. He made his first contribution to science as a graduate student, back in 1979, when he discovered that b.u.t.terflies have light-sensitive neurons next to their genitals. He found that they use these ”eyes,” or photoreceptors, for correct coupling between males and females, and that females also use them to confirm that they are correctly laying eggs.
Once Arikawa settled into his academic teaching position, he went on to prove that b.u.t.terflies have color vision including red sensitivity. I asked, ”Now that you have been studying their brains and visual systems for so long, do you think they think?”
”I hope so,” he replied.
”Why do you hope so?”
He laughed. After a long pause, he said slowly: ”It”s probably a problem of the definition of the word think. They have to make decisions, in any case.” He went on to give some examples. b.u.t.terflies have to decide which flowers to visit, taking into consideration how hungry they are and which sort of food they want. Depending on circ.u.mstances, they may want something more watery than sticky nectar. He said b.u.t.terfly decision making was not simple. He paused again. We sat in silence for a while. Then he said, ”I believe that there must be some primitive form of mind in these animals, or the ability to think in things. I don”t think that a simple chain of reflexes is sufficient to explain the whole thing.”
During the silence, I thought about Arikawa thinking about b.u.t.terfly thinking. This reminded me of the story by Chuang-Tzu, the presumed founder of philosophical Taoism, who dreamed he was a b.u.t.terfly, and then no longer knew, when he awoke, whether he was Chuang-Tzu who had dreamed he was a b.u.t.terfly, or a b.u.t.terfly dreaming he was Chuang-Tzu. I asked Arikawa if anybody had studied b.u.t.terfly dreaming, or brain states a.s.sociated with dreams known as rapid eye movement (REM). He said that such studies could not be carried out because b.u.t.terfly eyes do not move, as they are fixed to the head capsule. ”Eye movement means head movement. There could be some head movement when they are sleeping, but we actually do not have a clear definition of their sleep yet. At night, they are quiet, they do not move, and they hang under leaves, so they look like they are sleeping, but I don”t know.”
Arikawa was quick to point to the limits of his knowledge. He also used words carefully, even though English is not his mother tongue. His approach to the practice of science had a well-rounded feel to it. This seemed appropriate as we were sitting in the Graduate School for Integrated Science, a university department where students learn a combination of physics, chemistry, biology, and mathematics, in order to develop the ability to produce interdisciplinary work.
True interdisciplinary approaches in science are rare. There was something about the work of j.a.panese scientists that seemed mature in this regard. I asked Arikawa what made j.a.panese science special. At first, he answered with modesty, denying that j.a.pan has any more qualities than Western countries when it comes to interdisciplinary approaches. But I knew that showing modesty is traditionally considered a virtue in j.a.pan, even when one is more experienced and knowledgeable than others. According to one j.a.panese saying, ”A clever hawk conceals its talons,” meaning to say that truly competent people do not make a show of their abilities.
I insisted on the wizardry of much j.a.panese technology and said it showed that something special was going on in j.a.panese laboratories. He laughed and said, ”I know too much about this country. So it”s very difficult for me to say what is particularly j.a.panese in comparison to other nations. But one thing I can say is that we do not hesitate to break old things. The main part of j.a.pan was totally destroyed during the last war. We discarded things and imported many new things.” He said he sometimes felt sad for the j.a.panese when he went to Europe and saw how people still live in very old buildings. He also said that the fact that most j.a.panese people do not live in old buildings gave them the advantage of ”not being trapped in old cultures.”
In deliberate reference to b.u.t.terflies, I asked whether it was fair to say that j.a.panese people like metamorphosis. He laughed and said, ”In some sense, yes. We were forced to metamorphose, by the war, and also by the natural environment, because we have plenty of volcanoes, and we have typhoons and earthquakes which destroy everything. So our old buildings can simply not survive because of nature.”
j.a.pan, a volcanic archipelago situated next to a major seabed fault, is one of the most seismically active regions of the world. Huge tidal waves, known as tsunami, often accompany the earthquakes. Hundreds of earthquakes occur every year in j.a.pan. Nature here is strong and uncontrollable. It smashes cities, floods them, blows them down. G.o.dzilla, the monster that arises from the deep sea and comes to destroy Tokyo, simply incarnates the forces of nature. The j.a.panese are used to rebuilding their world. And in Arikawa”s view, this enhances their capacity to innovate.
The typhoon was causing the window of his office to shake. Turning to the future, I asked Arikawa if his work had implications for robotics. ”Of course,” he said, ”we supply our data to robotics people, but I myself do not contribute to it directly.” This prompted me to ask what he thought about the scientific view of animals as machines. Referring to Descartes, I asked whether he saw b.u.t.terflies as machines.
”Hmmm,” he said. ”The materials which make up the b.u.t.terfly body are quite different from those of a machine. Our bodies are also machines in some sense. So we have to know that. Our minds, and the minds of b.u.t.terflies if they exist, are produced by the activity of brains. And I think that our emotions, or our thinking, all emerge from the activity of brains. So if we say that the brain is a biological machine, then b.u.t.terflies are like machines.”
”And we are, too?” I asked.
”We are, too. But our body is nothing like any presently existing machine, like computers or copying machines, or cars and airplanes. No, there is some fundamental difference. Yet I think it is also continuous, with no clear border between our system and machines. I don”t know if we can really reproduce animals by manufacturing pieces of stuff, but we biologists do want to explain how our mind is constructed, or produced, on the basis of brain activity. At least I have been trying to understand that.”
I asked how long he thought it would take people working on robotics to build a b.u.t.terfly, complete with sophisticated color vision and intricate neurology. ”The problem is that they are not aiming at producing b.u.t.terflies, or living stuff as is,” he replied. ”They want to extract certain functions from animals to use for human life. If they really tried to make this animal, for fun”” He paused. ””well, one hundred years.”
A century to make a b.u.t.terfly! Arikawa was clearly confident in the power of science. I had difficulty believing it. But I thought that if anybody was going to manage to build a b.u.t.terfly, he or she might well be j.a.panese. As British designer Andrew Davey recently remarked:, ”The miniaturization of form twinned with the maximization of function is a j.a.panese specialty. It is a hallmark of j.a.panese design.”
ARIKAWA OFFERED TO SHOW US some living b.u.t.terflies. We went downstairs and left the building. Outside, the rain was abating, though the winds were still strong. We got into his car and drove a short distance to his laboratory situated in a prefabricated single-story building. This time, we took off our shoes and put on slippers in the entrance. Arikawa showed us around the sophisticated machines that measure the spectral sensitivities of b.u.t.terfly eyes. Such research requires stripping the wings from b.u.t.terflies, tying the living insects to an apparatus, and inserting microelectrodes into their eyes. I asked Arikawa if he thought b.u.t.terflies feel pain.
”I don”t think so,” he replied, ”because they do not change behaviors when they have an injury on the eye; they do not do anything. So there is no clear sign that they are really feeling pain. At least, when you put a hole in the cornea, or break wings”b.u.t.terflies often have broken wings”it”s perfectly fine.”
I was left with doubts on this subject, remembering what Martin Giurfa had told me about bee nervous systems secreting opioids, presumably to induce a.n.a.lgesia. But I decided not to press the point. For the moment, invertebrate rights are not high on many agendas.
We walked into another room where six graduate students were working away on computers. They said nothing and concentrated on their work. Arikawa went over to a netted box containing several yellow swallowtail b.u.t.terflies and some vegetation. He grasped one around its thorax between his thumb and index finger and held it out for us to see. It had intricate and beautiful patterns on its wings.
Then Arikawa showed us some adult silkworms. These peculiar animals are moths that have been cultivated for their capacity to produce silk when they are in their larval stage. Once the males become adults, all they do is remain immobile until they smell the pheromones released by females; then they copulate. The females lay eggs. Adult silkworms never eat. They copulate, lay eggs, and die. That”s all. Arikawa placed four male silkworms on a brown piece of paper. They looked like white moths with stubby wings. They did not move at all. But when he sprayed them with a vial containing female pheromones, they buzzed into action, beating their wings and moving around in circles on the paper.
Arikawa said the silkworms had been given to him the previous day by a colleague with whom he had co-taught a public science cla.s.s. I asked if he enjoyed communicating with the general public. He replied that partic.i.p.ating in exercises of democratic science came with his job, and that he liked stimulating people”s interest in moths and b.u.t.terflies. I asked how he felt about science dealing increasingly with money, rather than free knowledge for people.
”Yes, that”s sad,” he said. ”I would say the purpose of living is to entertain ourselves, to enjoy life. So the question is: How can we enjoy life, or do what makes us happy? Making money is one of these things, so it”s important, and it makes life very convenient, by using cars and such items. But I want to put on the same list of what entertains people, enjoying music, or reading novels to stimulate your brain. And science must be regarded as music, as an important piece of social entertainment for human life. That”s why I like democratic activity.”
Later that afternoon, Beatrice and I made our way back to Tokyo. The typhoon was coming to an end. The rains had ceased. Hundreds of broken plastic umbrellas lay strewn around the waste bins in front of s.h.i.+njuku subway station. As we walked around town, the setting sun burst through an opening in the clouds and illuminated the city sky in pink and purple.
At one point we went into a store and admired the sophistication of the latest electronic gadgets. Several lifelike mechanical animals caught my attention, in particular a small green bird that chirped different melodies when the photosensitive cell on its chest was stimulated. When it sang, it moved its beak, shook its head and wagged its tail. I thought about b.u.t.terflies, with photoreceptors on their tails. And Kentaro Arikawa”s words came to mind: ”There is no clear border between ourselves and machines.” b.u.t.terflies see better than we do in some respects, though their brains are mere specks two millimeters in size. Their tiny brains can even adjust their interpretation of colors in function of light. Fancy circuitry in the b.u.t.terfly brain must be involved, but for the moment its details remain unknown.
b.u.t.terflies are transformers as they metamorphose from worm into winged insect in the pupa. People in j.a.pan are transformers, pushed by volcanoes and history to innovate and renew themselves. Shamans are transformers, changing into animals in their minds. Every living creature is a transformer, the result of a long series of transformations through evolution, which is ongoing. Every living cell is literally a transformer, transforming charges between the outside and inside of its membrane. Life itself is a transformer; it diversifies, unfolds, and morphs, and takes on as many incarnated forms as possible. And machines that act like animals are transformers, halfway between machines and living beings.
Kentaro Arikawa said there are no clear borders between ourselves and machines. He said this with complete serenity and without regrets. We ourselves are the products of the machines that are our bodies and brains, he said”without regrets, because machines can be beautiful, and have even started acting like biological creatures. As I thought about this point of view, a reformulation of Descartes” dictum came to mind: ”I think, therefore I am a machine.” But I did not agree.
Chapter 10.
MYSTERY JELLY.
After traveling to j.a.pan, I began searching for nature”s chi-sei, or capacity to know”rather than intelligence. I wanted to know how nature knows.
Bees handle abstract concepts, slime molds solve mazes, and dodder plants gauge the world around them. These species demonstrate a capacity to know, but they do not speak in human tongues and cannot tell us about their knowledge. Their capacity to know remains elusive. Humans, on the other hand, are good at talking. And we are also a natural species. h.o.m.o sapiens sapiens has a brain remarkably similar to those of other mammals. In fact the human brain has the same basic architecture as all vertebrate brains. In the absence of barriers between humans and other species, it dawned on me that I could approach nature”s capacity to know by considering how humans know.
Descartes could place only one thing above doubt, namely his own existence as a thinking subject. ”I think, therefore I am,” he wrote. This prudent stance inspired me to focus on how I know.
I thought of myself as an organism. The word comes from the Greek organon, meaning tool. As an organism, I am a kind of tool. And I have organs, which are also kinds of tools. My heart pumps, my kidneys filter, my hands grasp and look like tools. But does this mean that humans are machines?
Descartes thought so. He described the human body as a machine made of separate mechanical parts. He compared nerves, muscles, and tendons to rubber tubing. Writing in the mid”seventeenth century, he likened lungs to windmills and described the nervous system as a network of fine nets that starts in the brain and spreads from there to the rest of the body. In his book The Treatise of Man, he wrote: ”All the functions I have attributed to this machine, such as the digestion of meat, the beating of the heart and arteries, the nourishment and growth of the members, respiration, waking and sleeping, the reception by the external sense organs of light, sounds, smells, tastes, heat, and all other such qualities, the imprinting of the ideas of these qualities in the organ of common sense and imagination, the retention or imprint of these ideas in the memory”follow naturally in this machine entirely from the disposition of the organs”no more nor less than do the movements of a clock or other automaton, from the arrangement of its counterweights and wheels.”
I mulled this over and went running in the woods near my home. Autumn colors, yellow and red, were blending in with the greenery. I visualized myself as a kind of machine”a b.u.t.terfly machine moving through the landscape, perceiving colors through my eyes. I jumped over fallen trunks and branches strewn across the path. I knew my eyes had fewer photoreceptors than those of a b.u.t.terfly, but I could see well enough to run through the forest without falling down. I knew of no human-made machine capable of doing this.
Since Descartes, the mechanical view of living beings including humans has enjoyed popularity among scientists and philosophers. But living beings differ in fundamental ways from the mechanical devices built to date. We can reproduce ourselves and we can grow and transform ourselves”while computers, toasters, and automobiles are incapable of such feats. When my parents” ovum and sperm fused, they formed a single cell. This fertilized egg gradually grew into a human-shaped embryo through a series of duplications, at first into undifferentiated and nonspecialized cells, then into cells as diverse as neurons, blood cells, and skin cells. As my embryo transformed itself in this way, I came into being, a transformer from the get-go. Now, decades later, my body continues to repair its wounds and still becomes more resistant as I use it. In all of this, I am like countless other organisms and unlike the overwhelming majority of human-built devices.
True, humans are starting to design technologies that emulate the ways of nature. But so far, among all the devices made of metal alloys, silicone, plastic, and rubber, there is nothing really equivalent to living beings made of living cells. Each individual cell in a body is alive. Living cells are themselves creatures with a life cycle, and they must look after their own survival by adapting to the circ.u.mstances they encounter. This vital aspect of all biological creatures is absent in machines such as computers, the elementary particles of which are inert materials. Computers may now greatly exceed the computational capacities of humans. And they may now be endowed with ”artificial intelligence,” meaning to say that they can be programmed to do things that would otherwise require intelligence if done by a living organism. But this does not mean that machines are alive in the biological sense. It means that they can be made to exhibit certain characteristics usually a.s.sociated with life.
Some computer programs can generate informational ent.i.ties that reproduce, evolve, and mutate, all the while competing with one another. These forms of ”artificial life” function in ways comparable to living organisms. But computer programs written with sequences of ones and zeros (representing voltage on and off) cannot move around and feed themselves in the material world, and are not equivalent to living beings like bacteria, birds, and humans.
I do not know if machines know, but my impression is that I do. How does knowledge come to me? My knowing self seems to me to be lodged inside my head, behind the eyes, slightly above nostril level. And contemporary science confirms that a large part of human knowledge, including experience, sensation, and thought, is mediated by our brains.
The human brain has the consistency of jelly. According to some estimates, it contains about one hundred billion nerve cells, or neurons. Each neuron can form thousands of links with other neurons. This means that the human brain has many times more connections than stars in our galaxy. How such a complex network takes shape in an organism that originates as a single cell defies current understanding.
Scientists estimate that a cubic millimeter of the brain”s cortex”a sphere small enough to fit inside this o”contains over two miles of connecting neural ”wire” (or the extensions of neurons known as axons). I tried forming an image of this in my mind but failed repeatedly. I found this difficulty was compounded by knowing that I was using my own brain to consider the matter. Conducting an inquiry with the very object of inquiry can be tricky. The human brain can have difficulty thinking about itself.
When I look at the world around me, I see three-dimensional, color images accompanied by sensations of sound, taste, smell, and touch. These images look like they are outside my head, but they are actually a reconstruction operated by my brain. How do pictures emerge from the gelatinous matter which is my brain? How do images form inside pinkish gray jelly? The mystery is not new, and remains unsolved.
Since the 1990s, scientists have generated vast amounts of new information about the brain and mind thanks to innovations in brain-imaging techniques. Using functional magnetic resonance imaging (MRI), scientists can now peer inside the thinking, feeling brain, and see it in action. Magnetic scans work by revealing increased oxygen-rich blood flow, which occurs when a particular location of the brain is engaged in a specific task. A researcher need only put a few people into the scanner and ask them to think of an idea or behave in a given way. After subtracting the brain areas that are active in performing basic tasks, the machine depicts the brain areas critical to the task at hand as splotches of light on a screen. The neurons involved in identifying the color red, or recognizing a face, or adding a sum, or categorizing apples as fruits, light up on the screen like magic. Such research has led to a clearer understanding of the brain”s spatial organization. For instance, scientists have shown that children who learn a second language use overlapping brain areas when speaking the two languages, while those who learn the second language later in life use a distinct part of the brain for the second language. This holds true for Chinese people learning English or for Italians learning Hindi.