I'd like to talk to you today about the human brain, which is what we do research on at the University of California. Just think about this problem for a second. Here is a lump of flesh, about three pounds, which you can hold in the palm of your hand. But it can contemplate the vastness of interstellar space. It can contemplate the meaning of infinity, ask questions about the meaning of its own existence, about the nature of God.
Quero falarlles hoxe do cerebro humano, sobre o cal investigamos na Universidade de California. Pensen no seguinte problema por un intre. Aquí teñen un pedazo de carne de 1,3 kg de peso que poden vostedes soster na palma da man. Pero pode concibi-la inmensidade do espacio interestelar. Pode concibi-lo infinito e facerse preguntas sobre o significado da súa existencia, sobre a natureza de Deus.
And this is truly the most amazing thing in the world. It's the greatest mystery confronting human beings: How does this all come about? Well, the brain, as you know, is made up of neurons. We're looking at neurons here. There are 100 billion neurons in the adult human brain. And each neuron makes something like 1,000 to 10,000 contacts with other neurons in the brain. And based on this, people have calculated that the number of permutations and combinations of brain activity exceeds the number of elementary particles in the universe.
É, sen dúbida, a cousa máis abraiante do mundo. O maior misterio ó que se enfrontan os seres humanos. ¿Como ocorre isto? Como saben, o cerebro está formado por neuronas. Aquí vemos unhas neuronas. Hai 100 mil millóns de neuronas nun cerebro humano adulto. E cada neurona establece entre 1.000 e 10.000 contactos con outras neuronas. Baseándose nisto, calculouse que o número de permutacións e combinacións da actividade cerebral supera a cantidade de partículas elementais no universo.
So, how do you go about studying the brain? One approach is to look at patients who had lesions in different part of the brain, and study changes in their behavior. This is what I spoke about in the last TED. Today I'll talk about a different approach, which is to put electrodes in different parts of the brain, and actually record the activity of individual nerve cells in the brain. Sort of eavesdrop on the activity of nerve cells in the brain.
¿Como podemos estudiar o cerebro? Un enfoque consiste en observar a pacientes con lesións en diferentes partes do cerebro e estudiar os cambios no seu comportamento. Falei disto no último encontro de TED. Hoxe falarei dun enfoque distinto: poñer electrodos en diferentes partes do cerebro e grava-la actividade de células nerviosas individuais. É como axexar a actividade das células nerviosas do cerebro.
Now, one recent discovery that has been made by researchers in Italy, in Parma, by Giacomo Rizzolatti and his colleagues, is a group of neurons called mirror neurons, which are on the front of the brain in the frontal lobes. Now, it turns out there are neurons which are called ordinary motor command neurons in the front of the brain, which have been known for over 50 years. These neurons will fire when a person performs a specific action. For example, if I do that, and reach and grab an apple, a motor command neuron in the front of my brain will fire. If I reach out and pull an object, another neuron will fire, commanding me to pull that object. These are called motor command neurons that have been known for a long time.
Un descubrimento recente feito por investigadores italianos, de Parma, Giacomo Rizzolatti e os seus colegas, é un grupo de neuronas chamadas "neuronas espello", que están nos lóbulos frontais do cerebro. Resulta que hai unhas neuronas chamadas neuronas motoras na parte frontal do cerebro, coñecidas dende hai máis de 50 anos. Estas neuronas actívanse ó realizares unha acción determinada. Por exemplo, se eu fago isto e collo unha mazá, activarase unha neurona motora na parte frontal do meu cerebro. Se collo un obxecto, activarase outra neurona, ordeándome coller ese obxecto. Son as neuronas motoras, coñecidas dende hai moito tempo.
But what Rizzolatti found was a subset of these neurons, maybe about 20 percent of them, will also fire when I'm looking at somebody else performing the same action. So, here is a neuron that fires when I reach and grab something, but it also fires when I watch Joe reaching and grabbing something. And this is truly astonishing. Because it's as though this neuron is adopting the other person's point of view. It's almost as though it's performing a virtual reality simulation of the other person's action.
Pero o que Rizzolatti achou foi que un subconxunto destas neuronas, arredor dun 20% delas, activarase tamén cando eu estea a mirar a outra persoa que fai a mesma acción. Temos aquí unha neurona que se activa cando eu alcanzo e collo algo, pero tamén cando vexo a outro individuo alcanzar e coller algo. Isto é realmente abraiante. É como se esta neurona estivera adoptando o punto de vista da outra persoa. É case coma se estivera facendo unha simulación de realidade virtual da acción da outra persoa.
Now, what is the significance of these mirror neurons? For one thing they must be involved in things like imitation and emulation. Because to imitate a complex act requires my brain to adopt the other person's point of view. So, this is important for imitation and emulation. Well, why is that important? Well, let's take a look at the next slide. So, how do you do imitation? Why is imitation important? Mirror neurons and imitation, emulation.
Ben, ¿cal é a importancia destas neuronas espello? Alomenos teñen que estar implicadas na imitación e na emulación. Porque imitar unha acción complexa require que o meu cerebro adopte o punto de vista da outra persoa. Polo tanto, é importante na imitación e na emulación. ¿Por que é tan importante? Botemos unha ollada á seguinte diapositiva. ¿Cómo se produce a imitación? ¿Por que é importante? As neuronas espello e a imitación, a emulación.
Now, let's look at culture, the phenomenon of human culture. If you go back in time about [75,000] to 100,000 years ago, let's look at human evolution, it turns out that something very important happened around 75,000 years ago. And that is, there is a sudden emergence and rapid spread of a number of skills that are unique to human beings like tool use, the use of fire, the use of shelters, and, of course, language, and the ability to read somebody else's mind and interpret that person's behavior. All of that happened relatively quickly.
Consideremos a cultura, o fenómeno da cultura humana. Retrocedamos no tempo entre [75.000] e 100.000 anos. Analizando a evolución humana, algo moi importante ocorreu fai 75.000 anos. Houbo unha aparición repentina e un espallamento inmediato dunha serie de aptitudes propias dos seres humanos, como o uso de ferramentas, o aproveitamento do lume, o uso de refuxios e, por suposto, a linguaxe e a habilidade de ler a mente doutra persoa e interpreta-la súa conducta. Todo isto tivo lugar dun xeito relativamente rápido.
Even though the human brain had achieved its present size almost three or four hundred thousand years ago, 100,000 years ago all of this happened very, very quickly. And I claim that what happened was the sudden emergence of a sophisticated mirror neuron system, which allowed you to emulate and imitate other people's actions. So that when there was a sudden accidental discovery by one member of the group, say the use of fire, or a particular type of tool, instead of dying out, this spread rapidly, horizontally across the population, or was transmitted vertically, down the generations.
Incluso considerando que o cerebro acadara o seu tamaño actual fai case 300 ou 400.000 anos, fai 100.000 anos todo isto ocorreu moi moi rápido. E defendo que o que ocorreu foi o xurdimento súbito dun sistema sofisticado de neuronas espello, que nos permitiu emular e imitar as acción doutros individuos. Cando un membro do grupo facía un descubrimento accidental e repentino, por exemplo o uso do lume ou dunha ferramenta determinada, en lugar de desaparecer espallábase con rapidez, de xeito horizontal pola poboación ou transmitido verticalmente entre xeracións.
So, this made evolution suddenly Lamarckian, instead of Darwinian. Darwinian evolution is slow; it takes hundreds of thousands of years. A polar bear, to evolve a coat, will take thousands of generations, maybe 100,000 years. A human being, a child, can just watch its parent kill another polar bear, and skin it and put the skin on its body, fur on the body, and learn it in one step. What the polar bear took 100,000 years to learn, it can learn in five minutes, maybe 10 minutes. And then once it's learned this it spreads in geometric proportion across a population.
Isto fixo que a evolución fora lamarckiana, non darwiniana. A evolución darwiniana é lenta; prodúcese ó longo de centos de miles de anos. Un oso polar, para desenvolver a súa pel, precisa miles de xeracións, quizais 100.000 anos. Un rapaz humano simplemente contempla ó seu proxenitor matar un oso polar, esfolalo e poñe-la pel sobre o seu corpo, e aprende isto nun só paso. O que ó oso polar lle levou 100.000 anos aprender, o ser humano apréndeo en 5, quizais 10 minutos. Unha vez que o aprende, espállase en proporción xeométrica por unha poboación.
This is the basis. The imitation of complex skills is what we call culture and is the basis of civilization. Now there is another kind of mirror neuron, which is involved in something quite different. And that is, there are mirror neurons, just as there are mirror neurons for action, there are mirror neurons for touch. In other words, if somebody touches me, my hand, neuron in the somatosensory cortex in the sensory region of the brain fires. But the same neuron, in some cases, will fire when I simply watch another person being touched. So, it's empathizing the other person being touched.
Isto é básico. A imitación de aptitudes complexas é o que chamamos cultura e é a base da civilización. Pero hai outra clase de neuronas espello que actúa en algo moi diferente. Existen neuronas espello, así como existen neuronas espello para acción, hai neuronas espello para o tacto. Noutras palabras, se alguén me toca a man, actívase unha neurona do córtex somatosensorial da área sensorial do cerebro. Pero nalgúns casos a mesma neurona activarase soamente con ver cómo tocan a outra persoa. Está empatizando coa persoa á que están a tocar.
So, most of them will fire when I'm touched in different locations. Different neurons for different locations. But a subset of them will fire even when I watch somebody else being touched in the same location. So, here again you have neurons which are enrolled in empathy. Now, the question then arises: If I simply watch another person being touched, why do I not get confused and literally feel that touch sensation merely by watching somebody being touched? I mean, I empathize with that person but I don't literally feel the touch. Well, that's because you've got receptors in your skin, touch and pain receptors, going back into your brain and saying "Don't worry, you're not being touched. So, empathize, by all means, with the other person, but do not actually experience the touch, otherwise you'll get confused and muddled."
A maioría delas activaranse cando me tocan en distintas zonas. Neuronas diferentes para zonas diferentes. Pero un subconxunto delas activarase incluso cando vexa a alguén ó que están a tocar no mesmo lugar. De novo vemos neuronas involucradas na empatía. Xorde entón unha pregunta: se eu observo a outra persoa á que están a tocar, ¿por qué non me confundo e sinto literalmente a sensación táctil por ver a alguén que está sendo tocado? Quero dicir que, aínda que empatizo con ela, non sinto literalmente o tacto. Isto é debido a que temos receptores na nosa pel, receptores do tacto e da dor, volvendo ó cerebro e dicíndolle "non te preocupes, non te están a tocar. Empatiza, por suposto, coa outra persoa, pero non experimentes o tacto ou atordoaraste".
Okay, so there is a feedback signal that vetoes the signal of the mirror neuron preventing you from consciously experiencing that touch. But if you remove the arm, you simply anesthetize my arm, so you put an injection into my arm, anesthetize the brachial plexus, so the arm is numb, and there is no sensations coming in, if I now watch you being touched, I literally feel it in my hand. In other words, you have dissolved the barrier between you and other human beings. So, I call them Gandhi neurons, or empathy neurons. (Laughter)
Temos entón un sinal de retroalimentación que veta o sinal da neurona espello, evitando que experimentemos ese tacto de forma consciente. Pero se eliminamos o brazo, se simplemente mo anestesian, poñéndome unha inxección e anestesiando o plexo braquial de modo que o brazo entumécese e non experimenta ningunha sensación, se agora vexo que alguén lles toca, síntoo literalmente na miña man. Noutras palabras, disolvemos a barreira entre vostedes e os demais seres humanos. Por iso as chamo neuronas Gandhi, ou neuronas empáticas. (Risas)
And this is not in some abstract metaphorical sense. All that's separating you from him, from the other person, is your skin. Remove the skin, you experience that person's touch in your mind. You've dissolved the barrier between you and other human beings. And this, of course, is the basis of much of Eastern philosophy, and that is there is no real independent self, aloof from other human beings, inspecting the world, inspecting other people. You are, in fact, connected not just via Facebook and Internet, you're actually quite literally connected by your neurons. And there is whole chains of neurons around this room, talking to each other. And there is no real distinctiveness of your consciousness from somebody else's consciousness.
E non é ningunha metáfora abstracta: o único que os separa a vostedes deles, doutras persoas, é a súa pel. Se eliminamos a pel, vostedes experimentan o tacto desa persoa na súa mente. Disolveron a barreira entre vostedes e os demais seres humanos. Ista é, por suposto, a base da mayoría da filosofía oriental, que di que non hai un eu independente, alonxado dos outros seres humanos, analizando o mundo, analizando á xente. Vostedes están conectados no só a través do Facebook e internet, senón real e literalmente conectados a través das súas neuronas. Hai cadeas enteiras de neuronas nesta sala, falando unhas con outras. Non hai distinción real entre as súas consciencias e as consciencias dos demais.
And this is not mumbo-jumbo philosophy. It emerges from our understanding of basic neuroscience. So, you have a patient with a phantom limb. If the arm has been removed and you have a phantom, and you watch somebody else being touched, you feel it in your phantom. Now the astonishing thing is, if you have pain in your phantom limb, you squeeze the other person's hand, massage the other person's hand, that relieves the pain in your phantom hand, almost as though the neuron were obtaining relief from merely watching somebody else being massaged.
Non é unha filosofía barateira. Xorde da nosa comprensión da neurociencia básica. Por exemplo, temos un paciente cun membro pantasma. Se lles quitaron un brazo e vostedes teñen un membro pantasma e miran a alguén ó que están a tocar, sentirano no seu membro pantasma. O máis abraiante é que, se vostedes sinten dor no su membro pantasma e alguén apreta, masaxea a man doutra persoa, cálmase a dor dos seus membros pantasma, case como se as neuronas estiveran acadando un acougo só por ver a alguén recibindo unha masaxe.
So, here you have my last slide. For the longest time people have regarded science and humanities as being distinct. C.P. Snow spoke of the two cultures: science on the one hand, humanities on the other; never the twain shall meet. So, I'm saying the mirror neuron system underlies the interface allowing you to rethink about issues like consciousness, representation of self, what separates you from other human beings, what allows you to empathize with other human beings, and also even things like the emergence of culture and civilization, which is unique to human beings. Thank you. (Applause)
Ben, aquí teñen a miña última diapositiva. Durante moito tempo, a xente facía distinción entre ciencia e humanidades. C.P. Snow falou das dúas culturas: a ciencia por un lado, as humanidades polo outro; os xemelgos nunca se atoparán. Eu defendo que o sistema das neuronas espello subxace na interacción, permitíndonos reconsiderar cuestións como a conciencia, a representación do eu, o que nos separa doutros seres humanos, o que nos permite empatizar con outros seres humanos e incluso cuestións como o xurdimento da cultura e a civilización, que son propias dos seres humanos. Gracias. (Aplausos)