The brain- Here is a lump of flesh-3 pounds which you can hold in the palm of your hands. It can contemplate the vastness of interstellar space, meaning of infinity, ask questions about god, its own existence etc. It is one of the greatest mystery confronting human beings. Our brain consists of 100 billion neurons. Each neuron makes 1,000-10,000 contacts with other neurons. Based on this, it is concluded that the number of permutations and combinations of brain activity exceed the number of elementary particles in the universe.
The experiment :
By attaching electrodes and eavesdroping on the behaviour of the neurons in the human brain, one recent discovery that has been made by Giacomo Rizzolatti,university of Parma has been the mirror neurons. They are found in the front of the brain(in the frontal lobes). Similar to these, ordinary motor command neurons(MCN) were known for over 50 years while the discovery of mirror neurons was made only in the 90s
Ordinary(MCN) vs Mirror Neurons:
Ordinary motor command neurons will fire if a person performs a particular action. For example if I reach out to grab an apple, MCN in the front of my brain will fire. Similarly if I reach out to pull another object, another motor command neuron will fire.
What Ritzollati found was a subset of these neurons, (20% of the number of MCN) will also fire when I see somebody else reach out for an apple. So here is a neuron(MCN) that fires when I reach out to pull an object. Also, ther is another neuron(mirror neuron) that fires when I watch my friend reach out to pull an object. This is interesting because it is almost as though this particular neuron is adopting the other person’s point of view. It is almost performing a virtual reality simulation of the other person’s action.
Mirror Neurons and its importance:
Mirror neurons are involved in imitation and emulation. To imitate a complex act requires my brain to adopt the other person’s point of view.
Humans began to exist 300-400 thousand years ago.Let’s go back 75000 years ago. There was a rapid spread and sudden emergence of a number of skills that are unique to human beings. Like- tool use, use of fire, use of shelter, use of language, ability to read someone’s mind and interpret his behaviour. All of that happened relatively quickly. Eventhough the human brain achieved its present size 300-400 thousand years ago, the emergence of skills happened very quickly only 75,000 years ago. Reputed neuroscientest Vilayanur Ramachandran claims that there was a sudden emergence of a sophisticated mirror neuron system that allowed you to emulate and imitate other people’s actions. So that when there was a sudden accidental discovery of, say – fire, by one member of the group, instead of dying out, it spread rapidly horizontally across the population or vertically down the generations. This made evolution suddenly Lamarckian instead of Darwinian. Darwinian evolution is slow and takes thousands of years. While Lamarckian is quick and geometric. Robert Greene, in his book, mastery talks about the importance of mirror neurons in helping humans become experts at a task by mere observation.
The polar bear example:
What makes humans unique? Language , definitely. But the main is culture. And a lot of culture comes from imitation. Watching your teachers do something. It has been proposed that at a key moment in our evolution, our mirror neurons got better. And that made all the difference. Once we humans got better at learning from each other, looking, copying and teaching, we could do things. Other creatures couldn’t. In other words, if you are a bear and suddenly the environment got cold, you need a few million years to develop the fur and layers of fat akin to the ones polar bear are equipped with. It would take many many bear generations to get there(Darwinian evolution) If you are human and watch your father slaying the polar bear and putting the fur on his body after skinning it off the slain bear, you observe this and learn it instantly.The next time you need to cover yourself, your mirror neurons start firing away in your brain and you perform the same complicated sequence. Instead of going through millions of years/ generations to get the fur, you’ve done it in less than a generation.
And once this is learnt, it spreads in geometric proportion across the population. This imitation of complex skills is what we call culture that forms the basis of civilization. Basic skills of hunting, fire, cooking etc have been learnt and imitated with the help of mirror neurons.
Just as there are mirror neurons for action, there are mirror neurons for touch. In other words, if somebody touches my hand, a neuron in the sensory region of my brain fires. The same neuron, in some cases, will fire when I simply watch another person being touched. This means that the mirror neuron is essentially empathizing with the other person being touched. So most of the neurons in the sensory region of my brain will fire when I am being touched (MCN). But a subset of them will also be fired when I watch somebody else being touched in the same location. So here again, you have neurons that are involved in empathy.
The question then arises that if I watch somebody being touched, why do I not get confused and literally feel that touch sensation. Merely by watching a person being touched, I empathize with the person but I don’t feel the touch. This is because you have touch and pain receptors in your skin that go back to your brain and say, “Hey don’t worry, You are not being touched.” So empathize by all means with the other person but do not actually experience the touch otherwise you will get confused. So there is this feedback signal that vetoes the signal of the mirror neuron preventing you from consciously experiencing the touch. But let’s say you remove the arm or anaesthetize the arm making it numb to sensations. If I now watch you being touched, I literally feel it in my hand. In other words, I have dissolved the barrier between you and me(touch and pain receptors).
Neuro scientest, V. Ramachandra calls these neurons- Gandhi neurons/empathy neurons. This is not in some abstract, metaphorical sense. All that is separating you from the other person is the skin. Remove the skin and you experience that person’s touch in your mind. This implies that we are all connected . There is no independent self, aloof from other human beings. We are in fact connected not just via Facebook or twitter but literally, by our neurons. There is no distinctiveness from your consciousness to mine. This is not mumbo jumbo philosophy. It stems from our basic understanding of neuro science.
The Phantom example :
Let’s say, you have a patient with a phantom limb(a sensation experienced by someone who has had a limb amputated, that the limb is still there) and he watches somebody else being touched. He feels the pain/sensation in his phantom. The astonishing thing is that if the patient has pain in his phantom limb and you squeeze/ massage the other person’s hand, this action relieves the pain in the patient’s phantom hand, almost as though the neuron were obtaining relief from merely watching somebody else being massaged.
English physical chemist CP Snow said said science and humanity will never meet. Mirror neuron system lies in the interface and helps you empathize with other human beings and adapt, learn from other human beings.
The takeaway :
The importance of mirror neurons is self-evident. There will be very little point in having a mirror system if you lived on your own. There will be a lot of point in having a digestive system if you lived on your own. There will be a good point in having a movement system if you lived on your own. There will be a good point in having a visual system if you lived on your own. But there would be no point in having the mirror system if you lived on your own. The mirror system is the most basic social brain system. It is a brain system that there is no point in having if you do not want to interact or relate to other people. Gaze into a mirror and what do you see? In your face, moods, shifts of feeling? We humans are really good at reading faces and bodies because if I can look at you and feel what you are feeling, I can learn from you, connect to you, love you. Empathy is one of the finer traits and when it happens, it happens so easily.