The brain: 3 pounds, you could hold it in the palm of your hand… but it can contemplate the vastness of the universe, the reason for its own existance or why I am writing this post at midnight when I need to be up at 5am tomorrow.
How?
There are 100 billion neurons in the adult human brain, each with between 1,000 and 10,000 connections. (That’s lots).
Giacomo Rizzolatti discovered the existence of mirror neurons in the late 1990s in the frontal lobes of macaque monkeys, and later confirmed their existence in the human brain. About 20% of the neurons in the front, intentional, human cortex are these mirror neurons. Leading neuro-scientists including V.S. Ramachandran (great TED talk here) consider mirror neurons one of the most important recent discoveries in neuroscience.
The majority of the human frontal lobe is made up of motor neurons. Motor neurons fire when I reach out and grab something. Mirror neurons fire when I watch somebody else reach out and grab something.
For 400,000 years the human brain has had its current shape and form, but something arose 75,000 years ago that allowed the extremely rapid spread of human culture, allowing “The Great Leap Forward” in human society – the emergence and rapid spread of human culture – tool use, language, shelter, theory of mind. Some speculate that the development of 20% of frontal lobe dedicated to mirror neurons was what allowed the rapid spread of culture – humans could learn not just from doing, but from watching somebody else doing.
There are mirror neurons for action, also for touch. These motor neurons will fire simply when I watch somebody else being touched.
How do I not get confused?
Touch and pain receptors “veto” the mirror neuron. But, if my arm is anaesthetised or if I have lost my limb, the touch and pain receptors do not veto and I will feel the sensation of touch even though it is only that I am watching another person being touched. This happens to people who have lost a limb in traffic accidents.
So there actually is some type of universal consciousness – I am feeling what my neighbours are feeling. I am emersed in a some sort of meta-social type of consciousness. “This is not mumbo-jumbo philosophy, this emerges from neuroscience” VS Ramachandran.
The thought is that the existence of these mirror neurons will start to allow us to understand how consciousness arises. Some say that psychology/neuroscience will be to this century what physics was to the last.
What will be the 20XX advances in neuroscience that compare to the 19XX advances such as radio, industrialization, electrical power or nuclear energy?
