Thanks to Leslie Marsh of Sussex University for a video at his highly-recommended site, manwithoutqualities, for this passage by neuroscientist V. S. Ramachandra, Mirror Neurons and The Brain In the Vat:

“Iaccomo Rizzolati and Vittorio Gallasse discovered mirror neurons. They found that neurons in the ventral premotor area of macaque monkeys will fire anytime a monkey performs a complex action such as reaching for a peanut, pulling a lever, pushing a door, etc. (different neurons fire for different actions). Most of these neurons control motor skill (originally discovered by Vernon Mountcastle in the 60’s), but a subset of them, the Italians found, will fire even when the monkey watches another monkey perform the same action. In essence, the neuron is part of a network that allows you to see the world “from the other persons point of view,” hence the name “mirror neuron.”……….Dissolving the “self vs. other” barrier is the basis of many ethical systems, especially eastern philosophical and mystical traditions. This research implies that mirror neurons can be used to provide rational rather than religious grounds for ethics (although we must be careful not to commit the is/ought fallacy)……

Intriguingly, in 2000, Eric Altschuller, Jamie Pineda and I were able to show (using EEG recordings) that autistic children lack the mirror neuron system…… 

Mirror neurons also deal a deathblow to the “nature vs. nurture ” debate (I like Matt Ridley’s suggested replacement “Nature via Nurture”) for it shows how human nature depends crucially on learnability that is partly facilitated by these very circuits. They are also an effective antidote to sociobiology and pop evolutionary psychology; the assertion that the human brain is a bundle of instincts selected and fine-tuned by natural selection when our ape-like ancestors roamed the savannahs…… But, the notion that human talents and follies are governed mainly by instincts hard-wired by genes is ludicrous.

Thanks to mirror neurons the human brain became specialized for culture, it became the organ of cultural diversity par excellence. It is for this reason (rather than moral reasons or political correctness) that we need to cherish and celebrate cultural diversity. To be culturally diverse is to be human…..

I will conclude with a metaphysical question that cannot be answered by science. I cannot decide whether the question is utterly trivial or profound. I call it the “vantage point” problem foreshadowed by the Upanishads, ancient Indian philosophical texts composed in the second millennium BC, and by Erwin Schrödinger. I am referring to the fundamental asymmetry in the universe between the “subjective” private worldview vs. the objective world of physics………

…… It’s a fair assumption that the identity of your conscious experience (including your “I”) depends on the information content of your brain, “software” representing millions of years of accumulated evolutionary wisdom, your cultural milieu, and your personal memories; not on the particular atoms that currently constitute your brain…… [Lila: atoms that are replaced regularly]

Now imagine speeding up this replacement process so that I destroy your present brain and replace it with a replica/simulacrum with identical information. There would be no reason to believe your conscious experience would not continue in that other brain…..

….The possibility of multiple “minds” in a single brain is not as bizarre as it sounds. It often happens in dreams. I remember having a dream once in which another guy told me a joke and I laughed heartily even though the “other guy” was my mental invention, so I must have already known the joke all along!

The question of whether “you” would continue in multiple parallel brain vats raises issues that come perilously close to the theological notion of souls, but I see no simple way out of the conundrum. Perhaps we need to remain open to the Upanishadic doctrine that the ordinary rules of numerosity and arithmetic, of  “one vs. many”, or indeed of two-valued, binary yes/no logic, simply doesn’t apply to minds — the very notion of a separate “you ” or “I” is an illusion, like the passage of time itself.

We are all merely many reflections in a hall of mirrors of a single cosmic reality (Brahman or “paramatman”). If you find all this too much to swallow just consider the that as you grow older and memories start to fade you may have less in common with, and be less “informationally coupled”, to your own youthful self, the chap you once were, than with someone who is now your close personal friend. This is especially true if you consider the barrier-dissolving nature of mirror neurons. There is certain grandeur in this view of life, this enlarged conception of reality, for it is the closest that we humans can come to taking a sip from the well of immortality….

Will you choose the vat or the real you? This exercise might not provide an obvious answer, but fortunately none in this generation or the next will have to confront this choice. For those in the future who are forced to answer, I hope they make the “right” choice, whatever “right” means….”

NB: Again, apologies for a bit of splicing and reduction of the original passage in the interests of clarity. No meaning is altered by it, and the original is easily compared from the link.