On 10/08/2006, Dennis Rivers kindly wrote:

Dear Evelin,

Thank you so much for the birthday card you sent me.
...

One of the big recent discoveries in neuropsychology is the existence of "mirror neurons," which supports the idea that perception includes a strong element of mental re-enactment. If you Google for "mirror neurons" you will find many articles. I am wondering what the implications of this might be for humiliation studies, especially as relates to contagion processes, when the culture of humiliation spreads through an organization or school.
...
Right now in Sri Lanka, under the extreme stress of war, people all over the island are starting to see the same glowing colors emanating from the heart region of their local Buddha statue. So there are both positive and negative social contagions, but the positive ones are much rarer, something like seeing a double rainbow in the sky!

Many blessings,

Dennis

Dear Dennis!
I googled "Mirror Neurons" and found the following article to be particularly well written and informative:

MIRROR NEURONS and imitation learning as the driving force behind "the great leap forward" in human evolution
By V.S. Ramachandran
http://www.edge.org/3rd_culture/ramachandran/ramachandran_p1.html

V.S. RAMACHANDRAN is professor of Neuroscience and Psychology and Director of Center for Brain and Cognition at the University of California at San Diego. He also holds joint appointments at the Salk Institute in La Jolla and with the Cognitive Sciences Program at UCSD. He is also a physician. A dynamic speaker who rolls his r's and flourishes vowels, Dr. Ramachandran gives scientific talks the world over. His book Phantoms In The Brain (with Sandra Blakeslee) was selected as one of the best books of 1998 by The Economist and was a finalist for the Los Angeles Times Book Prize. It was on the "Editors Choice" list in Scientific American, Discover Magazine and The American Scientist.

The discovery of mirror neurons in the frontal lobes of monkeys, and their potential relevance to human brain evolution — which I speculate on in this essay — is the single most important "unreported" (or at least, unpublicized) story of the decade. I predict that mirror neurons will do for psychology what DNA did for biology: they will provide a unifying framework and help explain a host of mental abilities that have hitherto remained mysterious and inaccessible to experiments.

There are many puzzling questions about the evolution of the human mind and brain:

1) The hominid brain reached almost its present size — and perhaps even its present intellectual capacity about 250,000 years ago . Yet many of the attributes we regard as uniquely human appeared only much later. Why? What was the brain doing during the long "incubation "period? Why did it have all this latent potential for tool use, fire, art music and perhaps even language- that blossomed only considerably later? How did these latent abilities emerge, given that natural selection can only select expressed abilities, not latent ones? I shall call this "Wallace's problem", after the Victorian naturalist Alfred Russell Wallace who first proposed it.

2) Crude "Oldawan" tools — made by just a few blows to a core stone to create an irregular edge — emerged 2.4 million ago and were probably made by Homo Habilis whose brain size was half way (700cc) between modern humans (1300) and chimps (400). After another million years of evolutionary stasis aesthetically pleasing "symmetrical" tools began to appear associated with a standardization of production technique and artifact form. These required switching from a hard hammer to a soft (wooden?) hammer while the tool was being made, in order to ensure a smooth rather than jagged, irregular edge. And lastly, the invention of stereotyped "assembly line" tools (sophisticated symmetrical bifacial tools) that were hafted to a handle, took place only 200,000 years ago. Why was the evolution of the human mind "punctuated" by these relatively sudden upheavals of technological change?

3) Why the sudden explosion (often called the "great leap" ) in technological sophistication, widespread cave art, clothes, stereotyped dwellings, etc. around 40 thousand years ago, even though the brain had achieved its present "modern" size almost a million years earlier?

4) Did language appear completely out of the blue as suggested by Chomsky? Or did it evolve from a more primitive gestural language that was already in place?

5) Humans are often called the "Machiavellian Primate" referring to our ability to "read minds" in order to predict other peoples' behavior and outsmart them. Why are apes and humans so good at reading other individuals' intentions? Do higher primates have a specialized brain center or module for generating a "theory of other minds" as proposed by Nick Humphrey and Simon Baron-Cohen? If so, where is this circuit and how and when did it evolve?

The solution to many of these riddles comes from an unlikely source.. the study of single neurons in the brains of monkeys. I suggest that the questions become less puzzling when you consider Giaccamo Rizzollati's recent discovery of "mirror neurons' in the ventral premotor area of monkeys. This cluster of neurons, I argue, holds the key to understanding many enigmatic aspects of human evolution. Rizzollati and Arbib have already pointed out the relevance of their discovery to language evolution . But I believe the significance of their findings for understanding other equally important aspects of human evolution has been largely overlooked. This, in my view, is the most important unreported "story" in the last decade.

THE EMERGENCE OF LANGUAGE

Unlike many other human traits such as humor, art, dancing or music the survival value of language is obvious — it helps us communicate our thoughts and intentions. But the question of how such an extraordinary ability might have actually evolved has puzzled biologists, psychologists and philosophers at least since the time of Charles Darwin. The problem is that the human vocal apparatus is vastly more sophisticated than that of any ape but without the correspondingly sophisticated language areas in the brain the vocal equipment alone would be useless. So how did these two mechanisms with so many sophisticated interlocking parts evolve in tandem? Following Darwin's lead I suggest that our vocal equipment and our remarkable ability to modulate voice evolved mainly for producing emotional calls and musical sounds during courtship ("croonin a toon."). Once that evolved then the brain — especially the left hemisphere — could evolve language.

But a bigger puzzle remains. Is language mediated by a sophisticated and highly specialized "language organ" that is unique to humans and emerged completely out of the blue as suggested by Chomsky? Or was there a more primitive gestural communication system already in place that provided a scaffolding for the emergence of vocal language?

Rizzolatti's discovery can help us solve this age-old puzzle. He recorded from the ventral premotor area of the frontal lobes of monkeys and found that certain cells will fire when a monkey performs a single, highly specific action with its hand: pulling, pushing, tugging, grasping, picking up and putting a peanut in the mouth etc. different neurons fire in response to different actions. One might be tempted to think that these are motor "command" neurons, making muscles do certain things; however, the astonishing truth is that any given mirror neuron will also fire when the monkey in question observes another monkey (or even the experimenter) performing the same action, e.g. tasting a peanut! With knowledge of these neurons, you have the basis for understanding a host of very enigmatic aspects of the human mind: "mind reading" empathy, imitation learning, and even the evolution of language. Anytime you watch someone else doing something (or even starting to do something), the corresponding mirror neuron might fire in your brain, thereby allowing you to "read" and understand another's intentions, and thus to develop a sophisticated "theory of other minds." (I suggest, also, that a loss of these mirror neurons may explain autism — a cruel disease that afflicts children. Without these neurons the child can no longer understand or empathize with other people emotionally and therefore completely withdraws from the world socially.)

Mirror neurons can also enable you to imitate the movements of others thereby setting the stage for the complex Lamarckian or cultural inheritance that characterizes our species and liberates us from the constraints of a purely gene based evolution. Moreover, as Rizzolati has noted, these neurons may also enable you to mime — and possibly understand — the lip and tongue movements of others which, in turn, could provide the opportunity for language to evolve. (This is why, when you stick your tongue out at a new born baby it will reciprocate! How ironic and poignant that this little gesture encapsulates a half a million years of primate brain evolution.) Once you have these two abilities in place the ability to read someone's intentions and the ability to mime their vocalizations then you have set in motion the evolution of language. You need no longer speak of a unique language organ and the problem doesn't seem quite so mysterious any more.

(Another important piece of the puzzle is Rizzolatti's observation that the ventral premotor area may be a homologue of the "Broca's area" — a brain center associated with the expressive and syntactic aspects of language in humans).

These arguments do not in any way negate the idea that there are specialized brain areas for language in humans. We are dealing, here, with the question of how such areas may have evolved, not whether they exist or not.

Mirror neurons were discovered in monkeys but how do we know they exist in the human brain? To find out we studied patients with a strange disorder called anosognosia. Most patients with a right hemisphere stroke have complete paralysis of the left side of their body and will complain about it, as expected. But about 5% of them will vehemently deny their paralysis even though they are mentally otherwise lucid and intelligent. This is the so called "denial" syndrome or anosognosia. To our amazement, we found that some of these patients not only denied their own paralysis, but also denied the paralysis of another patient whose inability to move his arm was clearly visible to them and to others. Denying ones one paralysis is odd enough but why would a patient deny another patient's paralysis? We suggest that this bizarre observation is best understood in terms of damage to Rizzolatti's mirror neurons. It's as if anytime you want to make a judgement about someone else's movements you have to run a VR (virtual reality) simulation of the corresponding movements in your own brain and without mirror neurons you cannot do this .

The second piece of evidence comes from studying brain waves (EEG) in humans. When people move their hands a brain wave called the MU wave gets blocked and disappears completely. Eric Altschuller, Jamie Pineda, and I suggested at the Society for Neurosciences in 1998 that this suppression was caused by Rizzolati's mirror neuron system. Consistent with this theory we found that such a suppression also occurs when a person watches someone else moving his hand but not if he watches a similar movement by an inanimate object. (We predict that children with autism should show suppression if they move their own hands but not if they watch some one else. Our lab now has preliminary hints from one highly functioning autistic child that this might be true (Social Neuroscience Abstracts 2000).

Please continue reading at http://www.edge.org/3rd_culture/ramachandran/ramachandran_p4.html.