Mirror Neurons, the Mind-Body Problem, and The Limits of Neurology

The third of four neuroscience posts today/tomorrow, this one comes to us from the New […]

David Zahl / 3.8.11

The third of four neuroscience posts today/tomorrow, this one comes to us from the New York Review of Books, more precisely, Colin McGinn’s thoughtful review of V.S. Ramachandran’s new book, The Tell-Tale Brain: A Neuroscientist’s Quest for What Makes Us Human. A bit more technical than the previous two installments, this one may have you glazing over with its talk of ‘mirror neurons’… But stick with it, as the questions at the bottom are the same, i.e. What makes us human? Why do we act the way we do? Do we have free will? Is there more to the mind than the brain (and vice versa)? Are we primarily rational or emotional creatures? Or is that a false dichtomy? To what extent do universal ‘laws’ rule our consciousness? What role does nature play vs. nurture? And where are the limits of neurology? McGinn rightly pinpoints the inflated anthropology running underneath – the word ‘reductionism’ is a frequent one – making it a fitting counterpoint to David Livingston Smith’s point of view. Enjoy, ht MB:

The mirror neurons that have been identified in the brain serve as the mechanism of imitation, [Ramachandan] suggests, in virtue of their ability to react or “fire” sympathetically, and thus affect consciousness, when you are watching someone else do something: some of the same neurons fire both when you observe the performance of an action and when you actually perform that action. This is held to show that the brain automatically produces a representation of someone else’s “point of view”—it runs by means of mirroring neurons an internal simulation of the other’s intended action.

The mirror neurons act like sympathetic movements that can occur when watching someone else perform a difficult task—as when your arm swings slightly when you watch someone hit a ball with a bat. For Ramachandran this specific neural circuitry provides the key to understanding the growth of culture; indeed, the mirror neurons are held to permit the evolution of language, by enabling imitative utterance. According to him, we need special inhibitory mechanisms in order to keep our mirror neurons under control—or else we would be in danger of doing everything we see and losing our sense of personal identity. We are, in effect, constantly impersonating others at a subconscious level, as our hyperactive mirror neurons issue their sympathetic reactions. 

Ramachandran next ventures into the evolution of our aesthetic sense. He seeks a science of art. Enunciating nine “artistic universals,” he propounds what he allows is a “reductionist” view of art, attempting to provide brain-based laws of aesthetic response. Peacocks, bees, and bowerbirds possess rudimentary aesthetic responses, he suggests, and we are not so different. Thus we respond well to “grouping” and “peak shift”: we like similarly colored things to go together, and we are entranced by certain kinds of exaggeration of ordinary reality (as with caricatures) or other unrealistic images in art (like the Venus of Willendorf, as cited by Nigel Spivey in How Art Made the World). These biases result from our evolutionary ancestry as arboreal survivors—seeing lions through leaves and so on. Our taste for abstract art is compared to the propensity of gulls to be attracted to anything with a big red dot on it, since mother gulls have such a dot on their beak: “I suggest this is exactly what human art connoisseurs are doing when they look at or purchase abstract works of art; they are behaving exactly like the gull chicks.”

For instance, mirror neurons are clearly an interesting discovery, but are they really the explanation of empathy and imitation?* Isn’t much more involved? Does an expert impersonator simply have more (or more active) mirror neurons than the average human? What about the ability to analyze an observed action, not merely repeat it? Where does flexibility in deepness of imitation come from (it cannot be those reflexive mirror neurons)? Imitation, moreover, comes in many forms, of different degrees of sophistication, and we cannot assimilate the trained mime to the baby’s reflex of poking out her tongue at the sight of her mother doing the same.

Ramachandran acknowledges no limit to neural reductionism, but there is a very big issue here that he slides over: the mind–body problem. His suggestion that by identifying the part of the brain involved in voluntary decision we turn a philosophical problem into a neurological one could only be made by someone who does not know what philosophical problem is in question—to put it briefly, whether or not determinism conceptually rules out freedom of the will. That question cannot be answered by pointing to one case of brain damage or another. Learning about the parts of the brain responsible for free choice will not tell us how to analyze the concept of freedom or whether it is possible to be free in a deterministic world. These are conceptual questions, not questions about the form of the neural machinery that underlies choice. His book has all the charm of an enthusiast’s tract—along with the inevitable omissions, distortions, and exaggerations.

Ramachandran operates with a rather rosy view of the human species—our darker side does not enter his calculations. What about our capacity for violence, domination, conformity (those mirror neurons!), deception, self-delusion, clumsiness, depression, cruelty, and so on? Where is the neural basis for those traits? Or are they somehow not part of our cerebral wiring? Isn’t the human brain equally an inferior brain?

Why is neurology so fascinating? It is more fascinating than the physiology of the body—what organs perform what functions and how. I think it is because we feel the brain to be fundamentally alien in relation to the operations of mind—as we do not feel the organs of the body to be alien in relation to the actions of the body. It is precisely because we do not experience ourselves as reducible to our brain that it is so startling to discover that our mind depends so intimately on our brain. It is like finding that cheese depends on chalk—that soul depends on matter. This de facto dependence gives us a vertiginous shiver, a kind of existential spasm: How can the human mind—consciousness, the self, free will, emotion, and all the rest—completely depend on a bulbous and ugly assemblage of squishy wet parts? What has the spiking of neurons got to do with me?

Neurology is gripping in proportion as it is foreign. It has all the fascination of a horror story—the Jekyll of the mind bound for life to the Hyde of the brain. All those exotic Latin names for the brain’s parts echo the strangeness of our predicament as brain-based conscious beings: the language of the brain is not the language of the mind, and only a shaky translation manual links the two. There is something uncanny and creepy about the way the brain intrudes on the mind, as if the mind has been infiltrated by an alien life form. We are thus perpetually startled by our evident fusion with the brain; as a result, neurology is never boring. And this is true in spite of the fact that the science of the brain has not progressed much beyond the most elementary descriptive stages.