Marco Iacoboni, Mirroring People (2008)

This important volume might have been titled The Feeling of What Happens (To Other People), but the neurology community would have immediately recognized a title borrowed from a crosstown Los Angeles rival, Antonio Damassio's The Feeling of What Happens (1999). In both Iacoboni and Damassio, you have two preeminent neuroscientists on the leading edge of brain research writing accessible books about their research for the public. Both connect their brain research to a philosophy of the mind that we used to study before science supplanted philosophy and unified our understanding of the mind and brain. In Iacoboni's case, the philosophical tradition is rooted in the phenomenology of Maurice Merleau-Ponty, with a tip to William James. In Damassio's case, the spirit of James is clearly acknowledged, but Damassio finds his roots in Spinoza's rejection of Descartes' dualism of mind and body, as explained in Descartes Error (1994) and Looking for Spinoza (2004). There is something in common between these two besides William James. That the mind is an extension of the body is a view shared by both Spinoza and phenomenologists, and they share the view that Descartes was wrong or at least problematic.

Damassio's attention is directed at consciousness, feelings, emotions and cognition, a breathtaking subject-matter that many believe will ultimately be understood and explained through neurological research. Iacoboni's research fits within the landscape of this huge topic, but it is more focused, describing the research begun by colleagues in Parma, Italy in the 1980s on macaque monkeys that resulted in the discovery of mirror neurons. Interestingly, the word 'consciousness' is not mentioned once in Mirroring People, although Iacoboni's discussion of one's sense of self and sense of others does relate to consciousness. In contrast, Damassio acknowledges the role of mirror neurons in cognitive processes related to emotion and feelings.

So what are these mirror neurons, what are their significance, and what do they mean for our history of ideas? Mirror neurons are a type of brain cell that fire in response to a perceived action of another. It just so happens that the same neuron fires in response to the self undertaking the same action. They are found in several parts of the brain, but importantly they are found in the premotor cortex -- a part of the neocortex responsible for planning and executing actions. The same cells fire in response to perception and action. This is true for humans and other primates.

Research indicates that mirror neurons are important to ascribing intentions to others even when they have not declared their intention. When we see or hear an action undertaken by an "other," we understand their intentions by simulating (or imitating) them in our brain. Different cells fire with respect to a different action (revealing a different perceived intention) on the same object. It is as if you could say, I know what you are thinking, or, I feel your pain. Mirror neurons are clearly important to cognitive and emotional states critical to our understanding of and relationships with others, such as empathy and mental conditions such as autism, as well as our own actions. The phrase "No man is an island" takes on greater meaning because of the discovery of mirron neurons. Interdependence is a biological fact. Subjectivity is said to be a characteristic of the individual mind, but for Iacoboni, intersubjectivity is something we ought to be seriously looking at.

Our understanding of mirror neurons is an important key to understanding and resolving the age-old debate as to whether nature or nurture is responsible for our behavior. It is clearly both, and the research undertaken by Iacoboni and others at UCLA seems to confirm this. Mirror neurons are present at birth, and we know this because the infant begins to imitate its parents and others from the beginning. The mirror neurons begin to fire for the first time and are continuously developed through interaction with others and our environment. This process appears to continue through our lives as we grow to become part of group, community or society, as mirror neuron research shows that these neurons fire more strongly when we hear or see something that is associated with the family, group, community or society that we affiliate with and interact most closely. Mirror neuron research strongly supports Evo Devo, evolutionary developmental biology. For example, in the case of humans. our gestation period in the womb is not long enough for the complete development of the brain, which continues to grow in the post-natal stage. If this were not the case, our head would be too large to pass through the brith canal. Human evolution has tied our survival to coming into the world in a state of helplessness, and only through post-natal development of the brain is our species' chances for survival enhanced. Strikingly, this development occurs almost immediately because of personal or social interaction with parents and others in the immediate family or community. Christine Kenneally's survey of language research, The First Word, reviewed below, demonstrates that language development fits this model as well.

So is our identity defined entirely by those around us, or is there a unique "self?" Self and other are "inextricably blended," says Iacoboni. The sense of self follows the sense of "us," which is the first "sense" of awareness an infant has immediately following its birth as a result of mother infant interactions. We are social animals first. The human's sense of self emerges in time. Interestingly, mirror neuron research has established that these neurons fire more strongly when we are perceiving ourselves as opposed to perceiving an other. Biologically, this might explain why humans view themselves more as independent individuals, rather than interdependent members of the same species.

Mirror neuron research, opines Iacoboni, suggests that the individual in western social and political philosophy is not as unique as we think, and further indicates that our western concept of free will might have to be revised. "Mirror neurons in our brains produce automatic imitative influences of which we are often unaware and that limit our autonomy by means of powerful social influences. We humans are social animals, yet our sociality makes us social agents with limited autonomy." This sounds threatening to the value system underlying western social, economic and political organization, but Iacoboni does not try to develop or elaborate on this thought any further. In contrast, Damassio's synthesis of the mind and body has its roots in Spinoza, who is probably more responsible for our western political system than any other philosopher of the Enlightenment. And for Spinoza, who rejected the separation of the physicality of emotions from the rational operations of the mind, free will found its expression in human choice. Iacoboni does not say that humans are without choice; he writes only in terms of "limited autonomy."

OK, so our choices are influenced, perhaps powerfully, by our social environment. But Iacoboni appears to suggest that if humans had wider, less insular social interaction and presumably more choices in belief systems to identify with, that we might come to appreciate how interdependent we are. He writes, "[T]rue cross-cultural encounters are actually made impossible by the influence of massive belief systems --- religious and political -- that deny continuously the fundamental neurobiology that links us together." There is not one monolithic belief system that controls us or renders free will a total illusion. Iacoboni refers to "belief systems" --- plural --- and, not surprisingly, there is conflict in these belief systems. Spinoza's life story is a story of choice among competing belief systems --- a true cross-cultural encounter that was not made impossible by the influence of a massive belief system. His life was an exercise of free will. And if we revise our notion of free will (which implicitly, if not explicitly recognizes that our choices are not free of all influence), what will we gain in terms of insight?

I see a larger volume on the human mind and mirror neurons in the future: a volume that more completely integrates the role of mirror neurons with the biological and psychological and emotional operations of the mind and body, discusses consciousness and memory, and the evolution and development of the brain. Iacoboni only briefly introduces the role of the limbic system in the brain that allows us to feel emotions, but he does not discuss the relationship of the mirror neurons in the brain to the central nervous system, nor does he explore the evolution of the brain (or mirror neurons for that matter), which is more fully explored by Damassio and also by Steven Rose in The Future of the Brain. These are not shortcomings of this important summary on the discovery of and subsequent research about the role of mirror neurons. More research will be needed before the next volume is written.