I am not trained in science, which means that I know very little about scientific practice and theory-building. Once in a while I realize, however, that my training in philosophy helps me question some highly mystifying ideas that pop up within the field of psychology and neuroscience. Today I read about something that sounds very evocative and very cutting-edge: mirror neurons! (How on earth....? Well, I was looking at a review of a Virno book and he has apparently utilized the concept/theory in question). For what reason have scientists started talking about mirror neurons? Scientists want to grasp the ability of humans to act and to understand other people and their actions. Our abilities as linguistic beings belong here, too. How are these "abilities" to be explained? It is taken for granted that science could solve these "mysteries". In other words: scientists think that we can talk about "an ability" to understand another and that this ability could be explained empirically, relating it to some other thing/mechanism/function that shows by virtue of what we have that seemingly odd ability.
A monkey performs "a motor act". A specific class of neuron are fired. A monkey watches another individual perform the same or similar act - the same class of neurons is discharged. A hand is interacting with a specific object (a banana, not an apple). When the monkey sees some objects, the same class of neurons are not fired. This is, supposedly, the result of empirical tests (technicalities here). Empirical tests have also indicated mirror neurons in human brains.
From Scholarpedia: "What might be the functional role of the mirror neuron system? A series of hypotheses such as action understanding, imitation, intention understanding, and empathy have been put forward to explain the functional role of the mirror neurons. In addition to these, it has also been suggested that the mirror neuron system represents the basic neural mechanism from which language evolved. The question, however, of what is the function of the mirror neuron system is probably an ill posed question. Mirror neurons do not have a unique functional role. Their properties indicate, rather, that they represent a mechanism that maps the pictorial description of actions carried out in the higher order visual areas onto their motor counterpart. This matching mechanism may underlie a variety of functions."
How come we understand something as an action, and that we are not simply presented with this or that visual image? This question lies at the ground of the mirror neuron discussion. The involvement of the motor system of our brains is necessary for what it is to understand actions and to observe the similarity between events and movements. "Thus, the activation of the mirror circuit is essential to provide the observer with a real experiential comprehension of the observed action." (Scholarpedia) The fact that our brains function in this vein displays "a rudimentary form of social interaction" (ibid).
Experiments and theoretical models have suggested mirror neurons to explain - or at least to be involved in, provide "the functional mechanism" of - our grasp of intional behavior. "In this experiment volunteers were presented with hand actions without a context and hand actions executed in contexts that allowed them to understand the intention of the action agent. The main result of the study was the demonstration that actions embedded in contexts yielded selective activation of the mirror neuron system. This indicates that mirror areas, in addition to action understanding, also mediate the understanding of others’ intention (Iacoboni et al. 2005)." (ibid) I take all this to imply a view of actions as existing "in" the world, as natural entities. The mirror neuron scientists talk about actions at the level of "observation" as comprising of visual data worming its way into our brains which, hence, are argued to be equipped with the ability to make distinctions between what is an instance of the same action, and what is an instance of a different action.
Gallese on the findings of the macaque experiments: "Action observation causes in the observer the automatic activation of the same neural mechanism triggered by action execution." (ibid) Gallese is even talking about "a direct form of action understanding" and the ground for it provided by these empirical findings. "The same functional logic that presides over self-modeling is employed also to model the behavior of others: to perceive an action is equivalent to internally simulating it. This enables the observer to use her/his own resources to experientially penetrate the world of the other by means of a direct, automatic, and unconscious process of simulation." (ibid) What is simulation? It is, according to Gallese, "an automatic, unconscious, and pre-reflexive functional mechanism, whose function is the modeling of objects, agents, and events." (ibid) The triggering of mirror neurons thus has an epistemic content, summed up by Galles as "representational". And do note that we are still talking about brains, not human beings who react, think and feel!
In the end, we have to remember the logic implied here: mirror neurons are triggered by visual stimuli. I understand Gallese as saying that "visual stimuli" becomes "an action performed by an observer" by means of simulation triggered by mirror neurons.
Researchers have also tried to show that a specific set of neurons are fired when we experience something emotional and when we experience the same emotion in the facial expressions of others. When you see a spider crawl up someone's leg, you feel a creepy sensation because your mirror neurons are firing. In the words of Vittorio Gallese, who attempts to resist the solipsism nourished by cognitive science: "By means of intentional attunement, “the others” are much more than being different representational systems; they become persons, like us." (source) Later on, he explains his understanding of emotions: "Emotions constitute one of the earliest ways available to the individual to acquire knowledge about its situation, thus enabling to reorganize this knowledge on the basis of the outcome of the relations entertained with others." (ibid) The perspective employed here is extremely epistemological: emotions have to do with knowledge about people and what they will do next. "The sensory-motor system appears to support the reconstruction of what it would feel like to be in a particular emotion, by means of simulation of the related body state." In philosophy there is the classical analogy argument: I am able to know what you feel by drawing an analogy to myself in the same state. But here there is no need for an "intellectual" analogy; the analogy is inscribed in our sensory-motor systems. The gist of the argument is that mirror neurons make us experience "the same bodily state" as the other when we "observe" a specific facial expression.
The theory posed by Gallese is hard to understand without the background of questions in philosophy. "Such body-related experiential knowledge enables us to directly understand some of the actions performed by others, and to decode the emotions and sensations they experience." What is it that we understand when we understand the actions that other people perform? How can be know things about the mind of others? Traditionally, philosophy of action have dealt with these question by making a distinction between actions and events. They have proceeded by elaborating "action" as consisting of beliefs and desires. Traditional philosophy of action shares with Gallese the epistemological perspective that actions can be converted into a certain set of information about the world, albeit this information being combined with a specific interest (desire). The question about what constitutes "the same action" occupied early philosophy of action (Anscombe et cetera) but now that question has waned, at least to some extent. But for Gallese it becomes a pertinent one. He talks about actions as if they are natural classes existing in the world. "The event of gripping a banana".
It's hard to embark on the project of criticism with regard to "mirror neurons". Everything about it seems wrong and confused. The most striking thing about it is, in my opinion, the way perception is represented here as a neutral process of data somehow digested by our brains. "Successful perception requires the capacity of predicting upcoming sensory events." (ibid) A sad, angry or ironical face is here conceived as a specific (temporally fixated) set of data - a physical structure. Not only is that a totally hopeless approach to "facial expressions", it is also a misconceived picture of what it is to see and hear. We are not beings who "observe" the world in general, things being triggered within us. Take Anscombe's example (I don't like what she makes of it, but still.). I see a scary face in a window. It makes me jump. You see my strange demeanour. "What is it?" you say. I shudder, and explain what I just saw. Gallese could not say a word about this example, and this shows how impossible his view is. He talks about "facial expressions" and "actions" but none of it has to do with real interaction between people, even though that is somehow the focus of his interest. Was my scared expression simulated in your sensory-motor system? But for what do we need that hypothesis? What is it to explain? Gallese seems to pose a mystery, a gap, between "my actions" and "your actions", "my emotions" and "your emotions". But when you see me jump and when you wonder what has gotten into me, you are not seeking information. You react to me. That is what Gallese does not at all apprehend. For him, and for many philosophers as well, our understanding of each other has to be mediated by something, be it analogies or representations or belief&desires or mirror neurons. It is precisely that presupposition I find to be - excuse me - silly.
And now I have not said a word about the ways in which Gallese's hypothesis involves an idea about "a small man within our brain". But I think it does. "Our seemingly effortless capacity to conceive of the acting bodies inhabiting our social world as goal-oriented persons like us depends on the constitution of a “we-centric” shared meaningful interpersonal space." Dear Gallese: it is very strange to talk about "acting bodies"? When I perceive Mr Gallese in the midst of heated debate on mirror neurons or Mr Gallese sitting in his study, there is no level of primordial seeing that constitutes "the acting body" which has to be combined with some more stuff in order for me to see Mr Gallese argue or work in his study. (Questions might arise, but they are rarely related to our brains. "Is mister Gallese asleep? Or is he just thinking really hard about mirror neurons?" My brain will not fix the certainty or the uncertainty that might come into question. There is simply no general concept of certainty at play here.
An article from New York Times discusses the "cutting-edge" of mirror neurons. Laugh - or cry. I nudge my eyes, but yes. Over to Patricia Greenfield, U.C.L.A.: "Until now, scholars have treated culture as fundamentally separate from biology, she said. 'But now we see that mirror neurons absorb culture directly, with each generation teaching the next by social sharing, imitation and observation.'" (source) So the mirror neuron hypothesis/findings fit in neatly with evolutionary biology.
"Social emotions like guilt, shame, pride, embarrassment, disgust and lust are based on a uniquely human mirror neuron system found in a part of the brain called the insula, Dr. Keysers said. In a study not yet published, he found that when people watched a hand go forward to caress someone and then saw another hand push it away rudely, the insula registered the social pain of rejection. Humiliation appears to be mapped in the brain by the same mechanisms that encode real physical pain, he said." (ibid) I mean, seriously.
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