Monday, April 30, 2007

The Myth of Mirror Neurons?

In an article in a special issue of Slate devoted to the brain (well worth checking over...I'll give some links to articles in the Slate issue in subsequent posts), Gopnik argues that excitement over the discovery of mirror neurons in our brains (the subject of a number of blog posts and my lecture posted earlier...) is generating a new scientific myth. Like a traditional myth, it captures intuitions about the human condition through vivid metaphors. Some clips:
It didn't take long for scientists and science writers to speculate that mirror neurons might serve as the physiological basis for a wide range of social behaviors, from altruism to art appreciation. Headlines like "Cells That Read Minds" or "How Brain's 'Mirrors' Aid Our Social Understanding" tapped into our intuitions about connectedness. Maybe this cell, with its mellifluous name, gives us our special capacity to understand one another—to care, to learn, and to communicate. Could mirror neurons be responsible for human language, culture, empathy, and morality?.

The evidence for individual mirror neurons comes entirely from studies of macaque monkeys. That's because you can't find these cells without inserting electrodes directly (though painlessly) into individual neurons in the brains of living animals. These studies haven't been done with chimpanzees, let alone humans.

The trouble is that macaque monkeys don't have language, they don't have culture, and they don't understand other animals' minds. In fact, careful experiments show that they don't even systematically imitate the actions of other monkeys—and they certainly don't imitate in the prolific way that the youngest human children do. Even chimpanzees, who are much more cognitively sophisticated than macaques, show only very limited abilities in these areas. The fact that macaques have mirror neurons means that these cells can't by themselves explain our social behavior.


  1. I'm surprised to read the statement 'The trouble is that macaque monkeys don't have language, they don't have culture, and they don't understand other animals' minds.' I think this statement is probably incorrect.

    There is a fairly classical example of the Macaques on Koshima islet. One of the Macaques invented the technique of washing sweet potatoes in the river before eating them. The behaviour quickly spread, firstly horizontally amongst the monkey's peer group, then vertically amongst the rest of the group.

  2. You're right. She should not have said 'they don't have culture' de Waal's definition of culture they certainly do. However, that does not have to imply that they understand other animal's minds.

    I guess Gopnik's main point is that the similar data obtained on monkey and human brains is sometimes offered as an explanation for human capabilities that monkey's don't have. Many proponents of generous interpretations of mirror neuron data do make the caveat that the data suggest a rudimentary foundation on which more advanced capabilities are built.

  3. I agree with the idea that the role of mirror neurons is probably insightful for explaining some of the basic aspects of social life but also has led to some theoretical shortcomings. For instance, some authors are using the MNs to sustain the thesis of simulation theory in the so called 'theory of mind' polemic. IMHO, it is time to apprehend such complex phenomenons as theory of mind, mutual modeling and empathy in a more sophisticated way that integrates different macro models (theory theory + simulation theory...) and micro-level data (mirror neurons).

    Sometimes the never ending polemics between extreme positions in research traditions despair efficiency and give birth to more sterile debates than prolific and useful contributions.

  4. Our mirror neurons don't have to look different from monkey neurons to deserve being cast in a lead role for what distinguishes human brains. 1) It's not what you have, but what you do with it (e.g. A,C,G & T in the chromosomes), 2) Initially subtle and hard-to-discern differences nevertheless may be crucial (e.g. A,C,G & T in the chromosomes) & 3) explaining is subjective, selective and depends as much on the vehicle and the audience as it does on objective "ground truths" (e.g. it's hard to center a love story around a transcription factor, even though some fans will never forgive you).