Mirror-neuron activity can go awry in many ways, sometimes in full-blown neurological disorders but also, I suspect, in numerous, more subtle ways as well. For instance, I wonder whether a dissolution of interpersonal boundaries may also explain more exotic syndromes such as folie a deux, in which two people, such as Bush and Cheney, share each other’s madness. Romantic love is a minor form of folie a deux, a mutual delusional fantasy that often afflicts otherwise normal people. Another example is Munchausen syndrome by proxy, in which hypochondriasis (where every trifling symptom is experienced as a harbinger of fatal illness) is unconsciously projected onto another (the “proxy”)—often by a parent onto his or her child—instead of onto oneself.
Much more bizarre is the Couvade syndrome, in which men in Lamaze classes start developing pseudocyesis, or false signs of pregnancy. (Perhaps mirror-neuron activity results in the release of empathy hormones such as prolactin, which act on the brain and body to generate a phantom pregnancy.)
Even Freudian phenomena such as projection begin to make sense: You wish to deny your unpleasant emotions, but they are too salient to deny completely so you ascribe them to others; it’s the I-you confusion again. As we will see, this is not unlike a patient with somatoparaphrenia “projecting” her paralyzed arm to her mother. Lastly, there is Freudian countertransference, in which the psychoanalyst’s self starts fusing with the patient’s, which can sometimes land the psychoanalist in legal trouble if the patient is of the opposite sex.
Obviously, I am not claiming to have “explained” these syndromes; I am merely pointing out how they might fit into our overall scheme and how they may give us hints about the manner in which the normal brain constructs a sense of self.
AUTISM
In Chapter 5, I presented evidence that a paucity of mirror neurons, or the circuits they project to, may underlie autism. If mirror neurons do indeed play a role in self-representation, then one would predict that an autistic person, even a high-functioning one, could probably not introspect, could never feel self-esteem or self- deprecation—let alone experience self-pity or self-aggrandizement—or even know what these words mean. Nor could the child experience the embarrassment—and the blush—that accompanies the state of being self-conscious. Casual observations of autistic people suggest that all this might be true, but there have been no systematic experiments to determine the limits of their introspective abilities. For example, if I were to ask you what’s the difference between need and desire (you need toothpaste; you desire a woman or man), or between pride and arrogance, hubris and humility, or sadness and sorrow, you would typically think for a bit before being able to spell out the distinction. An autistic child may be incapable of these distinctions while still being capable of other abstract distinctions (such as “What’s the difference between a Democrat and a Republican, other than IQ?”).
Another subtle test might be to see whether a high-functioning autistic child (or adult) can understand a conspiratorial wink, which usually involves a three-way social interaction between you, the person you are winking at, and a third person—real or imaginary—in the vicinity. This requires representing one’s own as well as the other two people’s minds. If I give you a sly wink when telling a lie to someone else (who can’t see the wink), then I have an implied social contract with you: “I am letting you in on this—see how I am tricking that person?” A wink is also used when flirting with someone, unbeknownst to others in the vicinity, although I don’t know if this is universal to all cultures. (And, lastly, you wink to someone to whom you are saying something in jest as if to say, “You realize I am only are joking, right?”) I once asked the famous high-functioning autist and writer Temple Grandin whether she knew what winking meant. She told me that she understands winking intellectually but doesn’t ever do it and has no intuitive feel for it.
More directly relevant to the framework of the present chapter is the observation made by Leo Kanner (who first described autism) that autistic children often confuse the pronouns “me” and “you” in conversation. This shows a poor differentiation of ego boundaries and a failure of the self-other distinction which, as we have seen, depends partially on mirror neurons and associated frontal inhibitory circuitry.
THE FRONTAL LOBES AND THE INSULA
Earlier in this chapter, I suggested that apotemnophilia results from a mismatch between somatosensory cortices S1 and S2, on the one hand, and on the other the superior (and inferior) parietal lobules, the region where you normally construct a dynamic image of your body in space. But where exactly is the mismatch detected? Probably in the insula, which is buried in the temporal lobes. The posterior (back) half of this structure combines multiple sensory inputs—including pain—from internal organs, muscles, joints, and vestibular (sense of balance) organs in the ear to generate an unconscious sense of embodiment. Discrepancies between different inputs here produce vaguely articulated discomfort, as when your vestibular and visual senses are put in conflict on a ship and you feel queasy.
The posterior insula then relays to the front (anterior) part of the insula. The eminent neuroanatomist, Arthur D. (Bud) Craig, from the Barrow Neurological Institute in Phoenix, has suggested that the posterior insula registers only rudimentary unconscious sensations, which need to be “re-represented” in more sophisticated form in the anterior insula before your body image can be consciously experienced.
Craig’s “re-representations” are loosely similar to what I called “metarepresentations” in
So far in this book, I have said very little about the frontal lobes, which became especially well developed in hominins and must play an important role in our uniqueness. Technically the frontal lobes are comprised of the motor cortex as well as the bulk of the cortex in front of it—the prefrontal cortex. Each prefrontal lobe has three subdivisions: the ventromedial prefrontal (VMF), or bottom inner part; the dorsolateral (DLF), or upper outer part; and the dorsomedial (DMF), or upper inner part (see Figure Int.2, in the Introduction). (Because the colloquial term “frontal lobes” includes the prefrontal cortex as well, I use “F” in these abbreviations, not “P.”) Let’s consider some of the functions of these three prefrontal regions.
I invoked the VMF in Chapter 8 when discussing pleasurable aesthetic responses to beauty. The VMF also receives signals from the anterior insula to generate your conscious sense of being embodied. In conjunction with parts of the anterior cingulate cortex (ACC), it motivates “desire” to take action. For instance, the discrepancy in body image in apotemnophilia, picked up in the right anterior insula, would be relayed to the VMF and the anterior cingulate to motivate a conscious plan of action: “Go to Mexico and get the arm removed!” In parallel, the insula projects directly to the amygdala, which activates the autonomic fight-or-flight response via the hypothalamus. That would explain the heightened skin sweating (galvanic skin response, or GSR) that we saw in our patients with apotemnophilia.
Of course, all this is pure speculation; at this point we don’t even know whether my explanation of apotemnophilia is correct. Nonetheless, my hypothesis illustrates the style of reasoning needed to explain many brain disorders. Just brushing such disorders aside as being “mental” or “psychological” problems serves no purpose; such labeling neither illuminates normal function nor helps the patient.
Given their extensive connections with limbic structures, it is hardly surprising that the medial frontal lobes— the VMF and possibly the DMF—are also involved in setting up the hierarchy of values that govern your ethics and
