another person’s pain may be empathic, neutral, or even counterempathic.
In the previous chapter we explored the circuitry of the brain that underlies our tendencies to violence; now let’s see the parts that underlie our better angels. The search for empathy in the human brain has confirmed that vicarious feelings are dimmed or amplified by the rest of the empathizer’s beliefs. Claus Lamm, Daniel Batson, and Jean Decety had participants take the perspective of a (fictitious) patient with ringing in his ears while he got “treated” with an experimental cure consisting of blasts of noise over headphones, which made the patient visibly wince.27 The pattern of activity in the participants’ brains as they empathized with the patient overlapped with the pattern that resulted when they themselves heard the noise. One of the active areas was a part of the insula, the island of cortex that, as we have seen, represents literal and metaphorical gut feelings (see figure 8–3). Another was the amygdala, the almond-shaped organ that responds to fearful and distressing stimuli (see figure 8–2). A third was the anterior medial cingulate cortex (see figure 8–4), a strip of cortex on the inward-facing wall of the cerebral hemisphere that is involved in the motivational aspect of pain—not the literal stinging sensation, but the strong desire to turn it off. (Studies of vicarious pain generally don’t show activation in the parts of the brain that register the actual bodily sensation; that would be closer to a hallucination than to empathy.) The participants were never put in the kind of situation that evokes counterempathy, like competition or revenge, but their reactions were pushed around by their cognitive construal of the situation. If they had been told that the treatment worked, so the patient’s pain had been worthwhile, their brains’ vicarious and distressed responses were damped down.
The overall picture that has emerged from the study of the compassionate brain is that there is no empathy center with empathy neurons, but complex patterns of activation and modulation that depend on perceivers’ interpretation of the straits of another person and the nature of their relationship with the person. A general atlas of empathy might look more or less as follows.28 The temporoparietal junction and nearby sulcus (groove) in the superior temporal lobe assess another person’s physical and mental state. The dorsolateral prefrontal cortex and the nearby frontal pole (the tip of the frontal lobe) compute the specifics of the situation and one’s overall goals in it. The orbital and ventromedial cortex integrate the results of these computations and modulate the responses of the evolutionarily older, more emotional parts of the brain. The amygdala responds to fearful and distressing stimuli, in conjunction with interpretations from the nearby temporal pole (the tip of the temporal lobe). The insula registers disgust, anger, and vicarious pain. The cingulate cortex helps to switch control among brain systems in response to urgent signals, such as those sent by circuits that are calling for incompatible responses, or those that register physical or emotional pain. And unfortunately for the mirror-neuron theory, the areas of the brain richest in mirror neurons, such as parts of the frontal lobe that plan motor movements (the rearmost portions above the Sylvian fissure) and the parts of the parietal lobes that register the body sense, are mostly uninvolved, except for the parts of the parietal lobes that keep track of whose body is where.
In fact, the brain tissue that is closest to empathy in the sense of compassion is neither a patch of cortex nor a subcortical organ but a system of hormonal plumbing. Oxytocin is a small molecule produced by the hypothalamus which acts on the emotional systems of the brain, including the amygdala and striatum, and which is released by the pituitary gland into the bloodstream, where it can affect the rest of the body.29 Its original evolutionary function was to turn on the components of motherhood, including giving birth, nursing, and nurturing the young. But the ability of the hormone to reduce the fear of closeness to other creatures lent itself over the course of evolutionary history to being co-opted to supporting other forms of affiliation. They include sexual arousal, heterosexual bonding in monogamous species, marital and companionate love, and sympathy and trust among nonrelatives. For these reasons, oxytocin is sometimes called the cuddle hormone. The reuse of the hormone in so many forms of human closeness supports a suggestion by Batson that maternal care is the evolutionary precursor of other forms of human sympathy. 30
In