Empathy and the brain
© 2008 Gwen Dewar, Ph.D., all rights reserved
Human empathy depends on the ability to share the emotions of others—to “feel” what other people feel.
It is regarded by many people as the foundation of moral behavior.
But to some, the concept seems rather airy-fairy. What does it mean to say “I feel your pain”? Isn’t that just a fanciful flight of the imagination?
Well, not really.
For one thing, it turns out nonhuman animals—-even rodents-—show evidence of empathy.
For another, it appears that empathy has a neurological basis.
The same brain regions that process our first-hand experiences of pain are also activated when we observe other people in pain.
Moreover, when we observe the emotional signals of others, we recruit brain regions associated with theory of mind, the mechanism that permits us to take the perspective of another person (Schulte-Rüther et al 2007).
This theory of mind mechanism-—along with the ability to keep our own emotional reactions under control-—may be of crucial importance for showing empathic concern, or sympathy.
A person who lacked theory of mind or the ability to self-regulate emotions might focus solely on her own emotional reactions to another person’s plight. She might respond aversively to the victim, or--absorbed by her own emotional agitation--she might even become aggressive.
Empathy, then, involves a package of abilities. Here’s a quick guide to the biology of empathy, including information about the development of empathy in children.
Empathy among nonhuman animals
In one experiment, 15 rhesus monkeys were trained to get food by pulling chains. Monkeys quickly learned that one chain delivered twice as much food than the other. But then the rules changed. If a monkey pulled the chain associated with the bigger reward, another “bystander” monkey received an electric shock.
After seeing their conspecific get a shock, 10 of the monkeys switched their preferences to the chain associated with the lesser food reward. Two other monkeys stopped pulling either chain—preferring to starve rather than see another monkey in pain (Masserman et al 1964).
Mice, too, respond to the display of pain by their companions. Researchers at McGill University put pairs of mice together and injected one or both of them with a substance that induces mild stomach ache.
Mice reacted to the pain by wriggling and stretching their legs. But the intensity of the reaction depended on social cues. Mice wriggled and stretched more when their companions were also in pain (Langford 2006).
Moreover, mice exposed to the sight of a suffering cage mate were quicker to back away from an unpleasant heat source—suggesting that witnessing their companion’s discomfort made mice more sensitive to their own pain.
Empathy in children
So there is nothing particularly human about finding the painful experiences of others unpleasant.
But why is “second-hand” pain unpleasant or upsetting?
New research by neuroscientist Jean Decety suggests a fascinating neurological link between our own, first-hand experience of pain and our perception of pain in other people.
When typically developing kids (aged 7 to 12 years) were presented with images of people getting hurt, the kids experienced more activity in the same neural circuits that process first-hand experiences of pain (Decety et al 2008a).
This automatic response--termed “mirroring”—has also been documented in adults (Jackson et al 2006). The phenomenon may reflect the activation of mirror neurons, nerve cells that fire both when a person performs an action and he sees that action being performed by others.
To date, researchers have identified specific neurons involved in the mirroring of hand movements (Rizzolatti and Craighero 2004). No one yet has isolated specific mirror neurons for pain or emotion.
More than mirrors
Mirror neurons may explain how we can experience “second-hand” pain or emotion.
But to respond with empathic concern, we need other information, too.
We need to understand the perspectives of other people.
We also need to overcome our own negative reactions to the display of another person’s pain or distress.
Brain-imaging research seems to confirm this link between theory of mind and empathy. For instance, when people have been asked to evaluate the emotional facial expressions of others, they showed activation in the brain regions associated with theory of mind tasks (Schulte-Rüther et al 2007).
And theory of mind is probably important in other ways. For instance, Jean Decety and his colleagues have investigated how the brain distinguishes between the victims of accidents and victims of aggression.
The neural basis of morality?
To better understand how theory of mind contributes to the perception of “second hand” pain, Decety’s team showed kids two sets of images. One set depicted people experiencing painful accidents. The other set showed people who were being victimized by aggressors (Decety et al 2008a).
In both scenarios, functional magnetic resonance imaging (fMRI) revealed that merely looking at images activated brain regions associated with the first-hand experience of pain.
But when kids watched images of one person deliberately inflicting pain on another person, additional brain regions (in the orbital medial frontal cortex and the paracingulate cortex) were activated.
Brain imaging research and studies of brain-damaged patients suggest that these regions are associated with social interaction, emotional self-control, and moral reasoning (Blair 2007; Sturm et al 2006).
Were the additional brain regions activated because the kids were engaged in social and moral thinking? It seems very plausible.
The activation wasn’t caused by the mere presence of multiple people in the images, because researchers controlled for that.
And, when kids were debriefed at the end of the experiment, most of them commented on the unfairness with which the victims had been treated.
Empathy and the brain: When kids are cruel
The study mentioned above measured the responses of normally-developing kids. What about kids who show a cruel streak?
Decety’s group conducted a similar fMRI study on teenage boys with conduct disorder, or CD.
This disorder is a serious psychiatric condition linked with behaviors like physical aggression, manipulative lying, sexual assault, cruelty to animals, vandalism, and bullying. It’s also a precursor to antisocial personality disorder in adulthood (Lahey et al 2005).
Researchers screened boys (aged 16-18) for CD, and showed them the same types of images of accidents and assaults mentioned above.
The results were very interesting.
I feel your pain…and it makes me lash out
In some respects, the boys with CD responded like boys in the control group.
In particular, the mirror neuron system for pain was activated in both groups.
But there were dramatic differences.
First, the boys with conduct disorder experienced less activation in brain regions associated with self-regulation, theory of mind, and moral reasoning.
Second, the boys with CD actually exhibited a stronger “mirror” response to accidentally-caused pain.
And, unlike controls, the boys with conduct disorder experienced strong, bilateral activation in the amygdala and striatum.
What does this mean? It’s not clear. The amygdala processes emotion. And the striatum is activated by strong stimuli—both pleasurable and aversive.
So there are at least two possibilities.
The aggressive boys might have gotten a pleasurable “kick” out of viewing the pain of others.
But given that their own pain centers were strongly activated, it’s also possible that observing second-hand pain triggered negative emotions—emotions that make the boys behave more aggressively.
As Decety and his colleagues point out, negative emotions—particularly in people with poor emotional control—can cause agitation and outbursts of aggression (Berkowitz 2003). This effect may be magnified in kids who have trouble distinguishing their own first-hand pain from the pain of others.
Decety and colleagues speculate that boys with conduct disorder may experience high levels of agitation or distress when they experience second-hand pain. When this distress is combined with poor self-regulation of emotion, they lash out.
But whether second-hand pain makes aggressive kids feel good or irritable, one thing seems pretty certain:
The brains of boys with conduct disorder responded more intensely to images of other people experiencing pain.
And this intensity was linked with the boys’ aggressive tendencies. The more strongly a boy’s brain responded to second-hand pain, the more highly he scored on measures of daring and sadism.
Can empathy be taught?
Animal studies and brain scan research might make us wonder if feeling empathy is a purely automatic process.
But, as noted above, empathy is really a package of abilities, and there is evidence that empathy and empathic concern can be shaped by experience.
For more information, see this article on the
importance of fostering empathy
pratical tips for fostering empathy in kids.
References: Empathy and the brain
Blair RJR. 2007. The amygdale and ventromedial prefrontal cortex in morality and psychopathology. Trends in Cognitive Sciences 11: 387-392.
Decety J, Michalska K, and Akitsuki Y. 2008a. Who caused the pain? An fMRI investigation of empathy and intentionality in children. 46(11):2607-14
Decety J, Michalska K, Akitsuki Y and Lahey BB. 2008b. Atypical Empathetic Responses in Adolescents with Aggressive Conduct Disorder: A functional MRI Investigation. Biological Psychology. In press.
Jackson PL, Brunet E, Meltzoff AN, and Decety J. 2006. Empathy examined through the neural mechanisms involved in imaging how I feel versus how you feel pain: An event-related fMRI study. Neuropsychologia 44: 752-761.
Langford DJ, Crager SE, Shehzad Z, Smith SB, Sotocinal SG, Levenstadt JS, Chanda ML, Levitin DJ, and Mogil JS. 2006. Social Modulation of Pain as Evidence for Empathy in Mice. Science. 312(5782):1967-70.
Masserman JH. Wechkin S, and Terris W. 1964. “Altruistic” behavior in rhesus monkeys. American Journal of Psychiatry 121: 584-585.
Rizzolatti G. and Craighero L. 2004. The mirror-neuron system. Annual Review of Neuroscience 27: 169-92.
Schulte-Rüther M, Markowitsch HJ, Fink GR, and Piefke M. 2007.Mirror neuron and theory of mind mechanisms involved in face-to-face interactions: a functional magnetic resonance imaging approach to empathy. J Cogn Neurosci. 19(8):1354-72
Sturm VE, Rosen HJ, Allison S, Miller BL, and Levenson RW. 2006. Self-conscious emotion deficits in frontotemporal lobar degeneration. Brain 129: 2508-2516.
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