As social beings, humans have the ability to adapt their behavior to fit their social context. Whether we are meeting new classmates, conducting a job interview or helping a friend who has lost their partner, different situations require the modulation of our speech and our behavioral responses, such as physical proximity or even physical contact – for example when we hug someone who is in pain. Despite the apparent complexity, social adaptation is not only about a rational and elaborated decision-making process, but an unconscious way of understanding certain environmental requirements. This process requires a kind of innate ability, something many of us know as empathy.
We can define empathy as the ability to generate shared representations of affective states in others. In other words, empathy occurs when we are able to see the world through another’s eyes. It’ s a vicarious experience that allows someone to share feelings experienced by those around them and carry out prosocial behavioral responses. In order to explain how this is possible, several social neuroscientists have suggested that empathy elicits brain responses and neural activity similar to experiencing firsthand feelings. Thanks to the development and improvement of neuroimaging techniques, researchers have been able to explore the neural basis of empathy. Shall we take a look at the most relevant discoveries?
Empathy in pain
“[…] the simple knowledge that a loved one is going to be hurt is enough to prepare our brains to link our personal experience to their emotional state (Singer et al., 2004).”
Most of the studies related to this topic during recent decades were made using physical pain as a paradigm. Pain involves both sensory-discriminative and emotional pathways in order to perceive a potentially harmful stimulus and motivate the organism to avoid it. Thus, we might expect similar brain responses in firsthand and vicarious pain experience.
In 2004, Tania Singer – one of the most prominent researchers in the field of empathy – studied the brain activity of females when they were being stimulated with painful shocks compared to seeing their romantic partners receiving the same throbbing stimulation. Using fMRI scanners, Singer and her colleagues discovered a few interesting things:
- Firsthand pain experience activated, as expected, sensory-discriminative and emotional pathways. Primary and secondary somatosensory cortex, as well as areas of the brain related to the affective processing of pain -specifically the anterior portions of the insula and the cingulate cortices-, significantly increased their activity.
- The vicarious experience of seeing their partners suffering consistently activated the anterior insula and cingulate cortices. This suggests that females were able to generate a shared representation of the emotional state of their partners.
- Not only the vicarious experience itself, but also the presence of anticipatory cues can result in increased activity in such areas.
The authors concluded that witnessing pain in others activates the same emotional-related neural circuits as the person who is experiencing it and, most importantly, that the simple knowledge that a loved one is going to be hurt is enough to prepare our brains to link our personal experience to their emotional state (Singer et al., 2004). However, these findings open the door to new questions. If both direct vicarious experience and indirect signals can generate empathic responses, does that mean that the anterior insula and cingulate cortices are central processing structures that could be activated by different neural circuits?
Image 1: Three schematic illustrations including the different brain structures involved in pain. The first illustration shows the somatosensory cortex in pink. Second illustration shows the anterior cingulate cortex (yellow) in a sagittal view whereas the third image includes the anterior insula in blue.
The role of available information: mirror-neuron system vs. theory of mind
Studying the role of the premotor cortex in the voluntary motor control, a team of Italian researchers discovered that these motor networks are not exclusively involved in planning movements. Surprisingly, they also increased their activity in response to the movements of the investigators (di Pellegrino, 1992). Four years later they were named mirror neurons, a well known term that refers to groups of neurons whose activity provides us with a basic mechanism to intuitively understand the actions of others.
Different studies have shown the relationship between the direct empathic experience and the activation of mirror neuron structures located in two separate brain areas, called the prefrontal and the inferior parietal cortex (Keysers & Gazzola, 2007; Rizzolatti et al, 2001). One easy way to understand this is to imagine how looking at someone drinking a disgusting beverage can automatically make us feel that same disgust and even adopt the same facial expression.
Nevertheless, sometimes we do not have all the emotional information available and need to make assumptions about what is happening in a particular situation based on internal and external stimuli. For example, when a friend calls to tell us that he has lost his brother in a traffic accident. Here is where theory of mind – also known as mentalizing – takes place.
“In contrast to our mirror-neuron system, mentalizing requires a conscious and reflexive activity. It is a cognitive process rather than an emotional one.”
Thus, as we do not have an explicit pain signal shown, we need to trigger mentally – and internally – generated imagery processes. Among others, regions of the medial prefrontal cortex or the posterior cingulate cortex are involved in the ability to infer and represent such emotional pain (Lamm et al., 2011).
The dark side of empathy: what about revenge?
It is known that empathetic responses can be modulated by internal variables such as personality traits or the ability to identify and describe emotions and even by external factors. One interesting factor is how we perceive fairness. Singer and colleagues (2006) designed an experiment in which males and females were asked to participate in a game against fair or unfair players. After the game, the brain activity of the participants was analyzed while they observed their opponents being injured. As we know, anterior insula and cingulate cortices of participants increased their activity when fair players received a painful stimulation. By contrast, such areas showed decreased activity while watching the unfair ones. Instead – at least in males – looking at the unfair players being injured significantly activated reinforcement and reward-related structures. Thus, activity in structures related to reward-seeking and decision-making – the nucleus accumbens and orbitofrontal cortex to name a few – correlated with the desire for revenge, providing a neurobiological mechanism that could explain the basis of punitive behavior.
As we have seen, the human brain is built to give us contextual-dependent information destined to modulate our behavior. Different structures are involved in the complex task of intuitively identifying changes in facial expressions or voice modulations and also inferring how our fellows may feel. These mechanisms allow us to make other people’s pain our own to help modulate social interactions. They also seem to play a critical role in detecting a transgressor and depriving him of the community’s empathy. The results obtained over the last few decades of research offer an interesting insights into how social interactions develop among different cultures and how humans made formal methods to control and punish undesirable actions.
Written by Miguel Omar Belhouk Herrero. Feature image illustrated by Gil Torten.
Edited by Edited by Arielle Hogan, Holly Hake, and Zoe Guttman.
What do you think are the major differences between experiencing something firsthand and experiencing something through another’s eyes? Tell us in the comments below!
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Bernhardt, B. C., & Singer, T. (2012). The Neural Basis of Empathy. Annual Review of Neuroscience, 35(1), 1-23.
Di Pellegrino, G., Fadiga, L., Fogassi, L., Gallese, V., & Rizzolatti, G. (1992). Understanding motor events: a neurophysiological study. Experimental Brain Research, 91(1), 176–180.
Keysers, C., & Gazzola, V. (2007). Integrating simulation and theory of mind: from self to social cognition. Trends in Cognitive Sciences, 11(5), 194–196.
Lamm, C., Decety, J., & Singer, T. (2011). Meta-analytic evidence for common and distinct neural networks associated with directly experienced pain and empathy for pain. NeuroImage, 54(3), 2492-2502.
Rizzolatti, G., Fogassi, L., & Gallese, V. (2001). Neurophysiological mechanisms underlying the understanding and imitation of action. Nature Reviews Neuroscience, 2(9), 661–670.
Singer, T., Seymour, B., O’Doherty, J., Kaube, H., Dolan, R. J., & Frith, C. D. (2004) Empathy for pain involves the affective but not sensory components of pain. Science, 303(5661) 1157-1162.
Singer, T., Seymour, B., O’Doherty, J. P., Stephan, K. E., Dolan, R. J., & Frith, C. D. (2006). Empathic neural responses are modulated by the perceived fairness of others. Nature, 439(7075), 466-469.