Summary: Researchers have discovered how specific brain circuits process empathy, showing that witnessing others in pain activates the same neural pathways as experiencing pain directly. Using advanced imaging techniques, the study pinpointed neurons in the anterior cingulate cortex (ACC) that respond both to personal distress and observed distress in others.
The scientists further demonstrated that signals from the ACC to the brain’s periaqueductal gray (PAG) region are crucial for transforming empathy into behavioral responses, like freezing or avoidance. Manipulating this ACC-to-PAG pathway directly affected empathic behaviors, confirming its vital role in translating observed pain into emotional reactions.
These findings clarify the neural basis of empathy, which could inform treatments for conditions involving impaired emotional or social processing, such as autism, schizophrenia, or PTSD.
Key Facts:
- Shared Neural Activation: Neurons in the ACC activate similarly whether experiencing pain firsthand or observing another in pain.
- Empathy Circuit Identified: The ACC-to-PAG neural pathway specifically processes emotional responses to observed distress.
- Behavioral Impact: Disrupting the ACC-to-PAG connection significantly reduces empathic behaviors, demonstrating its critical role.
Source: Institute for Basic Science
Empathy—the ability to share and understand the emotions of others—is a cornerstone of human social interactions.
When we witness someone in pain, we often experience a mirrored emotional response, a phenomenon known as affect sharing. While this ability is essential for social bonding and survival, the precise neural mechanisms behind empathy remain largely unknown.
A research team led by Dr. KEUM Sehoon at the Center for Cognition and Sociality (CCS) within the Institute for Basic Science (IBS) in South Korea has uncovered key insights into how the brain processes others’ distress.
Using miniature endoscopic calcium imaging, the researchers identified specific neural ensembles in the anterior cingulate cortex (ACC) that encode empathic freezing, a behavioral response in which an observer reacts with fear when witnessing distress in others.
To investigate this phenomenon, the team conducted a series of real-time brain imaging experiments in mice, tracking individual neurons as they observed another mouse experiencing mild foot shocks.
The results showed that specific ACC neurons were activated both when the observer experienced pain firsthand and when they witnessed another in pain, reinforcing the idea that observing distress triggers a neural response similar to direct pain experience.
The study further revealed that ACC population activity during empathic freezing closely resembles the neural representation of affective—rather than sensory—aspects of direct pain experiences.
This suggests that witnessing another’s pain triggers activation in the ACC as if the observer were experiencing pain themselves, highlighting the ACC’s specialized role in processing the emotional aspects of pain.
Further analysis revealed that ACC neurons projecting to the periaqueductal gray (PAG), a brain region involved in fear and pain regulation, selectively conveyed emotional pain information. The researchers used optogenetics, a technique that enables precise control of neural activity with light, to manipulate this pathway.
When they inhibited the ACC-to-PAG circuit, empathic freezing, and pain avoidance behaviors were significantly reduced. This confirms that this pathway transforms perceived distress into behavioral responses, reinforcing its crucial role in affective empathy.
Unlike previous studies that focused on animals with prior pain experience, this study used naïve observer mice with no previous exposure to pain, allowing the researchers to examine pure emotional contagion without the influence of past experiences. This approach provides new insights into the fundamental neural mechanisms of affective empathy.
Understanding how the brain encodes empathy could have major implications for mental health research. Conditions such as autism spectrum disorder (ASD), antisocial personality disorder, PTSD, and schizophrenia often involve difficulties in processing social and emotional cues.
By identifying the specific brain circuits involved in affect sharing, scientists may develop new strategies for treating these disorders.
Dr. Keum stated, “Our findings pinpoint the specific brain circuits involved in processing others’ pain emotionally, offering a foundation for new approaches to studying empathy-related neuropsychiatric disorders.”
About this empathy and neuroscience research news
Author: William Suh
Source: Institute for Basic Science
Contact: William Suh – Institute for Basic Science
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Cortical representations of affective pain shape empathic fear in male mice” by KEUM Sehoon et al. Nature Communications
Abstract
Cortical representations of affective pain shape empathic fear in male mice
Affect sharing, the ability to vicariously feel others’ emotions, constitutes the primary component of empathy. However, the neural basis for encoding others’ distress and representing shared affective experiences remains poorly understood.
Here, using miniature endoscopic calcium imaging, we identify distinct and dynamic neural ensembles in the anterior cingulate cortex (ACC) that encode observational fear across both excitatory and inhibitory neurons in male mice.
Notably, we discover that the population dynamics encoding vicarious freezing information are conserved in ACC pyramidal neurons and are specifically represented by affective, rather than sensory, responses to direct pain experience.
Furthermore, using circuit-specific imaging and optogenetic manipulations, we demonstrate that distinct populations of ACC neurons projecting to the periaqueductal gray (PAG), but not to the basolateral amygdala (BLA), selectively convey affective pain information and regulate observational fear.
Taken together, our findings highlight the critical role of ACC neural representations in shaping empathic freezing through the encoding of affective pain.
