Summary: A new study uncovers constant communication between the human brain’s social cognitive network, responsible for understanding others’ thoughts, and the amygdala, known for processing fear and emotions. High-resolution brain scans revealed that this connection helps the brain integrate emotional importance into social interactions.
This insight could lead to non-invasive treatments like transcranial magnetic stimulation (TMS) for anxiety and depression by targeting these regions. The findings highlight how evolutionary brain expansion enhances social understanding while linking it to ancient emotional processing centers.
Key Facts:
- The social cognitive network constantly communicates with the amygdala, shaping emotional and social behaviors.
- High-resolution brain imaging identified new network regions and their link to the amygdala.
- Findings could inform non-invasive treatments for anxiety and depression by targeting connected regions.
Source: Northwestern University
We’ve all been there. Moments after leaving a party, your brain is suddenly filled with intrusive thoughts about what others were thinking. “Did they think I talked too much?” “Did my joke offend them?” “Were they having a good time?”
In a new Northwestern Medicine study, scientists sought to better understand how humans evolved to become so skilled at thinking about what’s happening in other peoples’ minds.
The findings could have implications for one day treating psychiatric conditions such as anxiety and depression.
“We spend a lot of time wondering, ‘What is that person feeling, thinking? Did I say something to upset them?’” said senior author Rodrigo Braga.
“The parts of the brain that allow us to do this are in regions of the human brain that have expanded recently in our evolution, and that implies that it’s a recently developed process.
“In essence, you’re putting yourself in someone else’s mind and making inferences about what that person is thinking when you cannot really know.”
The study found the more recently evolved and advanced parts of the human brain that support social interactions — called the social cognitive network — are connected to and in constant communication with an ancient part of the brain called the amygdala.
Often referred to as our “lizard brain,” the amygdala typically is associated with detecting threats and processing fear. A classic example of the amygdala in action is someone’s physiological and emotional response to seeing a snake: startled body, racing heart, sweaty palms. But the amygdala also does other things, Braga said.
“For instance, the amygdala is responsible for social behaviors like parenting, mating, aggression and the navigation of social-dominance hierarchies,” said Braga, an assistant professor of neurology at Northwestern University Feinberg School of Medicine.
“Previous studies have found co-activation of the amygdala and social cognitive network, but our study is novel because it shows the communication is always happening.”
The study was published Nov. 22 in the journal Science Advances.
High-resolution brain scans were key
Within the amygdala, there’s a specific part called the medial nucleus that is very important for social behaviors. This study was the first to show the amygdala’s medial nucleus is connected to newly evolved social cognitive network regions, which are involved in thinking about other people.
This link to the amygdala helps shape the function of the social cognitive network by giving it access to the amygdala’s role in processing emotionally important content.
This was only possible because of functional magnetic resonance imaging (fMRI), a noninvasive brain-imaging technique that measures brain activity by detecting changes in blood oxygen levels.
A collaborator at the University of Minnesota and co-author on the study, Kendrick Kay, provided Braga and co-corresponding author Donnisa Edmonds with fMRI data from six study participants’ brains, as part of the Natural Scenes Dataset (NSD).
These high-resolution scans enabled the scientists to see details of the social cognitive network that had never been detected on lower-resolution brain scans. What’s more, they were able to replicate the findings up to two times in each individual.
“One of the most exciting things is we were able to identify network regions we weren’t able to see before,” said Edmonds, a neuroscience Ph.D. candidate in Braga’s lab at Northwestern.
“That’s something that had been underappreciated before our study, and we were able to get at that because we had such high-resolution data.”
Potential treatment of anxiety, depression
Both anxiety and depression involve amygdala hyperactivity, which can contribute to excessive emotional responses and impaired emotional regulation, Edmonds said.
Currently, someone with either condition could receive deep brain stimulation for treatment, but since the amygdala is located deep within the brain, directly behind the eyes, it means having an invasive, surgical procedure.
Now, with this study’s findings, a much less-invasive procedure, transcranial magnetic stimulation (TMS), might be able to use knowledge about this brain connection to improve treatment, the authors said.
“Through this knowledge that the amygdala is connected to other brain regions — potentially some that are closer to the skull, which is an easier region to target — that means people who do TMS could target the amygdala instead by targeting these other regions,” Edmonds said.
About this neuroscience, emotion, and social skills research news
Author: Kristin Samuelson
Source: Northwestern University
Contact: Kristin Samuelson – Northwestern University
Image: The image is credited to Neuroscience News
Original Research: Open access.
“The human social cognitive network contains multiple regions within the amygdala” by Rodrigo Braga et al. Science Advances
Abstract
The human social cognitive network contains multiple regions within the amygdala
Reasoning about someone’s thoughts and intentions—i.e., forming a “theory of mind”—is a core aspect of social cognition and relies on association areas of the brain that have expanded disproportionately in the human lineage.
We recently showed that these association zones comprise parallel distributed networks that, despite occupying adjacent and interdigitated regions, serve dissociable functions. One network is selectively recruited by social cognitive processes. What circuit properties differentiate these parallel networks?
Here, we show that social cognitive association areas are intrinsically and selectively connected to anterior regions of the medial temporal lobe that are implicated in emotional learning and social behaviors, including the amygdala at or near the basolateral complex and medial nucleus.
The results suggest that social cognitive functions emerge through coordinated activity between internal circuits of the amygdala and a broader distributed association network, and indicate the medial nucleus may play an important role in social cognition in humans.
