Scientists aimed to improve our understanding of how humans developed the ability to comprehend what others might be thinking or feeling. These insights could eventually help in addressing mental health issues like anxiety and depression.
We’ve all experienced it. After leaving a social gathering, our thoughts race with doubts about how we were perceived. “Did I talk too much?” “Did my joke upset anyone?” “Were they enjoying themselves?”
In a recent study by Northwestern Medicine, researchers explored how our ability to consider the thoughts and emotions of others has evolved over time. The outcomes of this research may inform future treatments for mental health challenges like anxiety and depression.
“We often find ourselves contemplating, ‘What is going on in that person’s mind? Did I offend them?'” stated Rodrigo Braga, the study’s senior author. “The regions in our brains that make this possible have grown significantly in our evolutionary history, indicating that this capability has developed relatively recently. Essentially, it entails stepping into another person’s perspective and making educated guesses about their thoughts, even when we can’t be certain.”
The research revealed a continuous communication between the recently evolved areas of the human brain that facilitate social interactions — known as the social cognitive network — and an ancient brain structure called the amygdala.
The amygdala, often described as our “lizard brain,” is traditionally linked to recognizing threats and responding to fear. For example, when someone sees a snake, their body reacts with a jumpy response, increased heart rate, and sweating. However, Braga notes that the amygdala’s functions extend beyond this reactive behavior.
“The amygdala also governs essential social behaviors such as parenting, mating, aggression, and how we navigate social hierarchies,” explained Braga, who is an assistant professor of neurology at Northwestern University’s Feinberg School of Medicine. “While previous studies highlighted some co-activation between the amygdala and social cognitive network, our research is groundbreaking because it shows this communication is ongoing.”
The study was published on November 22 in the journal Science Advances.
Importance of high-resolution brain scans
Within the amygdala exists a specific area called the medial nucleus, crucial for social behaviors. This study is the first to indicate that the medial nucleus of the amygdala is connected to the newer regions of the social cognitive network, which focus on understanding others. This connection enhances the social cognitive network’s capabilities by allowing it to tap into the amygdala’s function of processing emotionally charged information.
This breakthrough was achievable due to functional magnetic resonance imaging (fMRI), a non-invasive technique that monitors brain activity by measuring blood oxygen level fluctuations. Collaborator Kendrick Kay from the University of Minnesota contributed fMRI data from six participants, taken from the Natural Scenes Dataset (NSD). These high-resolution scans offered insights into the social cognitive network previously undetectable with lower-resolution imaging and enabled the researchers to confirm their results multiple times for each participant.
“One of the most thrilling aspects is our ability to reveal network areas that were previously overlooked,” remarked Edmonds, a neuroscience Ph.D. candidate in Braga’s lab. “Our study brought this to light thanks to the exceptional quality of the data we acquired.”
Therapeutic possibilities for anxiety and depression
Both anxiety and depression involve heightened activity in the amygdala, which can lead to overwhelming emotional responses and difficulties in emotional regulation, according to Edmonds. Currently, individuals with these conditions might undergo deep brain stimulation treatments. However, due to the amygdala’s deep location in the brain, this procedure is quite invasive. The findings from this study suggest that less invasive treatments like transcranial magnetic stimulation (TMS) could be refined to target this brain connection more effectively.
“With our understanding that the amygdala links to other brain areas—potentially some closer to the skull, which are simpler to access—TMS could potentially focus on the amygdala by targeting these adjacent regions,” Edmonds explained.
The study is titled, “The human social cognitive network contains multiple regions within the amygdala.” Other co-authors from Northwestern include Christina Zelano, Joseph J. Salvo, Nathan Anderson, Maya Lakshman, and Qiaohan Yang.
