Overthinking? It's your primitive brain debating with advanced brain parts
A recent study by Northwestern Medicine has highlighted the human tendency to overthink social interactions. The research, led by senior author Rodrigo Braga, examined how humans have evolved to be good at thinking about others' thoughts and feelings. "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," Braga explained.
'Lizard brain' and social cognitive network
The study found that our brain's social parts are constantly in touch with an older part called the amygdala. This ancient brain region, commonly referred to as our "lizard brain," is mainly involved in threat detection and fear processing. But, as Braga noted, it also contributes to social behaviors such as parenting, mating, aggression, and traversing social dominance hierarchies.
Amygdala's role in social cognition
The research pinpointed a particular region in the amygdala, called the medial nucleus, that plays an important role in social behaviors. This is the first study to show that this region of the amygdala is linked to newly evolved regions associated with social cognition. The link was established using functional magnetic resonance imaging (fMRI), a noninvasive brain-imaging technique that detects changes in blood oxygen levels to measure brain activity.
High-resolution brain scans reveal new findings
The study's co-corresponding author, Donnisa Edmonds, emphasized the importance of high-resolution brain scans in their research. "One of the most exciting things is we were able to identify network regions we weren't able to see before," Edmonds said. With these detailed images, scientists were able to see elements of the social cognitive network that had gone undetected in previous lower-resolution brain scans.
Discoveries could improve treatment for mental health conditions
The research also holds potential implications for treating mental health conditions such as anxiety and depression, which are often associated with hyperactivity in the amygdala. Today, deep brain stimulation is employed as a treatment method but it involves an invasive surgical procedure due to the amygdala's location. However, with these new findings about brain connections, a less invasive procedure called transcranial magnetic stimulation (TMS) could potentially be employed to target other regions connected to the amygdala.
