“We’ve all been there. Moments after leaving a party, our brains are suddenly filled with intrusive thoughts about what other people were thinking. Did I talk too much? Have I offended them. And these intrusive thoughts can run all night or even for several nights.
The initial goal of the research was to better understand how humans evolved to be able to think about others and how newer regions of the brain support social interactions and how they are connected and in constant communication with the amygdala, older.
The study is the first to map new details of the brain’s social cognitive network with fMRI and to begin to decipher this form of rumination. The brain imaging technique makes it possible to measure brain activity, in different regions of the brain, by detecting changes in blood oxygen levels.
How did humans evolve to start thinking about what’s going on in the minds of others?
We know that the parts of the brain that allow us to do this thinking are found in regions of the human brain that developed more recently during our evolution, which suggests that the cognitive process is itself recent;
The analysis reveals in fact that during this process,
- The more evolved and advanced brain regions of the human brain that support social interactions or social cognitive network are connected and are in constant communication with the older area of the amygdala. This older region, sometimes called
the “reptilian brain”
is associated with threat detection and fear processing. A classic example of the amygdala in action is a person’s physiological and emotional response to the sight of a snake. However, the amygdala is also involved in other functions including certain social behaviors such as parenting, mating, aggression and navigation in social hierarchies.
- activation of the amygdala and the social cognitive network is simultaneous and continuous;
- in the amygdala, a specific area, the medial nucleus, plays a key role in social behaviors;
- the middle core is connected to newly developed regions of the social cognitive network, involved in thinking about others, and sometimes in rumination;
- this continuous link helps shape the function of the social cognitive network by giving it access to the role of the amygdala in processing emotionally important content;
- segments of the social cognitive network connected with the amygdala are identified for the first time, thanks to these very high resolution data.
Implications for the treatment of anxiety and depression: These 2 common disorders involve overactivity of the amygdala, which promotes excessive emotional responses and impaired emotional regulation. Deep brain stimulation finds its basis here, but since the amygdala is located deep in the brain, directly behind the eyes, this means invasive surgery. Thanks to the results of this study, a much less invasive procedure, transcranial magnetic stimulation (TMS), seems able to regulate this emotional stress.
“Now knowing that the amygdala is connected to other regions of the brain closer to the skull, TMS could target the amygdala via these other regions.”
Health
