Why did I say that?! And why do I overthink social interactions?
An insight into why we overthink could have implications for treating anxiety and depression.
Researchers at Northwestern University (IL, USA) have used fMRI to map the human brain’s social cognitive network and its connection to the amygdala, providing us with a better understanding of why we overthink interactions with others. In their pursuit of understanding how humans evolved to develop theory of mind, the researchers may have found clues as to how we can treat psychiatric conditions, such as anxiety and depression.
Theory of mind – the ability to reason about another’s intentions and beliefs – is a crucial part of social cognition and plays a key role in directing social interactions. It has been previously shown that the cortical areas involved in social processing can be classified as two parallel networks, which process theory of mind-related activity and mental scene construction for emotional pain-related activity separately. The cortical parts of the brain associated with theory of mind reasoning are later to develop than other brain areas, and they are disproportionately expanded in the human lineage.
The research team sought to understand how the social cognition network specifically contributes to theory of mind processing. They hypothesized that its specialized social cognition processing ability is due to its connection to the amygdala and other medial temporal lobe structures associated with social cognition.
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In the current study, the team used a noninvasive technique called fMRI, which measures brain activity via changes in blood oxygen levels, to image the brains of six participants. They found that the networks associated with social cognition are connected to and in constant communication with the amygdala, specifically a structure within the amygdala called the medial nucleus. “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,” commented senior author Rodrigo Braga.
The amygdala is an ancient brain structure, found in lizards and humans alike, that is located directly behind the eyes in the medial temporal lobe, making it a difficult structure to explore noninvasively. The amygdala is known for its involvement in processing fear and detecting threats, but it is also implicated in behaviors like parenting, mating and aggression. Learning that our social network is in constant communication with the amygdala suggests that overthinking may be driven by this brain structure in coordination with our social cognition network.
Anxiety and depression both demonstrate amygdala hyperactivity, which can lead to heightened emotional responses and impaired emotional regulation. Currently, someone experiencing either condition could receive deep brain stimulation, but this is an invasive procedure. The study’s findings mean that the social cognition areas, situated on the cortical surface, could potentially be stimulated noninvasively via transcranial magnetic stimulation to modulate the amygdala in individuals experiencing these psychiatric conditions.
In future, the researchers hope to explore this connection between the amygdala and the social cognition network further, potentially identifying ways to modulate activity in the amygdala to treat anxiety and depression.
