Social cognitive regions of human association cortex are selectively connected to the amygdala.
This paper is neat in a lot of ways. On one level they repeat and confirm other work at higher resolution (7 Tesla MRI instead of 3 Tesla). On another level did you know the Default Mode Network (DMN) has substructure? And overlaps with Theory of Mind brain networks?
The DMN is the part of the brain that is active when we aren’t paying attention to anything externally, daydreaming, introspecting…the paper also points out that the same regions also involve Theory of Mind, autobiographical memory, self-oriented thought, “episodic projection” (EP, thinking about the past or future), and mental scene construction.
But it turns out that there’s evidence that some of the above in the DMN use slightly different regions for Theory of Mind vs. EP (anterior vs. posterior regions of the parietal lobe). These putatively separate parts of the DMN were called DM-A (EP and mental scene construction) and DM-B (Theory of Mind).
They not only confirmed that work, they had a high enough resolution to look at the amygdala and other subcortical regions. In fact DN-B and Theory of Mind seems to involve the amygdala basolateral (primary and secondary reinforcement), accessory basal (maybe generalized feelings to me), lateral (sensory input from non-olfactory senses), and medial (innate behavior) nuclei. DN-A did not activate the amygdala.
So our amygdalae are active even when not outwardly focused, or necessarily feeling intense, at least for Theory of Mind tasks. I like any paper that adds structure to how the mind and the brain intersect. Understanding how our thoughts are shaped.
Finally I’m going to stop predicting what I’m going to try to post next. My mind is a mess.