How does the brain balance emotion and reason?
Neuroscientists uncover a middleman between cognitive and emotional brain regions
By Molly Gluck
What would life be like if we could only act on emotion? On the flip side, what would happen if no one felt emotion — and we were only guided by reason? Envisioning both scenarios highlights the critical importance of balancing emotion and reason.
Healthy emotional regulation requires communication between cognitive brain regions, like the dorsolateral prefrontal cortex (DLPFC), and emotional brain regions, such as area 25. However, these two areas are weakly connected — and until now, it has been unknown how they interact. Boston University neuroscientists Drs. Helen Barbas, Mary Kate Joyce, Yohan John and and Miguel Ángel García-Cabezas (now at University of Madrid) uncovered a middleman responsible for maintaining emotional equilibrium: area 32.
The researchers identified area 32 using neural tracers to visualize the connections between cognitive (DLPFC) and emotional (area 25) brain regions in rhesus monkeys. Their discovery helps us better understand what makes certain people more susceptible to depression — and can inform different treatment approaches.
In healthy brains, the DLPFC signals area 32 to balance area 25 activity, enabling emotional stability. Emotional balance goes haywire in mood disorders like depression, leading to unchecked negative emotions and an inability to break out of rumination. This runaway negative emotion is often caused by an overactive area 25. The researchers speculate that in individuals where area 32 has weaker connections with DLPFC and area 25, emotional regulation may be more difficult — perhaps rendering individuals vulnerable to depression. Furthermore, identifying and evaluating the strength of area 32’s connections with DLPFC and area 25 can help inform which treatment approach to take for people suffering from depression — ranging from cognitive behavior therapy, to medication, to deep brain stimulation.
So, what do these critical interactions between brain regions actually look like? The researchers take us into their lab for an inside-look:
For more information, access the full research paper, published in the Journal of Neuroscience here.
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