Subcortical Substrates of Explore-Exploit Decisions in Primates

Area of Science:

• Neuroscience
• Decision Science
• Behavioral Economics

Background:

• The explore-exploit dilemma is central to decision-making, balancing immediate rewards with potential future gains.
• Motivational neural circuits are known to support learning from past outcomes, but their role in guiding exploration remains unclear.

Purpose of the Study:

• To investigate the neural mechanisms underlying the explore-exploit dilemma.
• To determine if subcortical motivational circuits, specifically the amygdala and ventral striatum, contribute to exploration decisions.

Main Methods:

• Recorded neural activity in the amygdala and ventral striatum of rhesus macaques performing an explore-exploit task.
• Utilized a partially observable Markov decision process (POMDP) model to quantify explore-exploit trade-offs.

Main Results:

• The ventral striatum and amygdala exhibit distinct neural representations related to exploitative and exploratory choices.
• Neural activity differentiated between the immediate value of exploitation and the future value of exploration.

Conclusions:

• Subcortical motivational circuits, including the amygdala and ventral striatum, play a critical role in guiding explore-exploit decisions.
• These brain regions are essential for balancing current rewards with the pursuit of potentially greater future rewards.