Ventrolateral prefrontal cortex in macaques guides decisions in different learning conditions

Area of Science:

• Neuroscience
• Cognitive Science
• Decision Science

Background:

• Flexible behavioral adjustment is vital for maximizing rewards in changing environments.
• The ventrolateral prefrontal cortex (vlPFC) is involved in learning and decision-making under uncertainty, but its specific roles in new learning versus choice selection are unclear.

Purpose of the Study:

• To investigate the distinct roles of vlPFC in novel association learning versus decision-making between probabilistic rewards.
• To explore the functional connectivity and neurochemical modulation of vlPFC during these processes.

Main Methods:

• Functional neuroimaging (fMRI) was used in rhesus macaques performing a probabilistic reward task with novel and familiar conditions.
• Pharmacological blockade of dopamine D2 receptors was employed to assess its impact on behavior and brain activity.

Main Results:

• vlPFC activity encoded rewards regardless of learning, but specifically encoded win-stay/lose-shift strategies in the novel learning condition.
• Functional connectivity patterns between vlPFC and other brain regions (anterior cingulate cortex, mediodorsal thalamus) differed based on learning context and behavioral strategy.
• Dopamine D2 receptor blockade modulated learning strategies and resting-state vlPFC activity.

Conclusions:

• The study reveals a specialized role for vlPFC-linked circuits in novel association learning.
• Cortical and subcortical interactions within these circuits, modulated by dopamine D2 receptors, are critical for guiding decision strategies during learning.