Bilateral Orbital Prefrontal Cortex Lesions in Rhesus Monkeys Disrupt Choices Guided by Both Reward Value and Reward Contingency

Alicia Izquierdo, Robin K. Suda, Elisabeth A. Murray

Journal of Neuroscience • 2004

DOI PMC

Object Reversal Learning

behavioralrhesus monkey

Objective: Test whether the orbital prefrontal cortex (PFo) is necessary for guiding behavior based on reward value and reward contingency by comparing object reversal learning performance in monkeys with bilateral PFo lesions versus unoperated controls

Protocol Steps

Object Reversal Learning Task

Monkeys are tested on a standard test of flexible stimulus-reward learning where they must learn to reverse their choices based on changing stimulus-reward contingencies

Note: This is a standard test of flexible stimulus-reward learning assessing the ability to alter choices when reward contingencies change

View evidence from paper

“tested on a standard test of flexible stimulus-reward learning, namely object reversal learning”

Assessment Timing - Initial Post-Surgery

First assessment of object reversal learning performance conducted shortly after bilateral PFo removal surgery

Note: Comparison made between operated monkeys and unoperated controls

View evidence from paper

“one performed shortly after surgery”

Assessment Timing - Delayed Post-Surgery

Second assessment of object reversal learning performance conducted approximately 19 months after bilateral PFo removal surgery

approximately 19 months post-surgery

Note: Allows assessment of long-term effects of PFo lesions on reversal learning

View evidence from paper

“the other ≈19 months after surgery”