Reward stability determines the contribution of orbitofrontal cortex to adaptive behavior

Area of Science:

• Neuroscience
• Behavioral Science
• Cognitive Psychology

Background:

• The orbitofrontal cortex (OFC) is implicated in flexible behavior and adapting to changing reward contingencies.
• The precise cognitive mechanisms by which the OFC supports adaptive responding remain debated.

Purpose of the Study:

• To investigate the role of the orbitofrontal cortex (OFC) in flexible behavioral adaptation to changing reward contingencies.
• To determine how the frequency of contingency changes influences the performance of animals with OFC lesions.

Main Methods:

• Rats underwent either sham or orbitofrontal cortex (OFC) lesions.
• Subjects performed radial maze tasks with varying frequencies of reward contingency changes.
• Perseverative and non-perseverative errors, win-stay, and lose-shift strategies were measured.

Main Results:

• Sham-lesioned rats outperformed OFC-lesioned rats when contingency changes were rare, showing fewer errors and more adaptive choices.
• When contingency changes were rapid, sham-lesioned rats exhibited impaired performance, making more errors and fewer adaptive shifts compared to OFC-lesioned rats.
• OFC lesions led to deficits in learning and adaptation, particularly under conditions of high reward instability.

Conclusions:

• The orbitofrontal cortex (OFC) plays a critical role in integrating reward history to guide flexible behavior.
• The OFC's contribution to adaptive responding is context-dependent, influenced by the stability of reward outcomes.
• Outcome expectancy signals mediated by the OFC can enhance or hinder performance based on environmental predictability.