Connectivity-based parcellation of the human orbitofrontal cortex.

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Functional Neuroimaging

Background:

• The primate orbitofrontal cortex (OFC) plays a key role in reward processing, learning, and decision-making.
• While monkey studies suggest OFC subdivisions based on anatomical connections, human OFC functional organization remains poorly understood beyond a medial/lateral distinction.

Purpose of the Study:

• To investigate functional subdivisions of the human OFC based on resting-state functional connectivity.
• To determine if functional parcellation aligns with known primate OFC anatomy and connectivity.

Main Methods:

• Resting-state functional magnetic resonance imaging (fMRI) was employed in human participants.
• Unsupervised machine learning clustering techniques were applied to functional connectivity data to identify OFC subdivisions.

Main Results:

• A hierarchical clustering revealed a finer parcellation of the human OFC than previously established.
• Six distinct clusters were identified: one medial, one posterior-central, one central, and three lateral clusters along the anterior-posterior axis.
• These OFC clusters demonstrated specific connectivity patterns with other cortical and subcortical regions, including the prefrontal cortex, temporal cortex, parietal cortex, striatum, and midbrain.

Conclusions:

• The findings support a more detailed functional parcellation of the human OFC than previously recognized.
• The identified subdivisions show distinct connectivity profiles, suggesting specialized roles in reward processing, learning, and decision-making.
• This functional atlas can guide future research on OFC subdivisions and their specific contributions to complex cognitive functions.