Anatomical connectivity-based parcellation of the human orbitofrontal cortex.

The orbitofrontal cortex (OFC) is critical for learning and decision making, but its organization in terms of anatomical connections to other brain areas is not well understood in humans. Here we used diffusion magnetic resonance imaging and probabilistic tractography to characterize the cortical and subcortical white matter connections of the human OFC. We found widespread connectivity of the OFC with frontal and temporal cortices, anterior cingulate, insula, olfactory cortex, as well as the striatum, hippocampus, amygdala, and thalamic nuclei. We then used k-means clustering to parcellate the OFC into different subregions based on these connections, revealing a medial-lateral division with two clusters, and a separation into medial, lateral-anterior, and lateral-posterior subdivisions with three clusters. Higher order parcellations revealed more complex subdivisions mirroring cytoarchitectural boundaries of the primate OFC. Analysis of the white matter connectivity of the medial and lateral OFC clusters revealed differences in their connectivity patterns with frontal cortices, insula, olfactory cortex, anterior cingulate cortex, as well as the striatum and several thalamic nuclei. In addition, lateral-anterior and lateral-posterior OFC clusters showed different connectivity strengths with several frontal cortices, anterior cingulate cortex, insula, and the caudate. These findings suggest parallels between the anatomical organization of the human and macaque OFC and may help to elucidate how the OFC contributes to adaptive behavior. (PsycInfo Database Record (c) 2025 APA, all rights reserved).