Parcellation of functional sub-regions from fMRI: A graph clustering based approach

•A novel, computationally efficient framework for parcellating a single brain region-of-interest into spatially-contiguous functional sub-regions is proposed.•A connectivity network generation approach is proposed that takes into account the connectivity and spatial distance between voxels in the target ROI as well as their dissimilarity in connectivities with other brain reference ROIs.•A community detection algorithm is applied to sub-divide the generated network into several functionally connected and spatially contiguous subROIs.•The framework is applied to synthetic data where it shows favorable results in the presence of noise compared to current approaches. When applied to resting state fMRI data from nine healthy subjects, the putaminal region was parcellated into two functional sub-regions, consistent with prior anatomical knowledge.