Three systems of insular functional connectivity identified with cluster analysis.

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Neuroimaging

Background:

• The insular cortex plays a crucial role in various cognitive functions, yet its functional subdivisions in humans remain underexplored.
• Previous research has primarily focused on the general functions of the insula, with limited investigation into its distinct anatomical and functional parts.

Purpose of the Study:

• To functionally parcellate the human insular lobe using resting-state functional connectivity magnetic resonance imaging (fMRI).
• To identify distinct subregions within the insula based on their unique connectivity patterns.
• To investigate the functional roles of these identified subregions in processing emotional stimuli.

Main Methods:

• Utilized resting-state functional connectivity magnetic resonance imaging (fMRI) data from human participants.
• Computed connectivity maps for each voxel within the insula.
• Applied cluster analysis to segregate voxels into distinct functional subregions based on connectivity patterns.

Main Results:

• Identified three distinct insular subregions: a posterior region connected to somatomotor cortices, a dorsal anterior-middle region linked to a control network, and a ventral anterior region connected to the pregenual anterior cingulate cortex.
• Demonstrated that the dorsal and ventral anterior insula subregions selectively responded to disgusting images in a separate task-based fMRI dataset.
• The posterior insula did not show a selective response to disgusting images, highlighting functional specialization.

Conclusions:

• Clustering of functional connectivity patterns is a viable method for subdividing the cerebral cortex, including the insula, into meaningful anatomical and functional regions.
• The identified insular subregions exhibit distinct connectivity profiles and differential responses to emotional stimuli, suggesting specialized roles.
• These findings provide a valuable framework for future research into the complex functions of the human insula.