Dynamic functional network connectivity reveals unique and overlapping profiles of insula subdivisions

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Brain Imaging

Background:

• The human insular cortex has diverse subdivisions involved in functions from interoception to cognitive control.
• Understanding the functional connectivity of these subdivisions is crucial due to their varied roles.

Purpose of the Study:

• To investigate the functional connectivity profiles of four distinct insula subdivisions using static- and dynamic functional network connectivity (s-FNC and d-FNC) analyses.
• To explore the dynamic connectivity states of the insula and how they differ from static connectivity.

Main Methods:

• Applied k-means clustering to sliding windows for dynamic functional network connectivity (d-FNC) analysis.
• Compared d-FNC results with static functional network connectivity (s-FNC) findings for four insula subdivisions: dorsal anterior (dAI), ventral (VI), posterior (PI), and middle (MI).

Main Results:

• Static-FNC confirmed a cognition-emotion-interoception division within the insula (dAI-frontal, VI-limbic, PI/MI-sensorimotor).
• Dynamic-FNC revealed a common state mirroring the s-FNC division, alongside less frequent states with overlapping and unique subdivision connectivity.
• The dorsal anterior insula (dAI) showed the most variable connections and unique dynamic links with the default mode network.

Conclusions:

• Dynamic-FNC captures crucial functional dynamics of the insula that static-FNC may miss.
• The insula exhibits dynamic functional connections, highlighting its temporal flexibility across various cognitive and emotional tasks.