Exploring influence of subliminal interoception on whole-brain functional network connectivity dynamics

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Psychophysiology

Background:

• Resting-state functional magnetic resonance imaging (fMRI) reveals dynamic interactions among intrinsic connectivity networks (ICNs).
• The origins of temporal fluctuations in functional connectivity, particularly during resting states, remain under investigation.
• Interoception, the sense of the body's internal state, is hypothesized to influence brain network dynamics.

Purpose of the Study:

• To investigate whether subtle interoceptive differences, induced by bladder distention, affect the dynamics of whole-brain functional network connectivity.
• To explore the relationship between visceral sensations and time-varying functional connectivity patterns in the human brain.

Main Methods:

• Healthy female participants (n=15) underwent resting-state fMRI under varying interoceptive conditions (catheterization, bladder filling).
• High-dimensional independent component analysis (ICA) parcellated brain data into 75 components, with 33 identified as non-artifactual ICNs.
• Dynamic functional network connectivity (dFNC) was analyzed using sliding-time window and k-means clustering, with comparisons made using paired t-tests and corrected for multiple comparisons.

Main Results:

• No statistically significant differences in dFNC were detected between interoceptive conditions after correction for multiple comparisons (p<0.05).
• However, distinct dwell times were observed in different (pseudo-)resting states.
• Under more liberal statistical criteria (uncorrected p<0.005), differences in dFNC were noted, particularly involving salience, subcortical, sensorimotor, cerebellar, and brainstem networks.

Conclusions:

• While significant alterations in dFNC were not confirmed, the observed differences in dwell times suggest that interoceptive states may subtly influence the temporal dynamics of brain network interactions.
• Further research is needed to elucidate the precise impact of internal bodily sensations on time-varying functional connectivity and ICN interplay.