Spontaneous HRV fluctuations are linked to functional changes in resting state brain activation in younger and older adults.

Functional brain coupling patterns associated with spontaneous HRV changes were identified in multiple brain networks including the anterior cingulate cortex, cerebellum, brainstem, and temporal lobe.

• A functional connectivity multivariate pattern analysis (fc-MVPA) was used to identify these coupling patterns.
• The study used two consecutive fMRI resting state scans combined with physiological HRV data assessed via photoplethysmography (PPG).
• Spontaneous HRV changes were quantified from one resting state scan to the other.
• The identified clusters included the anterior cingulate cortex (ACC), the cerebellum, the brainstem, and the temporal lobe.

The functional brain coupling patterns associated with HRV changes were not significantly different between younger and older adults, indicating age invariance of brain-heart communication.

• The sample consisted of 69 older adults and 134 younger adults.
• Data were drawn from a large open dataset with two consecutive fMRI resting state scans.
• The age-invariant finding suggests that the neural mechanisms underlying brain-heart communication are preserved across age groups.
• The authors describe this as 'age invariance of brain heart communication.'

When HRV increased, there was stronger functional coupling of identified clusters with regions including the insula, opercular cortex, superior frontal gyrus, and cerebellum.

• These findings were identified through post hoc seed-to-voxel analyses.
• The seed regions were the clusters identified in the fc-MVPA analysis.
• The directional relationship showed that HRV increases specifically were associated with this pattern of enhanced functional coupling.
• The authors note this pattern 'is in accordance with prominent theories and provides further insights into the neural mechanisms underlying brain-heart communication.'

The study employed a functional connectivity multivariate pattern analysis (fc-MVPA) approach to examine the unique information about relationships between changes in functional brain coupling and spontaneous HRV changes.

• The dataset included 69 older and 134 younger participants totaling 203 participants.
• HRV data were assessed via photoplethysmography (PPG) during two consecutive fMRI resting state scans.
• The fc-MVPA was used to identify functional brain coupling patterns associated with changes in HRV within brain networks.
• The approach focused on 'unique information about the relationship between changes in functional coupling between brain areas and spontaneous HRV changes.'