Sad faces increase the heartbeat-associated interoceptive information flow within the salience network: a MEG study

Area of Science:

• Neuroscience
• Cognitive Science
• Psychophysiology

Background:

• The somatic marker hypothesis highlights the role of visceral signals in emotional processing.
• Understanding brain-body interactions in emotional perception is crucial but underexplored.
• Previous research has not examined information flow among visceral processing regions during emotion perception.

Purpose of the Study:

• To investigate the cortical processing of visceral signals during emotional perception.
• To examine information flow between brain regions involved in interoception and emotional processing.
• To test the hypothesis that heartbeat processing is modulated by emotional stimuli.

Main Methods:

• Magnetoencephalography (MEG) was used to record brain activity in 32 healthy participants.
• Heartbeat-evoked responses (HERs) were measured to assess cortical processing of heartbeats.
• Granger causality analysis and surrogate R-peak analysis were employed to determine information flow and temporal locking.

Main Results:

• Perception of sad faces modulated heartbeat-evoked responses (HERs).
• Modulation effects were observed in prefrontal cortices, globus pallidus, and the interoceptive network (right anterior insula [RAI] and dorsal anterior cingulate cortex [RdACC]).
• Granger causality analysis demonstrated increased heartbeat information flow from the RAI to the RdACC during sad face perception, time-locked to heartbeats.

Conclusions:

• This study provides the first evidence of altered information flow between the RAI and RdACC during emotional perception.
• Findings support the role of interoceptive signals, specifically heartbeats, in modulating emotional processing.
• The results advance the understanding of neural mechanisms underlying brain-body interactions in emotion.