Oscillatory markers of interoceptive attention: beta suppression as a neural signature of heartbeat processing

Interoceptive attention refers to the process of selectively attending to internal bodily signals to guide perception and behavior. Cardiac interoception, in particular, has been proposed to play a key role in self-regulation and emotional awareness, yet the neural dynamics underlying attention to cardiac signals remain incompletely understood. Here, we investigated whether heartbeat-locked beta-band (16–28 Hz) activity can serve as an oscillatory marker of interoceptive attention. Using magnetoencephalography (MEG), we recorded neural activity from 51 healthy participants performing heartbeat and an auditory discrimination task. Time-frequency analysis revealed significant suppression of beta-band power 310–530 ms after the R-peak, localized to somatosensory cortex, premotor cortex, dorsolateral prefrontal cortex, and midline cingulate regions. This heartbeat-locked beta suppression was present not only during task conditions but also at rest, suggesting it may reflect ongoing, automatic processing of cardiac signals. However, the magnitude of suppression was significantly enhanced during interoceptive attention. Moreover, greater beta suppression in the somatosensory and anterior cingulate cortices correlated with higher interoceptive accuracy across individuals. Control analyses confirmed that the observed effect was time-locked to actual cardiac events and not present in surrogate epochs or explained by heart rate variability. These findings suggest that beta suppression reflects a temporally specific cortical response to cardiac input, modulated by top-down attention. The results identify beta-band suppression as a potential oscillatory marker of interoceptive attention and provide a foundation for future studies examining interoceptive processing in both healthy and clinical populations.