Sonoception: Synthetic auditory stimulation modulates inhibitory control, heart-brain interactions, and insular activity

We present a non-invasive stimulation technique called Sonoception that utilizes synthetic auditory frequencies at 6Hz and 2Hz to modulate behavioral, physiological, and neural responses in healthy humans. In three studies, we investigated the effects of Sonoception on emotional processing and inhibitory control, cortical processing of cardiac signals, and brain activation patterns. In Study 1, participants completed a Go/No-go task with faces showing disgusted or neutral expressions to assess the influence of the auditory stimulation on inhibitory control in emotional contexts. The 6Hz stimulation decreased false alarms for neutral faces, whereas the 2Hz stimulation increased false alarms for disgusted faces. This suggested a facilitatory effect of the 6Hz frequency on inhibitory control and a disinhibitory effect of the 2Hz frequency that enhanced impulsive responses. In Study 2, we assessed the heartbeat-evoked potentials as an index of heart-brain interaction and observed increased amplitude following 6Hz stimulation, suggesting enhanced cortical processing of cardiac signals. In Study 3, passive listening fMRI showed that the 6Hz stimulation selectively activated the left insula compared to the 2Hz condition. Taken together, these findings demonstrate that Sonoception exerts distinct effects on behavioral, physiological, and neural functions, supporting the hypothesis that auditory frequency-specific stimulation can modulate cognitive-emotional functions, brain-body interactions and insular activation patterns.