Heartbeat on hold: cortical processing of cardiac signals during motor preparation

• Proactive inhibition contexts selectively improved cortical cardiac signal processing during motor preparation • Heartbeat-Evoked Potential (HEP) amplitudes were significantly higher during motor preparation in the High Proactive Inhibition (HPI) context • Heartbeat-Evoked Potential did not show context-driven effects during the inter-stimulus phase • Enhanced Heartbeat-Evoked Potential modulation was independent of cardiac deceleration • Proactive motor inhibition modulates cortical processing of cardiac signals, reflected in increased Heartbeat-Evoked Potential (HEP) amplitude during motor preparation in high-inhibition contexts. • HEP responses dynamically change throughout a motor trial, with specific enhancement during the motor preparation phase. • Cardiac-brain interactions contribute to motor control, with enhanced cortical cardiac signal encoding occurring independently of cardiac deceleration. • Proactive inhibition dampens motor readiness, as shown by slower reaction times and reduced readiness potential (BP) in high-inhibition contexts. The brain and heart work together to optimize responses to environmental demands, with cardiac signals influencing perception and action. Cardiac deceleration, often associated with response inhibition, enhances the brain's ability to encode stimuli and prepare for action, minimizing interference from internal signals. While this adaptive mechanism facilitates motor preparation, the reciprocal influence of cardiac signals and motor inhibition at the cortical level remains unclear. This study investigated whether context-driven motor inhibition modulates cortical cardiac signal processing, as measured by the Heartbeat-Evoked Potential (HEP). Participants completed a Go/No-Go task with two contexts: low proactive inhibition (LPI, infrequent No-Go stimuli) and high proactive inhibition (HPI, frequent No-Go stimuli). EEG and ECG analyses focused on HEPs during the pre-stimulus phase, with the hypothesis that HPI would enhance HEP amplitude, particularly during motor preparation (HEP2). Consistent with proactive inhibition strategies, participants displayed slower reaction times and reduced readiness potential (BP) amplitudes in the HPI condition, indicating reduced motor engagement during preparation compared to LPI. Crucially, HEP2 amplitudes were significantly higher during motor preparation in the HPI context, while no context-driven effects were observed for HEP1. Importantly, this modulation was independent of broader physiological adjustments, including cardiac deceleration. These findings suggest that proactive inhibition contexts specifically enhance cardiac signal processing during motor preparation. This modulation highlights a functional link between cardiac processing and motor inhibition, likely serving an adaptive role in optimizing physiological and cognitive readiness for scenarios requiring restraint and control.