New findings show that the voluntary initiation of imagined actions is coupled with respiration, suggesting that the breathing system is involved in preparatory processes of voluntary action.
Several studies have demonstrated that breathing is involved in repetitive and rhythmic motor processes, such as running. In previous work we showed that the initiation of complex actions, such as sets of voluntary hand movements (Park et al., 2020) is also associated with breathing. In the current study, we investigated whether breathing-action coupling is limited to motor actions that are associated with overt movements or whether the breathing system also influences “mental actions” which do not involve any overt movement.
We tested if breathing was associated with two types of mental actions, namely motor imagery (MI) and visual imagery (VI), as well as actual motor execution (ME) while recording continuous electroencephalography (EEG), electrocardiography (ECG), electromyography (EMG), and respiratory signals. Our main finding was that respiration is coupled not only with overt action, but also with the voluntary initiation of mental imagery which do not involve any overt movement. In addition, EEG analysis revealed the existence of readiness potential (RP) waveforms, previously associated with preparation of self-initiated movements, before the initiation of mental actions (MI and VI), suggesting that RP does not request motor movement and that is associated with respiratory phase.
These results show that the voluntary initiation of both imagined and overt action is coupled with respiration, and further suggest that breathing system is involved in preparatory processes of voluntary actions. Beyond this discovery, these findings are of direct relevance for brain-computer interfaces in neuroprosthetics, aiming at rehabilitating motor function and the control of external devices.
References: Park, H.D., Barnoud, C., Trang, H., Kannape, O.A., Schaller, K., Blanke, O., 2020. Breathing is coupled with voluntary action and the cortical readiness potential. Nat. Commun. 11. doi:10.1038/s41467-019-13967-9.