EMG recording and resulting time phases. Definition of active, resting and background stages of swallowing-related muscle activity. The EMG recording of one swallowing act is shown (surface electrodes, recording from the submental muscles). To distinguish the swallowing execution phase, each individual's EMG signal was used to mark the swallowing related muscle activation. After an initial increase of more than 50% of EMG activity, the beginning of main muscle activation (M1; 100% increase of activation) and the end of swallowing specific muscle activation (M2; 50% decrease of activation) were marked. To estimate the maximal null distribution a third marker (M0) at the beginning of preparation activity was set and two background phases were defined (see methods section).