What Does This Channel
Measure?
This channel measures muscular activity of specific facial muscles
(e.g. m. corrugator or zygomaticus) or general tension related muscles
(e.g. neck). High activity of the muscle is reflected in rapidly
oscillating signals of large amplitudes. The raw signal is
highpass-filtered at 10
Hz, rectified, and smoothed with a 16 Hz lowpass filter.
The oscillating signal thus becomes a smoother curve with only positive
values, that can directly be interpreted in terms of amount of muscle
activity.
Editing of EMG Data:
This signal hardly requires any editing. Moreover, artifacts are difficult to separate from normal activity. You can however exlude outliers if you are sure about artifactual epochs and set them to missing values.