Currently, I am trying to preprocess an EEG dataset for a research project. The dataset I am working with is CHB-MIT EEG Scalp Dataset (CHB-MIT Scalp EEG Database v1.0.0). Normally the dataset have used 23 channels for recordings however, at the subject named as chb09 they have used one more channel which is VNS. As I searched the Web, I have learned that it is a device used to send signals to the brain but in some articles they mention that it does not have any effects on EEG data recordings (egg: Vagus nerve stimulation has no effect on awake EEG rhythms in humans - PubMed ). Do you know the effect of VNS channel on EEG data recordings and how can it be reduced?
If the VNS channel shows you when the vagus nerve was stimulated, you can use that information to check for yourself. Look at the (raw) data at moments when the nerve is being stimulated: do you see any effect? Next is to cut epochs around the moments of stimulation and compute the evoked response: is there a notable response to the stimulation?
If yes, check out the mne.preprocessing.fix_stim_artifact function.