Quarterly Response: Summer 2024

Practitioners who receive our quarterly Mindful Learners Newsletter have the opportunity to submit their questions for Mitchell and Angelika Sadar to answer. To join the mailing list, sign up here.

This month’s question is as follows: Could you please review why it is important to get good impedance? I’ve talked with some providers who say they do not check impedance. Thanks

Response from Dr. Mitchell Sadar:

By getting good impedance we ensure that the quality of the signal getting to the software and being fed back to the brain is as good as we can get it. The lower the electrode impedance the more the EEG data will reflect electrical signals stemming from brain activity underneath the scalp, and the less it can be dominated by other electrical signals of non-interest (e.g., line noise). I think it is obvious that the clearer the signal being used for the training the better the training will be. Hence, ideally we want impedances below 5 kOhms, with below 10k Ohms being acceptable for clinical work. Below 20 kOhms can be acceptable with a patient with whom getting good impedance is difficult and time for training is running out. With impedances above 20 kOhms the balance between the sensors becomes important.