Sensing the Human Alpha Rhythm Using a Non-Contact Electroencephalographic Electrode

The EEG is typically recorded using wet electrodes that make ohmic contact with the scalp surface using an electrolytic gel. Unfortunately, wet electrodes are intrusive to the user, problematic for EEG studies requiring high spatial resolution, and are unsuitable for long-duration EEG recordings. This paper summarizes preliminary results on measuring the EEG at room temperature, through hair, without scalp contact using a high-impedance active electrode. Preliminary tests focus on detection of the alpha rhythm with a differential, non-contact measurement at O1 and O2, 3.5 mm from the scalp.