EEG Equipment (IMAGE) Wyss Center for Bio and Neuroengineering Caption The glowing lights on this EEG cap signal impedence, an indication of the strength of the electrode-skin contacts. Credit © <a target="_blank"href="http://www.wysscenter.ch/en/home/">Wyss Center</a> Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.