Pupil Size Coupling to Cortical States (VIDEO) Cell Press This video is under embargo. Please login to access this video. Caption This video shows pupil tracking using infrared back-illumination pupillometry (iBip) and corresponding electrocorticogram of a sleeping mouse during periods of NREM, REM, and wakefullness. Credit Özge Yüzgeç, Mario Prsa, Robert Zimmermann, Daniel Huber Usage Restrictions Credit Required. 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.