Tracking the Process of Falling Asleep (image) Massachusetts General Hospital Share Print E-Mail Caption Sleep study participants are asked to squeeze a small ball with their hand in time with their breathing, and the force and timing of their motions are measured by the glove and by electrodes on a forearm muscle. By combining EEG brainwave data with information from the way squeezes decrease in frequency and strength as a participant falls asleep, investigators can now track the dynamic changes in brain and body during the sleep onset process. Credit Michael Prerau, PhD, MGH Department of Anesthesia, Critical Care and Pain Management Usage Restrictions None Share Print E-Mail 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.