The Triple Rhythm of Brain Waves during Non-REM Deep Sleep (image) Institute for Basic Science Share Print E-Mail Caption The electrical fields of groups of neurons in a certain region of the brain give rise to specific patterns of brain waves. Different areas of the brain generate characteristic squiggles of electroencephalogram (EEG) tracings. Peaks (up-states) represent neurons firing at the same time, while minima (down-states) are the sign of neuronal silence. Depending on the origin, frequency and shape, it is possible to distinguish slow oscillations from the cortex, spindles from the thalamus, and ripples from the hippocampus. Credit IBS, photo modified from Phduet, freepik.com 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.