Figure 1. BSSS (aka BETS) on ipsilateral ear reference (left) and longitudinal bipolar montage (right). Note steep descending slope of low-amplitude spike and small after-coming slow wave, particularly at T7 to TP11. BSSS are a common feature in adult EEGs during drowsiness and sleep. Note the typical steep descending waveform limb and lack of background disturbance. Copyright ©2016 by American Epilepsy Society. Copyright of all cited figures: Copyright ©2016 by American Epilepsy Society. No permission is required from the editors, authors, or publisher to reuse or repurpose content, provided the original work is properly cited. Figures, tables, and images included in a publication of “Electroencephalography (EEG): An Introductory Text and Atlas of Normal and Abnormal Findings in Adults, Children, and Infants” are also published under the CC BY-NC-SA license and should be properly cited when reused or repurposed.