The work of Barry Sterman, Joel F. Lubar and others has been relevant on the study of beta training, involving the role of sensorimotor rhythmic EEG activity. This training has been used in the treatment of epilepsy, attention deficit disorder and hyperactive disorder. The sensorimotor rhythm (SMR) is rhythmic activity between 12 and 16 hertz that can be recorded from an area near the sensorimotor cortex. SMR is found in waking states and is very similar if not identical to the sleep spindles that are recorded in the second stage of sleep.