Delta is generated in dipoles within sheets of cortical tissues. Delta arises from unmyelinated white matter in early life, as well as in deep dreamless sleep, when pacemakers in thalamic and septo-hippocampal, hypothalamic, and brainstem locations create the slow pulsing carrier wave rhythms of the EEG by activating large groups of synchronous neurons at the same time.. Early in life delta is created by the fundamental neuronal structures of the reptilian system and delta appears during the initial migration of neurons across the lobe of the brain, as they form the basic networks of the brain that make up the fundamental architecture from which everything else springs forth.