"Neurophysiologists earlier had discovered that our brain waves show specific signatures of our three major states of consciousness: waking, dreaming, and deep sleep. In materialist neurophysiology, this fact was already hard to explain because no distinction is possible between the conscious and the unconscious. Then came the discovery that the brain wave signature of meditative states is also quite unique, quite distinguishable from the three common states of consciousness (Wallace and Benson 1972). This discovery raised the question, In addition to meditation, are there other distinct states of consciousness aside from the usual three?'
"In spiritual traditions, there is mention of 'higher' states of consciousness called samadhi in Sanskrit. In the Hindu tradition, it is said there are two kinds of samadhi. A transient state of experiencing the 'oneness of everything' is called savikalpa samadhi, samadhi with subject-object split. In Japanese, this state, a state of subject-object split experience, is called satori. More recently, Abraham Maslow called this state the 'peak experience.' Because of its highly transient nature, measuring a brain wave signature for it may be quite challenging.'
"However, Hindus also talk about a second kind of samadhi, called nirvikalpa samadhi, that is, samadhi without subject-object split. This state is therefore more akin to sleep, which also lacks the subject-object split. I call this state 'creative sleep' because in this state consciousness unawarely processes new possibilities, not the old ones of memory processed in regular sleep (Goswami 2008). I suspect that there may very well be a specific neurophysiological signature for creative sleep that can empirically differentiate it from regular deep sleep.'
"The experimental investigation of the higher states of consciousness will open neurophysiology to a broader worldview. The beauty of the new view is, of course, that it does not leave out anything, not even cognitive science."
(pp. 257-8, 'Creative Evolution: A physicist's resolution between Darwinism and Intelligent Design' by Amit Goswami - Wisdom Tree)