Susupti state of unconsciousness (Hinduism, Zen)

In yoga psychology, among the avasthas (states) is the deep sleep, ego-unconscious condition. According to the Mandukya Upanishad it is the field of Jnana, the cognitional or intellectual condition. It is the state of cessation of thought. In Zen terms, it may said to be consciousness as such, consciousness which is not conscious of anything, even of itself.