Waking, Being, Dreaming, chapter eight continued

Continuing from this post:

Neurologically, in deep sleep brain waves slow down into the delta range. Large-scale brain integration and synchrony shuts down. Such integration is necessary for access consciousness but apparently not so for phenomenal consciousness, which is what meditative traditions presume is happening in deep sleep. Said traditions also claim that through such training one indeed can access the phenomenal consciousness of deep sleep.

However in Vedanta consciousness in deep sleep is causal, i.e., a metaphysical notion of it as the foundation for the entirety of reality as such. Thompson naturalizes this state as causal in the sense that some neuroscientists see it as a default mode of consciousness. I'm reminded of tonic attention from this post in the states thread, it too being without content. It's a natural state due to (caused) our embodiment, not some transcendent, metaphysical cause. We see more of the metaphysical slant with Tibetan sleep yoga, which sees this state as pure awareness. Yes, it may be an ancient, causal, ground brain state of awareness for other and newer brain states, but again it's quite a leap to the cause of ultimate reality as it seems to phenomenal experience.

Recall earlier it was noted that deep sleep lacks large-scale integration. However to date there are no neuroscience studies on whether such meditative training provides that sort large-scale brain integration necessary for access consciousness. Long-term meditators did exhibit some gamma activity in a part of the brain, but it was isolated to this part whereas other parts did not exhibit these waves. Large-scale brain integration it was not.