What is the difference in brainwave activity between those who are aware in these deep states and those who are not?
It has been shown through several EEG studies and experiments that Lucid dreamers, Tibetan monks, Yoga experts etc who maintain a lucid mind in these states that their brains have increased brainwave activity in the 40 hz range which is usually very weak in "normal" people.

In 2009, clinical psychologist Ursula Voss used mild electrical stimuli in a study with 27 young adults who'd never experienced lucid dreaming. The participants slept overnight at the lab. Two minutes after entering the REM (rapid eye movement) stage of sleep which is when dreaming happens, the subjects received weak electrical stimuli to the brain for 30 seconds, or a sham current with no electricity. It was found that when the participants received a frequency between 25-40 hz, 70% (!) of them experienced a lucid dream. These frequencies are in the gamma range and the electrical stimulation done like this increases the corresponding brainwave frequency. After further study they found that the sweet spot was at exactly 40 hz.
Amongst many other studies also, this points to how the 40 hz brainwave activity is key to lucidity as a whole, especially in these deeper Theta/Delta states (meditation/sleep).
Further, Voss had also in another study found that experienced lucid dreamers produced this 40 hz gamma brainwave pattern while lucid dreaming.
This sort of research has inspired me to myself experiment with and create audio tracks to heighten the 40 hz brainwave frequency using audio made to induce these deepest states of awareness in which the normal person is normally asleep.

This 47 minute long audio track uses Blisscoded with added 40 hz isochronic brainwave entrainment.  It's for experimenting/experiencing deep meditation, lucid dreaming, out of body experiences, remote viewing or any other state where you want to be awake in the sleep or meditative state.

Instructions: Preferably lay down while using this. Close your eyes and relax. You'll find yourself starting to drift towards the Theta/Delta state quickly. If you want to extend the session, which is very effective in my experience, once the audio stops you can remove your headphones and drift off to sleep. The higtened level of 40 hz brainwaves helps you remain aware while the body falls asleep. Use whenever you like during the day or before sleeping at night.

Do not use while driving a vehicle or operating any heavy machinery.

Assistance with playing sounds etc here >

People with seizure issues such as epilepsy should never use brainwave audio as it can worsen the condition.