There is no such thing as a universal self. This would suggest the existence of an objective(universal) perspective. Since we can't share our brain with another brain(mind meld), or see ourselves independent of our senses, a true objective perspective cannot exist. We are trapped within our own subjective reality. There are 5 basic senses(up to 21 total sense organs) we can use to conceptualize our reality. These receptors provide a sensory link, between our brain and the 5 basic elements in Nature(earth, water, air or wind, fire, and space or void). Like most things in life, this link is quality-controlled, and age-sensitive. If our sense organs are degraded, damaged, absent, overwhelmed, or artificially modified, it will alter our perception of reality. Remember, reality itself does not change, but our perception does. Remember also that the brain is the most deceptive organ in the body. It processes our sensory input, and presents us with it's best-guess estimation of our position in space, and how reality appears. Sonar, radar, or an x ray machines will see that same reality differently.
Consciousness is merely a state or level of self-awareness. This state represent only 8% of our total psyche. Over 90% of the bodies metabolism is carried out at the subconscious, and unconscious levels of awareness. The brain is a physical organ that exist within space and time, but the illusion of mind is totally dependent on the activities within a functioning brain. The mind is the dimensionless cognition with zero parameters, and is totally subjective.
There is also no such thing as "ultimate reality", or " transcendent of perceptual reality". Again, this suggest that an ultimate perspective exists, or that we can escape our subjective perspective. Neither is possible. Drugs, meditation, or injuries, can give the illusion transcendence, but our objective reality, and our existence within space and time, are not effected.
The science of Neurophysiology, and Cognitive Psychology have come a long way in their understanding of how the physical brain works.They understand its functions and properties, how it relates to personality and emotions, and how it generates states of consciousness and awareness. In many cases, these activities can even be mimicked artificially. Don