Moksha is just an aspect or side-effect of Samadhi or Cosmic Consciousness. It's a release from the death-rebirth cycle, or Samsara.
Rather than focus on various side effects, let's focus on the underlying phenomenon itself, the expansion of awareness that erases the illusions of time, change and diversity.
This phenomenon is has been reported from everywhere in the world. It's been described throughout recorded history by practitioners of every religion -- and no religion. A left temporal seizure appears to reproduce the experience, as do various "entheogenic" or psychedelic drugs -- albeit temporarily.
No religion or guru is required, though certain things like starvation, injury, meditation, &c seem to induce this type of left temporal seizure with some frequency. Samadhi, as I said before, seems to be a neuroelectric or neurochemical phenomenon.
No faith, religion or devotion required.
There is another way to look at these things you raise about brain activities, which to be more specific has to do with fully activating the left amygdala responsible for bliss and love, as opposed to the right amygdala which is fear and aggression. It is seen in seizure patients, but it is not a seizure that is happening. It can happen to anyone, and a seizure may be one of many things that bring on this 'opening'.
Look at it this way, what you see in the brain is a response to the greater underlying perceptual awareness. It is not just an arbitrary event brought on randomly by the brain taking us along for the ride. We already have God-bliss there within us, but it is just not readily accessed because we are distracted in the temporal world of our mind-activities. A peak experience, a God-awareness can open, an Enlightenment experience can happen, Moksha, Kensho, Buddha-mind, Christ-consciousness, etc, in
seemingly random ways. Hence the saying that Enlightenment happens by accident. It hits like a lightning bolt. And when the bolt hits, when that accident happens, it changes ones life. But then we fall back into Samsara. We move back into the world, and the experience of that Oneness moves away from us, it seems.
If Enlightenment happens by accident, meditation makes you accident prone. It puts you in the path of it happening. It doesn't "cause" it. It simply removes the obstacles that prevent it. We learn to allow it to be more and more present and aware in our lives, and as such it transforms us permanently into its image, so to speak. Where religion comes in is relatively simple. The practices create a sense of direction and disciplines that put us in that path. The whole person must be transformed, not just having a state experience of God-bliss. Having an Enlightenment experience is just the beginning, actually towards living an Enlightened life. The experience is the easy part, relatively speaking. Bring all aspects of our lives into accord with it, having them all transformed by it, is what brings us into being an Enlightened being.
Just as meditation puts you in the path of a state experience, moral living, devotion, etc, aligns the whole person on this path to transformation and living free. It brings the body and mind and the spirit into alignment and transformation.
Though we can say we "attain" this, really we already are this. It's all already fully there within us, as is evidenced by these momentary and sudden opening to it. It's nothing we achieve that exists outside of us. It's not attained by the seeking ego to add to itself. It is simply opened to and allowed. Letting go of the seeking mind is the hard part and the effort to make. It is an effort to make no effort. Religion hopefully provides the set of practices and disciplines towards that path.
