Question regarding hallucinations

If they were, what would that mean to you?

hallucinations are not limited to past experiences and mental states, so why not?

Because dreams/nightmares are different than hallucinations. They are a distinct neurological state from hallucinations. So that is why I was wondering whether those altered mental states experienced in dreams/nightmares can only be experienced during dreams/nightmares or if they can actually be experienced while awake during a hallucination or a near death experience.

OK, but you started out by defining them as different, so why ask if they can be the same? Maybe I don't understand the question.

Another point: I don't think all dream states are the same. Most are the same but I have have radically different perceptions during a certain few dreams, if that is what they were. 'Normal' dreams soon fade away and nebulous in meaning. The other ones are still clear to me decades later.

I did define them as different. We know that there are different physical processes going on in the brain that differentiates dreams from hallucinations. You have different experiences during hallucinations than dreams.

But I am wondering if it can be the same, too. I am wondering if hallucinations and near death experiences can also bring back those altered mental states we experience in our dreams and nightmares while we are awake.

When a certain experience you had in the past is brought back to you during a hallucination/nde, those same physical processes that gave rise to that experience in the first place are triggered again during the hallucination/nde which is what allows you to have that experience again.

So I am wondering if the physical processes that gave rise to those completely altered mental states I've mentioned during our dreams and nightmares can be triggered again during your waking life during a hallucination/nde. Or if such physical processes can only be possible during the dream state.

There is one physical process that is only possible during the dream state and that would obviously be those processes that make us asleep. But as for the processes that give rise to those altered mental states during our dreams/nightmares, I am wondering if they can be possible during our waking lives during a hallucination/nde.

I dunno. I've only had one nde and it was nothing like any experience or dream I've ever had.

I assume your statements about the physical processes in the brain being different are based on FMRI or EEG studies of the brain. I believe they saw different areas of the brain 'light up' during those events but in my 'amateur brain researcher' opinion, that tool is far to coarse to mean much of anything.

But I see no reason why you could not hallucinate about a dream you had or dream about a past hallucination. Might be hard to slip somebody into the machine at just the right moment to catch it.