actually xtort, the brain doesn't segregate

imagined visual imagery uses the same cortical pathways as actual imagery - save the V1 primary visual cortex that is connected to the eyes. Extensive EEG, MEG, and fMRI testing has shown this. and i woudl say i am conscious when i dream - i can pretty much decide where/what i'm doing.

but i think you have a point xtort.

in naruto world it seems that there are degrees of genjutsu.

also a quick breakdown of the types of genjutsu's used.
orochimaru used paralysis in his jutsu
itachi used pain IN his jutsu

it would be silly if you could scare yourself out of paralysis, wouldn't it?
the same way it would be silly to induce pain to avoid pain.

what orochimaru and tayuya did, shouldn't be compared to itachi's tsukiyomi.
by default itachi's jutsu is on a level of its own - and if you don't know what that default is, i'm gonna slap you.