We perceive things on the level of vibration they project and hear things on the level of vibration they project.
Sounds, colors, images-
Nothing but perception in our range vibrational coherence.
Of course there's more to it than that,
Such as the amount of light and type of light an object absorbs(or repells for that matter), allows us to see it as a certain color.
But it all boils down to vibration.
^^^Anyone feel free to add or correct anything
What drugs do, is alter the range of our perceptional field.
For example:
There is a theory that proper vibrational stimulation of the pineal gland, at a very specific level, will allow the person to see things that arent there on our level naturally, but do exist on a different plane of existence, ie: a different plane of vibrational frequency.
Drugs primarily work at the pineal gland.
This is why users enter a different state of mind.
There are many theories to explain alien entities.
One theory being, that they exist on a different plane.
Thats how they are able to come and go.
Congratulations.