When I meditate about the position of events within my experience I find that there are three types or modes of spatial experience. The first is the space of perception, the second is the space of perceptual imagination and the third the space of inner imagination. These spaces are composed of simultaneous events that have an angular displacement at an apparent viewing point.
The spaces overlap one another. Perceptual space directly overlaps imaginary perceptual space. Inner imaginary space is within or almost within the head that appears in my perceptual space and in my imaginary perceptual space. This strongly suggests that all three modes of spatial experience are actually using the same space that I will call the space of experience. The head in this space can contain inner imaginary events, the space beyond the head can contain perceptual imaginary events or perceptions or even both at the same time.
It should be noted that the component of the space of experience that is the distance from the viewing point is almost certainly temporal (see Time and depth).
There is also a mode of spatial experience that occurs when trying to look through closed eyelids when wearing a blindfold, the dark grey/black background of this space is populated by perceptual events in the absolute dark.
It is also probable, although not fully established, that dreams are like imaginary perceptions. It is likely that the space of dreams is also the same space as that of experience in general.
If I view a scene with one eye it appears to contain objects, or more precisely 'events', that occupy different angular positions relative to the eye and other events. As an example, The tree in front of me has another tree about 30 degrees to the left.
If I use one eye and then open a second to observe a view containing objects that are over 5 metres away my entire field of vision expands by about 40 degrees but the more distant objects that were originally within vision scarcely change at all. If I alternate from one eye to the other and then use both it is evident that my centre of vision, the viewing point, shifts to a place between my eyes and possibly behind my forehead. The nearest objects seem to become slightly broader, subtending a greater angle at the centre of vision.
If I am using one eye and attempt to reach out to touch nearby objects in a single motion with my forefinger I can easily miss the objects by a few millimetres. I could easily be fooled about the distance to an object. I scarcely ever miss touching an object when using two eyes.
If I use two eyes some nearby small objects and the edges of nearby large objects become transparent when I look at objects that are further away.
If I look at my desk and shut my eyes I first get a brief afterimage of the desk that fades within perhaps a half second. If I blindfold my eyes I have a black background with faint grey cloudy shapes appearing and disappearing and occasional tiny flashes of light. If I concentrate on looking through my closed eyes the background is a dark grey and appears quite close, possibly a few centimetres in front of my eyes. If I imagine the clock on the wall a rather dull, grey, largely outline, image of the clock appears at the apparent position of the clock. When my eyes are closed the optical sensors provide a nearby background which can be overridden by my imagination into a full imagined view. In the case just described I was first looking at the input from my eyes and then was able to imagine a view with a clock on a wall beyond the input from the eyes. The full imagined view I will call "perceptual imagination".
If have my eyes shut and imagine this computer it appears to be in its normal position relative to me. If I reach out to touch the imagined "space-bar" on the computer keyboard I miss the real space-bar by about a centimetre. My imaginary space overlaps my perceptual space but the objects within these spaces can easily be misaligned. If I imagine the bright white cable on the left of the computer and then open my eyes it is again out of position by about a centimetre. This error is an angular error because when I do the same with a distant object such as a tree the trunk is out of place by about 2-5 degrees which is the same angular error as for the nearby computer cable.
If I stare at a white sheet for about two or three minutes I can imagine a weak image of a green tick on the sheet which confirms the way perceptual space and imaginary perceptual space can overlap. Hallucinogenic drugs greatly enhance this ability to combine imaginary perception with perception in the same space.
If I stare at some patterns and at clouds I can imagine faces or forms, again the imaginary perceptual space overlies perceptual space.
If I have my eyes shut and become discursive, with inner speech dominant, the dark background is contained close to or even within my head, the inner speech being broadly located between my ears and in the lower part of my head towards but above my vocal chords.
When discursive I can imagine objects so that they appear inside my head, for instance I can imagine a silver cross on a black background just behind my eyes and imagine this to move back through my head. The cross is not clearly imaginable when it reaches the viewing point. When I do this it is evident that the viewing point is roughly in the centre of my head, perhaps level with my ears, about 7-9cm behind my eyes. This is roughly the same location as the apparent viewing point for distant objects that is present during binocular vision with my eyes open. This imagined view within my head I will call "inner imagination".
I can imagine the location of colourful scenes, such as that outside my window, in full colour but low resolution even when I am discursive; so the space of inner imagination is indeed just a space within my head within the space of perceptual imagination. The net effect is of being centred in the dark thinking space of my head with imagined objects from the world around and beyond my head being present as bright but blurred images.
When I dream I very occasionally dream of events in or around my bed. Such dreams can be disturbing and when I awake the bed of the dream overlies that of my perception. This suggests that dreams are within imaginary perceptual space.
Higher Meditation might be usefully focused on the boundless "space" that is experience rather than on any of these modes. The spacetime of experience is partly dimensional time and hence unbounded...