Where is the sensation?

It occurred to me while leaning on my hand in the library and looking at my reflection in the window that I could see my hand on my head. Before that I was concentrating on the feeling of my head at my finger tips, feeling the hair and the scalp and massaging it. It then occurred to me that my mind as it was, positioned at the tips of my fingers, was very much involved with the outside of my skull. Looking at my reflection I then switched to the usual visual experience of the image on the retina that I have long considered before, and my traditional question of whether the visual space is inside or outside the brain. What was different this time as I kept my mind at my finger tips was that clearly my mind was outside my brain because I was experiencing the feeling of the hair on my scalp and that on top of my skull, and that housing my brain.

This is the question: where is the sensation?

It is not so simple as the plain visual question where all space can be reduced to looking out from some central view point. With the mind at the finger tips we are already out-there. Where when we feel something is the in-here. There are no cues of perspective to infer an in-here at all, a homunculus at the centre looking out. The fingers are far away from "me" sitting on my head in the out-there feeling "my" head... how can I feel "my" head I need to be outside "my" head to feel it, but if I am out-side it then whose is it? Very Shurangama but first time I had it so clear.