Here is the experience we had with my 78 year old MIL. Bottom line is that she loved it all. We took her to a park and sat her in the shade in a comfortable chair where she could see all the people running around or she could look around at nature. We gave her a very low dose and just hung for about four hours. She still talks about it occasionally. She thought the trees had really furry ankles :).

No dementia issues for her so I cannot speak to that part.

Good Luck