He now believes his longtime wife is actually his mother. He also believes that his adult son is actually his brother. From reading on the forum, I know these types of things happen with dementia. But, is there any current thinking as to the reason(s) for this? He seems to know certain people belong to him and that's encouraging, but then he can't truly place them. I need some perspective on this. Thanks.
My grandmother would tell my Dad (her son), "I have a son named Jim".
A resident in a LTC facility thought he was on his ship during WWII. Whenever a "Department Meeting" (for heads of nursing, dietary, housekeeping, therapy, etc) was announced over the facility's loud speaker, the resident would go to the meeting because he was a "Department Head" for his section of the battle ship. More than once we had to redirect him to "an urgent problem below deck that required his attention immediately"--he would leave the meeting only if he received permission from "the Commander" (AKA Facility Adminstrator).
That said, you know that this is a common symptom. One idea is to re-introduce oneself to him each time they meet. Stand directly in front of him, be at his eye level, and state who you are and your relationship (wife, son, friend, etc). That may trigger the correct memory of the visitor for him.