I have some experience with this.

Best approach I have used, seen, and heard about is conversation about pictures. Viewing the pictures themselves can have the result of sending a person further into an isolated and/or stupefied worldview. It's the interaction about the pix-- family pix of colorful magazine pix-- that do the trick.

If you can't be there to do that, phone calls about printed pix that can be handled during conversation might work. Home visits from local volunteer agencies can sometimes be arranged.

And what is workably helpful abot pix-conversation has nothing to do with "right" answers and everything to do with responding to ANY answer offered, to elicit more memory, more replies. If one persists despite the nonsense one thinks one is getting, very often a breakthrough either in one's understanding or in the actual answering abilities of the elder can happen and can be sustained for long stretchs of lucidity. What they like is talking, and being heard, and responding back and forth no matter what the "content."

~S~