I am a counselor for the elderly with dementia. This reminds me of an exercise that the local Council on Aging gave my co-workers and me. They put you in a room, with strobing lights. You are equipped with goggles smeared with Vaseline, headphones that play noise, shoes with prickles that emulate neuropathy. You had to do some chores in the dark, strange room, and that this was what Alzheimer's was like. I fumbled in frustration, a coworker sat on the floor, a coworker ran from the room crying. It is a truly horrifying experience.
Please, love your Alzheimer's family member. They may not remember you, but emotional connections are some of the last things that leave. They will remember your love.