"Mama, is that you?" "Where's my daddy?" It can be startling to hear someone with advanced dementia calling out for a parent -- or to confuse a primary caregiver, even a spouse, son, or daughter, for a long-gone figure from the past.
What's happening? What remains of memory tends to be from very early life. It may come out not as whole-cloth stories of the past, as it did earlier in the disease, but in confused snippets. Remembering long-gone parents or other beloved relatives is common because a parent tends to be a security figure. Someone in the depths of disease talking to or about a parent may be feeling sad, uneasy, or anxious.
When you respond:
Don't waste a lot of energy insisting the deceased person being called for isn't alive. Correcting your loved one might only cause unnecessary distress. Better: Say something that sidesteps the issue, such as, "Your mama went out for a minute," or, "I'll be sure to tell him you're looking for him soon as I see him."
Keep the tone reassuring and agreeable.
You may choose to converse about the deceased person, even in the present tense: "Your mama is the prettiest woman I ever saw." "Your daddy works hard, doesn't he?"
Or, say something noncommittal ("You sure are a daddy's girl, aren't you?") and then distract by bringing up a new topic or serving a snack.