I am taking care of my younger brother who has dementia. He’s having conversations with no one in the middle of the night. Is this normal?

Yes, this is normal. Their dreams, TV and reality all blend together. They cannot separate them. As long as he is not scared, I wouldn't worry about it. If he starts getting night terrors where he screams out more than once or twice a week, there is medication for this.

Our Aunt did the same years ago, haldol was prescribed and hallucinations went away. But unfortunately nursing homes have abused the use of antipsychotics, and doctors are reluctant to prescribe them at home anymore at the threat of litigation. We are just leaving lights on all night to reduce symptoms some, and letting our current loved one to go ahead and hallucinate. Nursing homes are still known to over use antipsychotics in order to make patients 'managable', so really not an option unless they become dangerous to themselves.