As I read what you wrote Ygrec, the idea of anxiety popped up in my head like Perna has already suggested.

Perhaps it is the silent gap that means some thing to your brother in some way... so then he has to keep talking

Maybe it is something with the fact that he is still here on earth and so why not keep the conversation going

IDK-- but it is good I would think he does talk so, un like on the other side of not talking right