This is more about the non-verbal aspect of the language.
Essentially, would a nod and a head shake in response to questions like "Ты не спала, да?" or "Ты не ела, да?" mean the same thing? Kind of like "Да, не спала" and "Нет, не спала" as a full response would mean the same thing.
From what I've seen, a head shake is more common (as is the short verbal "нет"), but sometimes I see a nod, which seems... sort of more emotional, maybe? Do those differ in non-verbal communication or am I overthinking it?