Is AC recalculated when a character is knocked Unconscious or is Paralyzed due to possible changes to DEX mod?

I recently read a question regarding conditions that generate critical hits. It detailed the Unconscious and the Paralyzed conditions well, but when looking at them, I had the question above.

What happens to the character’s DEX mod when they are Paralyzed or Unconscious? The conditions don’t indicate any changes for this, but both indicate that attacks have advantage, which may cover the lack of dexterity on the part of the victim.

I suspect that I’m suffering from “previous edition-itis” but wanted to check just to be sure.