Zombie Argument
A philosophical zombie or p-zombie argument is a thought experiment in philosophy of mind that imagines a hypothetical being that is physically identical to and indistinguishable from a normal person but does not have conscious experience, qualia, or sentience. For example, if a philosophical zombie were poked with a sharp object it would not inwardly feel any pain, yet it would outwardly behave exactly as if it did feel pain, including verbally expressing pain. Relatedly, a zombie world is a hypothetical world indistinguishable from our world but in which all beings lack conscious experience.
Sources
Philosophical zombie - Wikipedia