A/an _________ stimulus naturally does not elicit any response. However, in classical conditioning, it becomes a/an _______ stimulus after being associated with a/an ______ stimulus which does elicit a response.

A stimulus that doesn’t naturally elicit a response is a neutral response.

For example, food is a UCS for dogs and can cause salivation. But ringing a bell by itself doesn’t trigger the same response. The bell’s sound is hence a neutral stimulus