in the late nineteenth century, who experimented on dogs to evaluate their “conditioned” responses, like salivation?

In the late nineteenth century, the scientist who experimented on dogs to evaluate their "conditioned" responses such as salivation was Ivan Pavlov. He conducted systematic research on dogs' salivation in response to stimuli like the sound of a bell, which he used to condition the dogs to associate the sound with food, leading to salivation even without food present. This discovery became known as classical conditioning or Pavlovian conditioning and is foundational in the study of learned behaviors and reflexes.