Chapter 6 Study Guide: Learning Ivan Pavlov: A prominent Russian psychologist that first described the process of classical conditioning. He made his discovery while he was studying the role of saliva in the digestive processes of dogs. He was the ?Meat powder ? Ring of Bell ? Salivate? researcher. Classical (Pavlovian) Conditioning: A type of learning in which a stimulus acquires the capacity to evoke a response that was originally evoked by another stimulus (Example: The bell replaces the meat powder as a stimulus for salivating.) [Responses elicited = involuntary] UCS: A stimulus that evokes an unconditioned response without previous conditioning. (Example: Meat Powder)