Complex sentence: His handlers used operant conditioning with positive reinforcement to associate pom-poms with a carrot treat; he soon would turn to his handlers and look for a treat whenever he saw a cheerleader with pom-poms.
Split into simpler sentences: His handlers used operant conditioning with positive reinforcement, associating pom-poms with a carrot treat. Eventually, he began turning to his handlers anticipating a treat whenever he saw a cheerleader with pom-poms.