Final answer:
William Masters and Virginia Johnson were the first researchers to study human sexual response in the laboratory.
Step-by-step explanation:
William Masters and Virginia Johnson were the first researchers to study human sexual response in the laboratory. Their research, published in 1966, involved observing and measuring physiological responses during sexual behavior, including measurements of blood pressure, respiration rate, and sexual arousal. They observed nearly 10,000 sexual acts as part of their study.