The role of experience in the process of behavioral refinement has been undertheorized by philosophers of neuroscience and neuroscientists. By examining sleep studies in behavioral neurobiology, I show that scientists frequently invoke a variety of lived experiences—what I call experientially derived notions—to refine the behavior under investigation. Of note, these behaviors must remain sufficiently fuzzy throughout experimentation to permit refinement. The aim of this article is to recognize that neuroscientists’ use of lived experience necessarily helps refine behaviors and render those (...) behavioral terms relevant to human life. (shrink)