The introduction of digital games and simulations into science museums has prompted excitement about a new "post-museum" pedagogy emphasizing egalitarianism, interactivity, and personalized approaches to learning. However, many post-museums of science, this article aims to show, enact rhetorical performances that lead visitors to narrowly targeted answers and hide the authority of the expert in a play of tactile and affective activities, thus operating in opposition to many of the basic ideals of the post-museum. The Brain and Cognition Exhibit at the Hong Kong Science Museum serves as a case study for how a post-museum exhibit, through embracing interactivity and visitor-centered tasks, becomes a site where science is tested on and performed through visitors' bodies such that institutional prescriptions are applied. Visitors are not merely encouraged at this exhibit to learn about the brain through doing but are trained to see functional and dysfunctional brains and to then diagnose themselves and their children by playing games and taking brain-measurement tests. As a result, the interactive engagement of the exhibit creates a new space of public medicalization. Reflections and suggestions are offered at the end of the article.