The area of entertainment has typically had a lower priority in BCI work, compared to more “functional” activities such as basic communication or control tasks. For the purposes of this survey, entertainment encompasses everything from video games, to interaction with collections of media to control of ambient features, such as wall displays, lighting, and music. In tasks such as music or images, the feedback from even a “wrong” selection is usually pleasant (assuming the user likes the music or images in their collection), and interaction techniques can be focused on more exploratory approaches to browsing collections. This is sometimes called hedonic interaction in distinction from utilitarian interaction, and it leads to a need for a more broad set of metrics for evaluation of user experience. In this context, a BCI will facilitate activities such as browsing digital photo collections or music collections, where the control might be at the level of specifying a mood or genre. Such systems might also provide opportunities for users to express their emotional state, or desires to a caregiver more rapidly and expressively than using written language.