Interactive media is related to the concepts interaction design, new media, interactivity, human computer interaction, cyberculture, digital culture, interactive design, and can include augmented reality and virtual reality. An essential feature of interactivity is that it is mutual: user and machine each take an active role (see interaction). Most interactive computing systems are for some human purpose and interact with humans in human contexts. Manovich complains that 'In relation to computer-based media, the concept of interactivity is a tautology. .... Therefore, to call computer media “interactive” is meaningless – it simply means stating the most basic fact about computers.'. Nevertheless, the term is useful to denote an identifiable body of practices and technologies. Interactive media are an instance of a computational method influenced by the sciences of cybernetics, autopoiesis and system theories, and challenging notions of reason and cognition, perception and memory, emotions and affection.