‘Perceptual theories—direct, indirect, and computational’ considers three different conceptions of what it means to perceive and the processes involved in each theory. The origins of indirect or constructivist theory can be traced back to Hermann von Helmholtz in the 19th century, who emphasized the importance of experience in shaping our perceptual abilities. It was assumed that the primary purpose of perception was to create subjective experiences. The American psychologist James Gibson first suggested a direct theory—that the primary role of perceptual processes was to guide action. Since the 1960s, there have been many attempts to model the perceptual processes using computer algorithms, with David Marr at MIT being the most influential figure.