Stroboscopic motion is the effect wherein a person perceives a rapid series of images as one continuous moving image. This is demonstrated in television and film, where around 30 images are flashed on-screen per second. Since the images themselves are not moving, it is the brain that interprets these images as continuous and therefore adds the illusion of motion. The idea that the brain tends to perceive the whole image rather than the individual parts of it is called the gestalt theory.