Using this apparatus, the participant sits in a darkened room and is instructed to watch a glowing rod surrounded by a square frame, which is also glowing. The experimenter can adjust the tilt of the rod, the frame, and the tilt of the participant’s chair. The participant’s task is to adjust the rod by turning a dial, so that the rod is perfectly upright. To do this accurately, the participant has to ignore cues in the visual field in which the rod appears (i.e., the square frame surrounding the rod, which the experimenter tilts). If the participant adjusts the rod so that it is leaning in the direction of the tilted frame, then that person is said to be dependent on the visual field, or field dependent. Other people disregard the external cues (the frame) and, instead, use information from their bodies in adjusting the rod to upright. Such participants are said to be independent of the field, or field independent