to perform the rod and frame task, an apparatus consisting of a rod in a square frame is used. an example commercial apparatus can be seen in picture 1. when the participant is being tested using the apparatus, their head is fastened firmly in the chin rest to prevent the participant from collecting visual cues from outside of the apparatus. the rod and frame are shown in the center of the far end of the apparatus, which provides a frame of reference to the participant. both the participant and the experimenter are able to adjust the orientation of the rod, while only the experimenter can adjust the frame orientation by using the appropriate knobs on the apparatus, as seen in picture 2. the experimenter is able to see the exact degree measurement of the rod and frame from vertical, while the participant sees the physical rod and frame inside the apparatus.