This study assessed the relative ability of 7 field-independent and 8 field-dependent persons to detect changes in rod and frame positions. Each subject received 90 discrimination trials. Each trial consisted of the standard stimulus (both rod and frame tilted 15 degrees to the subject's left) followed by a comparison stimulus (rod or frame differing from the standard by 3 degrees, 6 degrees, 9 degrees, or 12 degrees). Results supported the hypothesized superiority of field-independent persons in detecting frame changes; however, detections of rod changes did not differentiate field-dependent from field-independent persons.