Another related source of information for adaptation derives from the conflict between seen and proprioceptively experienced limb position (Wallach 1968; Ularik &amp; Canon 1971). When this discrepancy is made conspicuous, proponents of the information hypothesis have found that passively moved (Melamed et al. 1973), involuntarily moved (Mather &amp; Lackner 1975), and even immobile subjects (Kravitz &amp; Wallach 1966) exhibit significant adaption. Although self-produced bodily movement is not necessary for adaptation to occur, it provides subjects with especially salient information about the discrepancy between sight and touch (Moulden 1971): subjects are able proprioceptively to determine the location of a moving limb much more accurately than a stationary or passively moved limb. It is the enhancement of the visual-proprioceptive conflict rather than reafferent visual stimulation, on this interpretation, that explains why active movement yields more adaptation than passive movement in Held’s experiments.