Third, adaptation to ORDs, contrary to the theory, is not restricted to situations in which subjects receive reafferent visual feedback, but may also take place when subjects receive feedback generated by passive effector or whole-body movement (Singer &amp; Day 1966; Templeton et al. 1966; Fishkin 1969). Adaptation is even possible in the complete absence of motor action (Howard et al. 1965; Kravitz &amp; Wallach 1966).