Second, the reafference theory fails to explain just how stored efference-reafference correlations are supposed to explain visuomotor control. How does having the ability to anticipate the retinal stimulations that would caused by a certain type of hand movement enable one actually to perform the movement in question? Without elaboration, all that Held’s theory seems to explain is why subjects are surprised when reafferences generated by their movements are non-standard (Rock 1966: 117).