the world is perceived as still. The reasoning made is that with a passive movement of the eyeball, no efferent copies are made as with active movements that allow sensory changes to be anticipated and controlled for with the result in their absence the world appears to move. Sherrington In 1900, Charles Sherrington, the founder of modern ideas about motor control, rejected von Helmholtz ideas and argued that efference copies were not needed as muscles had their own sense of the movements they made. "The view [of von Helmholtz and his followers] which dispenses with peripheral organs and afferent nerves for the muscular sense has had powerful adherents . . . It supposes that during ... a willed movement the outgoing current of impulses from brain to muscle is accompanied by a 'sensation for innervation'. ... it "remains unproven". This resulted in the idea of efference copies being dropped for the next 75 years. Von Holst In 1950, Erich von Holst and Horst Mittelstaedt investigated how species are able to distinguish between exafference and reafference given a seemingly identical percept of the two. To explore this question, they rotated the head of a fly 180 degrees, effectively reversing the right and left edges of the retina and reversing the subject's subsequent reafferent signals. In this state, self-initiated movements of the fly would result in a perception that the world was also moving, rather than standing still as they would in a normal fly. After rotation of the eyes, the animal showed a reinforcement of the optokinetic response in the same direction as the moving visual input. Von Holst and Mittelstaedt interpreted their findings as evidence that corollary discharge (i.e. neural inhibition with active movement) could not have accounted for this observed change as this would have been expected to inhibit the optokinetic reaction. They concluded that an "Efferenzkopie" of the motor command was responsible for this reaction due to the persistence of the reafferent signal and given the consequent discrepancy between expected and actual sensory signals which reinforced the response rather than preventing it. Sperry The Nobel Prize winner, Roger Wolcott Sperry argued for the basis of corollary discharges following his research upon the optokinetic reflex. He is also regarded as the originator of the term "corollary discharge". Motor adaptation The Coriolis effect Efference copy relates to Coriolis effect in a manner that allows for learning and correction of errors