It was first suggested that disordered proprioception was a core feature ofschizophrenia by Sandor Rado in 1953. Using a recently designedproprioceptive event-related potential paradigm based on a change of load,we studied 12 unmedicated male out-patients with schizophrenia and 24controls. In the patients, the early contralateral parietal activity wasdelayed and later central activity had increased amplitude, but gating wasunaffected. The results could be understood within the ‘deficiency ofcorollary discharge’ model of schizophrenia but not within the ‘filtering’theory. Further studies, including psychiatric controls, are necessary toverify the specificity of the abnormality.