ABSTRACT
B. Ritzler (J. Abnorm. Psychol., 86: 501-504, 1977) failed to replicate previous weight-lifting studies showing a proprioceptive deficit in schizophrenics. However, Ritzler did not use the same standard weights that the previous studies employed. Could this difference in procedure have caused his failure to replicate? Two experiments were completed to provide additional information about this question and related issues. In Experiment I, chronic hospitalized schizophrenics and normals were tested with light and heavy weights. Rosenbaum's original modified method of limits and the method of constant stimuli were utilized. Both methods provided comparable results, which, like Ritzler's data, failed to show a differential impairment in the discrimination of the light weights for paranoid schizophrenics. In Experiment II, outpatient paranoid schizophrenics, outpatient nonparanoid schizophrenics, outpatient psychiatric patients, and aged normals were evaluated utilizing the same psychophysical procedure and standard weights employed in the original studies. No differential impairment was found for the light weights for any group. These results provide strong support for Ritzler's position that a proprioceptive deficit is not unique to schizophrenia.
