Measures of apparent motion discrimination ability, memory, and intertrial variability were obtained for groups of 54 normal, 32 neurotic, 54 alcoholic, 54 admission schizophrenic, 108 chronic schizophrenic, and 103 geriatric Ss. The groups differed on all three apparent motion measures, with the greatest impairment manifested by groups with the most severe mental pathology. Low intercorrelations of the apparent motion tasks, differences in correlations with IMPS items, and differences among the groups supported the hypothesis that apparent motion perception and memory processes are independent functions which are impaired to different degrees by different types of mental pathology.
