Preattentive information processing was examined in matched samples of process nonparanoid schizophrenics, reactive paranoid schizophrenics, and nonschizophrenic psychiatric inpatients. Three measures of visual preattentive processing were administered under standard conditions and also enriched conditions in which preattentive discriminability was enhanced through increased perceptual grouping and segregation. Nonparanoid schizophrenics displayed a differential performance deficit under standard conditions on each measure. Under conditions of enhanced preattentive discriminability, nonparanoid schizophrenics differentially improved to the extent that no significant differences were found between groups on two of the measures. Paranoid schizophrenics and psychiatric controls did not differ significantly across measures or conditions.