Affective memory and schizophrenic anhedonia

Two experiments attempted to isolate and measure schizophrenic anhedonia as it is reflected in the mnemonic processing of affectively laden stimuli. In the first experiment, subjects were required to sort a list of words repeatedly, each in terms of pleasantness, until a consistent sorting was achieved. Then, they were unexpectedly asked to recall the list. Schizophrenics' total recall was comparable to that of normals; but while normals recalled significantly more pleasant than unpleasant words (a Pollyanna tendency), such differential recall was absent in schizophrenics (anhedonia). These results were complicated, however, by the intrusion of semantic variables into the affective processing. In the second experiment, human faces were used to minimize semantic intrusions. Subjects were induced to encode photographs of faces in the context of favorable-unfavorable personality traits, and their recognition memory for these faces was subsequently tested. In spite of comparable overall performance, normals recognized significantly more favorably than unfavorably encoded faces, and such asymmetric recognition was absent in schizophrenics. Furthermore, a significant Group by Affect interaction emerged. The results were taken as evidence of schizophrenic anhedonia and normals' Pollyanna tendency. Nonschizophrenics also served as controls but their results were equivocal. Several problems which may be typical in the experimental investigation of affect were discussed.