Efficacy of Semantic Cues in Schizophrenic Patients and Patients with Frontal Lesions from the Standpoint of Neuropsychotogical Rehabilitation

摘要

Two neuropsychological studies are presented in which the role of verbal or semantic cues in improving the behavioral deficits of patients with schizophrenia and patients with frontal lesions was investigated. In a study of the efficacy of semantic cues in the performance of the Wisconsin Card Sorting Test (WCST), a new modified version of the WCST, the Keio version (KWCST), was administered to patients with chronic schizophrenia and patients with frontal lesions. Instructions for the KWCST are given in two steps in order to make subsequent task performance easier. In the first step, the instructions are the same as in the original WCST, and in the second step, the patients are instructed that the classification category has been changed. In the first step, patients with schizophrenia and patients with frontal lesions had equally poor results on the KWCST, which suggested frontal dysfunction in patients with schizophrenia. However, marked improvement in the score was observed in the patients with schizophrenia in the second step. The study showed that semantic instructions or cues improved the performance on the WCST more effectively in the patients with schizophrenia. The other study investigated impaired verbal regulation of behavior (IVR) IVR is a relatively well-known frontal lobe symptom, but it has not been studied sufficiently. In normal subjects, speech that expresses an action or that is related to it makes performing the action easier. In patients with frontal lesions, however, the facilitating function of words on actions is frequently lost. The occurrence of IVR was investigated during the tasks of the KWCST in patients with schizophrenia and in patients with frontal lesions. About 70% of the patients with frontal lesions and less than 10% of the patients with schizophrenia had IVR. Both studies suggest that verbal or semantic cues given by oneself and/or others improve behavioral deficits more effectively in patients with schizophrenia than in patients with frontal lesions, and they suggest the importance of verbal or semantic approaches in the effective rehabilitation of schizophrenia.