Lawrence V A, Doughty O, Al-Mousawi A, Clegg F, Done D J
Department of Psychology, University of Hertfordshire, Hatfield, Hertfordshire, AL10 9AB, UK.
Schizophr Res. 2007 Aug;94(1-3):172-9. doi: 10.1016/j.schres.2007.04.012. Epub 2007 Jun 12.
Semantic memory impairments have been reported extensively in people with schizophrenia. Inefficient search and retrieval strategies, due to an executive dysfunction, rather than a primary loss of semantic knowledge are a primary candidate for such impairments. In order to test this hypothesis we compared the performance of 20 patients meeting DSM-IV-TR criteria for schizophrenia with that of 20 healthy controls and 10 patients with acquired brain injury (ABI) with a dysexecutive syndrome. Seventy percent of the people with schizophrenia and 100% of the ABI patients in this study met criteria for executive impairment. However, the two groups performed significantly differently on a range of semantic memory tests. Whereas 45% of the patients with schizophrenia met criteria for distorted semantic category boundaries (n.b. overinclusion), this was true for only 10% of the ABI patients. In addition, no correlation was found between severity of executive dysfunction and tendency to overinclude in the schizophrenia group. This pattern of neuropsychological findings suggests that overinclusion, or disorganized semantic categorization procedures, in schizophrenia does not result from a classical executive dysfunction. Alternative explanations are discussed.
语义记忆障碍在精神分裂症患者中已有广泛报道。由于执行功能障碍导致的低效搜索和检索策略，而非语义知识的原发性丧失，是此类障碍的主要候选原因。为了验证这一假设，我们将20名符合DSM-IV-TR精神分裂症标准的患者与20名健康对照者以及10名患有执行功能障碍综合征的后天性脑损伤（ABI）患者的表现进行了比较。在本研究中，70%的精神分裂症患者和100%的ABI患者符合执行功能障碍标准。然而，两组在一系列语义记忆测试中的表现存在显著差异。45%的精神分裂症患者符合语义类别边界扭曲（即过度包容）的标准，而ABI患者中只有10%符合这一标准。此外，在精神分裂症组中，未发现执行功能障碍的严重程度与过度包容倾向之间存在相关性。这种神经心理学研究结果模式表明，精神分裂症中的过度包容或语义分类程序紊乱并非由典型的执行功能障碍导致。文中讨论了其他解释。
