Kim Junghoon, Glahn David C, Nuechterlein Keith H, Cannon Tyrone D
Department of Psychology, University of California, Los Angeles, 1285 Franz Hall, Box 951563, Los Angeles, CA 90095-1563, USA.
Schizophr Res. 2004 Jun 1;68(2-3):173-87. doi: 10.1016/S0920-9964(03)00150-6.
Impairments in working memory (WM) have been proposed to underlie various cognitive and functional impairments in schizophrenia. However, the nature and extent of the dysfunction remain unclear. The present study attempted to examine the integrity of sub-components of working memory in schizophrenia within the framework of the multiple-component working memory model proposed by Baddeley. Two sets of visuospatial and verbal delayed-response tasks were developed which had comparable formats and difficulties across domains. In Experiment 1, demands on the central executive (CE) were manipulated by requiring subjects either (1) to simultaneously maintain and transform information (maintenance-and-manipulation condition) or (2) just to maintain this information (maintenance-only condition). In Experiment 2, the amount of information to be maintained over the delay was parametrically varied to evaluate demands on the temporary maintenance component of working memory. Patients (N=16) performed worse than controls (N=16) in both conditions of Experiment 1; however, simultaneous maintenance and manipulation was associated with a significantly greater performance reduction in the patients. In Experiment 2, both patients (N=15) and controls (N=15) declined in performance, at equivalent rates, with increasing memory load. Parallel findings were observed for the verbal and visuospatial tasks. These results suggest that while both maintenance and central executive aspects of working memory are impaired in schizophrenic patients, the central executive may be more severely affected.
工作记忆（WM）受损被认为是精神分裂症各种认知和功能障碍的潜在原因。然而，功能障碍的性质和程度仍不清楚。本研究试图在Baddeley提出的多成分工作记忆模型框架内，检验精神分裂症患者工作记忆子成分的完整性。开发了两组视觉空间和言语延迟反应任务，它们在不同领域具有可比的形式和难度。在实验1中，通过要求受试者（1）同时保持和转换信息（保持与操作条件）或（2）仅保持此信息（仅保持条件）来操纵对中央执行系统（CE）的需求。在实验2中，延迟期间要保持的信息量被参数化地改变，以评估对工作记忆临时保持成分的需求。在实验1的两种条件下，患者（N = 16）的表现均比对照组（N = 16）差；然而，同时进行保持和操作时，患者的表现下降幅度明显更大。在实验2中，随着记忆负荷增加，患者（N = 15）和对照组（N = 15）的表现均以相同的速率下降。在言语和视觉空间任务中观察到了类似的结果。这些结果表明，虽然精神分裂症患者的工作记忆保持和中央执行方面均受损，但中央执行系统可能受到更严重的影响。
