Working memory related gamma oscillations in schizophrenia patients
Working memory related gamma oscillations in schizophrenia patients
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DOI：
10.1016/j.ijpsycho.2006.07.007
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发表时间：
2007-04-01
影响因子：
3
通讯作者：
Schmiedt, Christina
中科院分区：
文献类型：
--
作者：
Basar-Eroglu, Canan;Brand, Andreas;Schmiedt, Christina
最近的报告显示，精神分裂症患者大脑中支持高频同步的神经网络的能力降低。具体而言，缺陷的γ活动已被证明在精神分裂症患者在知觉和简单的认知任务。然而，很少有人知道在复杂和更高的认知过程中的伽马反应的变化。本研究的主要目的是探讨精神分裂症患者（N=10）和健康对照组（N = 10）在不同工作记忆（WM）负荷的任务中事件相关伽马反应的调制。伽马振幅值获得了一个简单的选择反应任务，一个低WM需求的任务，和一个高WM需求的任务。在所有三个任务中，精神分裂症患者的反应时间显着较慢，错误率高于对照组。刺激开始后γ振幅的逐渐增加与对照组WM负荷的增加有关。相比之下，无论患者的任务难度如何，高振幅伽马振荡都保持不变。这些结果表明，健康受试者根据任务难度使用各种认知策略，而精神分裂症患者需要启动复杂的认知过程，类似于在处理新的背景或刺激，即使是简单的选择反应任务，认知需求低。(c)2006 Elsevier B.V.保留所有权利。
Recent reports show that the capability of neural networks supporting high-frequency synchronization is reduced in the brain of schizophrenia patients. Specifically, deficits in gamma activity have been shown in schizophrenia patients during perception and simple cognitive tasks. However little is known about alterations in gamma responses during complex and higher cognitive processing. The main objective of this study was to investigate modulation of event-related gamma responses in tasks varying working memory (WM) load in schizophrenia patients (N=10) and healthy controls (N=10). Gamma amplitude values were obtained for a simple choice reaction task, a low WM demand task, and a high WM demand task. During all three tasks schizophrenia patients showed significantly slower reaction times and higher error rates than controls. A gradual increase of gamma amplitudes after stimulus onset was associated with increase of WM load in controls. In contrast, high amplitude gamma oscillations remained constant regardless of task difficulty in patients. These results suggest that healthy subjects used various cognitive strategies depending on task difficulty, while schizophrenia patients needed to initiate complex cognitive processes similar to those used during processing of novel contexts or stimuli even for the simple choice reaction task with low cognitive demand. (c) 2006 Elsevier B.V. All rights reserved.