Stimulus sequence affects schizophrenia - normal differences in event processing during an auditory oddball task
Stimulus sequence affects schizophrenia - normal differences in event processing during an auditory oddball task
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DOI：
10.1016/j.cogbrainres.2005.01.020
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发表时间：
2005-07-01
期刊：
影响因子：
--
通讯作者：
Buckley, PF
中科院分区：
文献类型：
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作者：
Gilmore, CS;Clementz, BA;Buckley, PF
精神分裂症患者难以区分相关和无关的听觉信息。听觉怪异范式通常被用来研究刺激相关性的加工。本研究使用密集阵列脑电和分布式源重建来检验精神分裂症-正常人在目标和标准加工过程中的差异，作为刺激时间序列的函数。分别评估早期和晚期标准(分别遵循目标的标准1-3和4-6)和早期和晚期目标(分别遵循2-3标准和4-6标准)的大脑反应。精神分裂症患者事件相关电位(ERP)波峰(N1、P2、P3)潜伏期与正常人无差异。然而，精神分裂症-神经活动的正常差异，由最小范数估计得出，在刺激处理过程中的特定时间发生，作为刺激序列的函数。精神分裂症患者在对晚期靶点的早期事件相关电位(左半球N1，右侧额叶P2)中表现出比正常人更小的活动，并且他们对晚期标准产生类似P3的反应。此外，在P2/N2时间间隔内，精神分裂症患者和正常受试者对标准反应的大脑活动模式相反，这表明对相同刺激事件的神经反应不同。这些结果表明，精神分裂症患者的注意力分配到与任务无关的刺激上，结果是对刺激意义和背景的表征不充分。因此，精神分裂症损害了恰当地利用语境解决哪怕是简单认知问题的能力。(C)2005 Elsevier B.V.保留所有权利。
Schizophrenia patients have difficulty distinguishing relevant from irrelevant auditory information. Auditory oddball paradigms are commonly used to investigate the processing of stimulus relevance. The present study used dense-array EEG and distributed source reconstructions to examine schizophrenia-normal differences in the processing of targets and standards as a function of the temporal sequence of stimuli. Brain responses were evaluated separately for early and late standards (standards 1-3 and 4-6 following a target, respectively) and early and late targets (those following 2-3 standards and 4-6 standards, respectively). The latencies of peaks (N1, P2, P3) in the event-related potential (ERP) waveforms did not differ between schizophrenia and normal subjects. However, schizophrenia-normal differences in neural activity, derived from minimum norm estimation, occurred at specific times during stimulus processing as a function of stimulus sequence. Schizophrenia patients displayed smaller activity than normals in early ERPs (left hemispheric N1, right frontal P2) to late targets, and they produced P3-like responses to late standards. Furthermore, during the P2/N2 time interval, opposite patterns of brain activity were elicited in schizophrenia and normal subjects in response to standards, indicating different neural responses to the same stimulus events. These results suggest attention allocation to task-irrelevant stimuli in schizophrenia, consequent upon insufficient representation of stimulus significance and context. Thus, schizophrenia compromises the ability to properly use context to solve even simple cognitive problems. (c) 2005 Elsevier B.V. All rights reserved.