Cortical Oscillatory Activity Is Critical for Working Memory as Revealed by Deficits in Early-Onset Schizophrenia
Cortical Oscillatory Activity Is Critical for Working Memory as Revealed by Deficits in Early-Onset Schizophrenia
复制标题
DOI：
10.1523/jneurosci.1428-09.2009
复制
发表时间：
2009-07-29
影响因子：
5.3
通讯作者：
Rodriguez, Eugenio
中科院分区：
文献类型：
--
作者：
Haenschel, Corinna;Bittner, Robert A.;Rodriguez, Eugenio
工作记忆障碍是精神分裂症的核心认知缺陷。神经生理学模型表明，精神分裂症患者WM维持过程中的缺陷可能由gaba能系统的异常来解释，这将导致高频振荡的缺陷。然而，目前尚不清楚三个WM阶段（编码、维持、检索）中哪一个受到功能失调振荡活动的影响。我们采用延迟匹配样本模式，研究了14名早发性精神分裂症患者和14名匹配对照组的宽频率范围（3-100 Hz）振荡活动损伤与WM不同阶段的WM负荷之间的关系。在编码过程中，成功的记忆通过诱发的θ、α和β振荡活动来预测。患者在这些频带的诱发活动表现出严重的减少。在早期WM维持期间，与对照组相比，患者表现出与WM负荷相关的诱导α和γ活性增加。相反，在后期维持阶段，患者表现出诱导γ活动峰值向较低WM负荷条件的转移。最后，患者在检索过程中诱导的θ和γ活动减少。我们的研究结果表明，精神分裂症患者的WM缺陷与任务所有阶段的振荡活动受损有关，并且皮层存储系统在较低负荷时达到其容量极限。因此，无法维持特定频段的振荡活动可能导致信息过载，这可能是精神分裂症认知缺陷和精神病理症状的基础。
Impairments in working memory (WM) are a core cognitive deficit in schizophrenia. Neurophysiological models suggest that deficits during WM maintenance in schizophrenia may be explained by abnormalities in the GABAergic system, which will lead to deficits in high-frequency oscillations. However, it is not yet clear which of the three WM phases (encoding, maintenance, retrieval) are affected by dysfunctional oscillatory activity. We investigated the relationship between impairments in oscillatory activity in a broad frequency range (3-100 Hz) and WM load in the different phases of WM in 14 patients with early-onset schizophrenia and 14 matched control participants using a delayed matching to sample paradigm.During encoding, successful memorization was predicted by evoked theta, alpha, and beta oscillatory activity in controls. Patients showed severe reductions in the evoked activity in these frequency bands. During early WM maintenance, patients showed a comparable WM load-dependent increase in induced alpha and gamma activity to controls. In contrast, during the later maintenance phase, patients showed a shift in the peak of induced gamma activity to the lower WM load conditions. Finally, induced theta and gamma activity were reduced in patients during retrieval.Our findings suggest that the WM deficit in schizophrenia is associated with impaired oscillatory activity during all phases of the task and that the cortical storage system reaches its capacity limit at lower loads. Inability to maintain oscillatory activity in specific frequency bands could thus result in the information overload that may underlie both cognitive deficits and psychopathological symptoms of schizophrenia.