Inefficient Preparatory fMRI-BOLD Network Activations Predict Working Memory Dysfunctions in Patients with Schizophrenia.
Inefficient Preparatory fMRI-BOLD Network Activations Predict Working Memory Dysfunctions in Patients with Schizophrenia.
复制标题
DOI：
10.3389/fpsyt.2016.00029
复制
发表时间：
2016
影响因子：
4.7
通讯作者：
Koenig T
中科院分区：
文献类型：
--
作者：
Baenninger A;Diaz Hernandez L;Rieger K;Ford JM;Kottlow M;Koenig T
精神分裂症患者在使用功能性磁共振成像（fMRI）评估时，显示出时间相干网络（TCNs）的动态和结构异常，这些网络在为一项对认知要求较高的任务做准备时会发生适应性变化。在工作记忆（WM）任务期间，精神分裂症患者在TCNs以及工作记忆的脑电图（EEG）指标方面均表现出持续的缺陷。研究它们在工作记忆任务期间的时间关系可能会为精神分裂症中所见的工作记忆表现缺陷提供新的见解。在17名精神分裂症患者和17名匹配的健康对照者执行具有两种负荷水平（负荷2和负荷5）的言语斯特恩伯格工作记忆任务期间，获取了同步的脑电图 - 功能性磁共振成像数据。通过协方差映射，我们研究了在记忆项目编码之前TCNs中的活动与保持间隔期间脑电图频谱功率之间的关系。我们评估了四个TCNs——默认模式网络（DMN）、背侧注意网络（dAN）、左右工作记忆网络（WMNs）——以及三个脑电图频段——θ波、α波和β波。在健康对照组中，DMN与额中线θ波功率之间存在负荷依赖的反向关系，并且DMN与dAN之间存在反相关。在患者中，这两种效应均未显著检测到。此外，健康对照组显示出WMNs的左侧化负荷依赖的募集。患者中WMNs的激活是双侧的，这表明为了在工作记忆任务上成功表现而募集了更多资源。我们的研究结果支持这样一种观点，即精神分裂症患者在言语工作记忆任务中相关信息保持之前，其神经生理反应出现偏差。因此，针对预状态的神经反馈等治疗策略可能是有益的，因为任务表现依赖于大脑的准备状态。
Patients with schizophrenia show abnormal dynamics and structure of temporally coherent networks (TCNs) assessed using fMRI, which undergo adaptive shifts in preparation for a cognitively demanding task. During working memory (WM) tasks, patients with schizophrenia show persistent deficits in TCNs as well as EEG indices of WM. Studying their temporal relationship during WM tasks might provide novel insights into WM performance deficits seen in schizophrenia. Simultaneous EEG-fMRI data were acquired during the performance of a verbal Sternberg WM task with two load levels (load 2 and load 5) in 17 patients with schizophrenia and 17 matched healthy controls. Using covariance mapping, we investigated the relationship of the activity in the TCNs before the memoranda were encoded and EEG spectral power during the retention interval. We assessed four TCNs – default mode network (DMN), dorsal attention network (dAN), left and right working memory networks (WMNs) – and three EEG bands – theta, alpha, and beta. In healthy controls, there was a load-dependent inverse relation between DMN and frontal midline theta power and an anti-correlation between DMN and dAN. Both effects were not significantly detectable in patients. In addition, healthy controls showed a left-lateralized load-dependent recruitment of the WMNs. Activation of the WMNs was bilateral in patients, suggesting more resources were recruited for successful performance on the WM task. Our findings support the notion of schizophrenia patients showing deviations in their neurophysiological responses before the retention of relevant information in a verbal WM task. Thus, treatment strategies as neurofeedback targeting prestates could be beneficial as task performance relies on the preparatory state of the brain.