Depression alters "top-down" visual attention: A dynamic causal modeling comparison between depressed and healthy subjects
Depression alters "top-down" visual attention: A dynamic causal modeling comparison between depressed and healthy subjects
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DOI：
10.1016/j.neuroimage.2010.08.061
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发表时间：
2011-01-15
期刊：
影响因子：
5.7
通讯作者：
Phillips, Christophe
中科院分区：
文献类型：
--
作者：
Desseilles, Martin;Schwartz, Sophie;Phillips, Christophe
利用功能磁共振成像(FMRI)，我们最近证明，与匹配的对照组相比，首次出现单相重度抑郁(MDD)的非药物治疗患者表现出对无关视觉信息的异常神经过滤(Desseilles等人，2009)。在扫描过程中，受试者进行视觉注意任务，在注视时施加两种不同水平的注意负荷(低或高)，同时在外围呈现与任务无关的彩色刺激。在本研究中，我们聚焦于视觉注意系统，并在同一数据集上使用动态因果建模(DCM)来评估注意如何影响MDD患者和健康对照组中三个动态相互连接的大脑区域(视觉区域V1和V4以及顶沟(P))的网络。使用贝叶斯模型选择(BMS)和模型空间划分(MSP)来确定每个种群中的最佳模型。对照的最佳模型显示，高注意负荷增加的顶叶活动选择性地与P对V4的负调制有关，这与高注意力减少对无关的有色外周刺激的加工是一致的。解释MDD患者数据的最佳模型显示，低和高注意水平都对P产生调制作用。本研究结果证明，MDD患者视觉注意网络的有效连接异常，这可能是信息注意过滤不足的原因之一。(C)2010 Elsevier Inc.保留所有权利。
Using functional magnetic resonance imaging (fMRI), we recently demonstrated that nonmedicated patients with a first episode of unipolar major depression (MDD) compared to matched controls exhibited an abnormal neural filtering of irrelevant visual information (Desseilles et al., 2009). During scanning, subjects performed a visual attention task imposing two different levels of attentional load at fixation (low or high), while task-irrelevant colored stimuli were presented in the periphery.In the present study, we focused on the visuo-attentional system and used "Dynamic Causal Modeling" (DCM) on the same dataset to assess how attention influences a network of three dynamically-interconnected brain regions (visual areas V1 and V4, and intraparietal sulcus (P), differentially in MDD patients and healthy controls. Bayesian model selection (BMS) and model space partitioning (MSP) were used to determine the best model in each population. The best model for the controls revealed that the increase of parietal activity by high attention load was selectively associated with a negative modulation of P on V4, consistent with high attention reducing the processing of irrelevant colored peripheral stimuli. The best model accounting for the data from the MDD patients showed that both low and high attention levels exerted modulatory effects on P. The present results document abnormal effective connectivity across visuo-attentional networks in MDD, which likely contributes to deficient attentional filtering of information. (C) 2010 Elsevier Inc. All rights reserved.