Modulation of spontaneous fMRI activity in human visual cortex by behavioral state.
Modulation of spontaneous fMRI activity in human visual cortex by behavioral state.
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DOI：
10.1016/j.neuroimage.2008.10.034
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发表时间：
2009-03-01
期刊：
影响因子：
5.7
通讯作者：
Duyn JH
中科院分区：
文献类型：
--
作者：
Bianciardi M;Fukunaga M;van Gelderen P;Horovitz SG;de Zwart JA;Duyn JH
功能磁共振成像的自发活动现象正越来越多地被用于研究人脑功能网络的高空间分辨率连接。虽然越来越多的证据指向神经元对这种活动的贡献，但其功能作用和对行为状态的依赖性仍不清楚。在这项工作中，我们使用BOLD功能磁共振成像在7 T的调制枕区的自发活动的各种行为条件下，包括休息与闭上眼睛，眼睛睁开与视觉固定，眼睛睁开与固定和局部视觉刺激。将自发活动与诱发活动以及与心脏和呼吸周期相关的信号波动分开。我们发现，自发活动在视觉领域大大减少（幅度（44%）和连贯性（25%））与固定条件相对于眼睛关闭的条件。当添加视觉刺激时，没有观察到显著的进一步调制。所观察到的行为条件的依赖性表明，自发的fMRI信号波动的一部分代表神经元的活动。自发活动的调制行为状态的可能机制进行了讨论。所观察到的线性叠加的自发性fMRI活动与局部诱发活动相关的视觉处理功能磁共振成像研究具有重要的意义，理想情况下，应考虑到自发活动的影响，以正确定义在任务条件下的大脑激活。
The phenomenon of spontaneous fMRI activity is increasingly being exploited to investigate the connectivity of functional networks in human brain with high spatial-resolution. Although mounting evidence points towards a neuronal contribution to this activity, its functional role and dependence on behavioral state remain unclear. In this work, we used BOLD fMRI at 7 T to study the modulation of spontaneous activity in occipital areas by various behavioral conditions, including resting with eyes closed, eyes open with visual fixation, and eyes open with fixation and focal visual stimulation. Spontaneous activity was separated from evoked activity and from signal fluctuations related to cardiac and respiratory cycles. We found that spontaneous activity in visual areas was substantially reduced (amplitude (44%) and coherence (25%)) with the fixation conditions relative to the eyes-closed condition. No significant further modulation was observed when the visual stimulus was added. The observed dependence on behavioral condition suggests that part of spontaneous fMRI signal fluctuations represents neuronal activity. Possible mechanisms for the modulation of spontaneous activity by behavioral state are discussed. The observed linear superposition of spontaneous fMRI activity with focal evoked activity related to visual processing has important implications for fMRI studies, which ideally should take into account the effect of spontaneous activity to properly define brain activations during task conditions.
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影响因子：
5.7
作者：
Gonçalves, SI;de Munck, JC;da Silva, FHL
通讯作者：
da Silva, FHL
影响因子：
2.5
作者：
Fukunaga, Masaki;Horovitz, Silvina G.;Duyn, Jeff H.
通讯作者：
Duyn, Jeff H.
影响因子：
4.8
作者：
Hampson, M;Peterson, BS;Gore, JC
通讯作者：
Gore, JC
DOI：
10.1073/pnas.0308627101
发表时间：
2004-03-30
影响因子：
11.1
作者：
Greicius, MD;Srivastava, G;Menon, V
通讯作者：
Menon, V
影响因子：
2.5
作者：
Feige, B;Scheffler, K;Seifritz, E
通讯作者：
Seifritz, E