Spontaneous neuronal activity distinguishes human dorsal and ventral attention systems
Spontaneous neuronal activity distinguishes human dorsal and ventral attention systems
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DOI：
10.1073/pnas.0604187103
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发表时间：
2006-06-27
影响因子：
11.1
通讯作者：
Raichle, Marcus E.
中科院分区：
文献类型：
--
作者：
Fox, Michael D.;Corbetta, Maurizio;Raichle, Marcus E.
在对正常受试者的任务相关成像研究的基础上，研究人员认为人脑中存在两个注意系统：一个是双侧背侧注意系统，负责自上而下的注意定向；另一个是右侧腹侧注意系统，负责对显著感觉刺激进行注意重定向。一个重要的问题是，这种功能组织是否只出现在对外部注意力需求的反应中，还是在大脑活动的内部动态中更基本地表现出来。为了解决这个问题，我们研究了在没有任务、刺激或明确注意要求的情况下，功能性MRI血氧水平依赖信号自发波动的相关性。我们在自发活动的基础上确定了双侧背侧注意系统和右侧腹侧注意系统。此外，我们观察到前额皮质区域与这两个系统相关，这是调节系统之间功能相互作用的潜在机制。这些发现表明，在没有外部事件的情况下，人类注意力的神经解剖学基础仍然存在，反映在自发活动的相关结构中。
On the basis of task-related imaging studies in normal human subjects, it has been suggested that two attention systems exist in the human brain: a bilateral dorsal attention system involved in top-down orienting of attention and a right-lateralized ventral attention system involved in reorienting attention in response to salient sensory stimuli. An important question is whether this functional organization emerges only in response to external attentional demands or is represented more fundamentally in the internal dynamics of brain activity. To address this question, we examine correlations in spontaneous fluctuations of the functional MRI blood oxygen level-dependent signal in the absence of task, stimuli, or explicit attentional demands. We identify a bilateral dorsal attention system and a right-lateralized ventral attention system solely on the basis of spontaneous activity. Further, we observe regions in the prefrontal cortex correlated with both systems, a potential mechanism for mediating the functional interaction between systems. These findings demonstrate that the neuroanatomical substrates of human attention persist in the absence of external events, reflected in the correlation structure of spontaneous activity.