Baseline brain activity fluctuations predict somatosensory perception in humans
Baseline brain activity fluctuations predict somatosensory perception in humans
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DOI：
10.1073/pnas.0611404104
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发表时间：
2007-07-17
影响因子：
11.1
通讯作者：
Laureys, S.
中科院分区：
文献类型：
--
作者：
Boly, M.;Balteau, E.;Laureys, S.
在感知实验中，在同一刺激的多次呈现中观察到个体内部感知的波动，这种现象仍然只有部分被理解。在这里，通过铥钇/铝石榴石激光和事件相关的功能磁共振成像，我们测试了相同刺激感知的变异是否与刺激前、基线大脑活动的差异有关。结果表明，低强度体感刺激的意识感知分别与内侧丘脑和外侧额顶叶网络的基线活动水平呈正相关，这被认为与警惕性和“外部监测”有关。相反，随后的意识知觉报告和包括后扣带回/楔前叶和颞顶叶皮质的一组区域的基线活动之间存在负相关，可能与内省和自我导向过程有关。在伤害性刺激水平下，疼痛强度评级与前扣带皮层（已知涉及疼痛情感维度的区域）的基线波动呈正相关。这些结果表明，基线大脑活动波动可能会深刻改变我们对外部世界的意识感知。
In perceptual experiments, within-individual fluctuations in perception are observed across multiple presentations of the same stimuli, a phenomenon that remains only partially understood. Here, by means of thulium-yttrium/aluminum- garnet laser and event-related functional MRI, we tested whether variability in perception of identical stimuli relates to differences in prestimulus, baseline brain activity. Results indicate a positive relationship between conscious perception of low-intensity somatosensory stimuli and immediately preceding levels of baseline activity in medial thalamus and the lateral frontoparietal network, respectively, which are thought to relate to vigilance and "external monitoring." Conversely, there was a negative correlation between subsequent reporting of conscious perception and baseline activity in a set of regions encompassing posterior cingulate/ precuneus and temporoparietal cortices, possibly relating to introspection and self-oriented processes. At nociceptive levels of stimulation, pain-intensity ratings positively correlated with baseline fluctuations in anterior cingulate cortex in an area known to be involved in the affective dimension of pain. These results suggest that baseline brain-activity fluctuations may profoundly modify our conscious perception of the external world.