Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1A, 04103 Leipzig, Germany.
Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1A, 04103 Leipzig, Germany; Experimental Psychology and Methods, Faculty of Life Sciences, University of Leipzig, 04109 Leipzig, Germany.
Neuroimage. 2021 Jan 1;224:117384. doi: 10.1016/j.neuroimage.2020.117384. Epub 2020 Sep 17.
Theories of human consciousness substantially vary in the proposed spatial extent of brain activity associated with conscious perception as well as in the assumed functional alterations within the involved brain regions. Here, we investigate which local and global changes in brain activity accompany conscious somatosensory perception following electrical finger nerve stimulation, and whether there are whole-brain functional network alterations by means of graph metrics. Thirty-eight healthy participants performed a somatosensory detection task and reported their decision confidence during fMRI. For conscious tactile perception in contrast to undetected near-threshold trials (misses), we observed increased BOLD activity in the precuneus, the intraparietal sulcus, the insula, the nucleus accumbens, the inferior frontal gyrus and the contralateral secondary somatosensory cortex. For misses compared to correct rejections, bilateral secondary somatosensory cortices, supplementary motor cortex and insula showed greater activations. The analysis of whole-brain functional network topology for hits, misses and correct rejections, did not result in any significant differences in modularity, participation, clustering or path length, which was supported by Bayes factor statistics. In conclusion, for conscious somatosensory perception, our results are consistent with an involvement of (probably) domain-general brain areas (precuneus, insula, inferior frontal gyrus) in addition to somatosensory regions; our data do not support the notion of specific changes in graph metrics associated with conscious experience. For the employed somatosensory submodality of fine electrical current stimulation, this speaks for a global broadcasting of sensory content across the brain without substantial reconfiguration of the whole-brain functional network resulting in an integrative conscious experience.
人类意识理论在与有意识感知相关的大脑活动的提出空间范围以及所涉及的大脑区域的假定功能改变方面有很大的不同。在这里,我们研究了在电手指神经刺激后伴随有意识的体感感知的大脑活动的局部和全局变化,以及是否通过图度量存在全脑功能网络改变。三十八名健康参与者在 fMRI 期间执行体感检测任务并报告他们的决策信心。与未检测到的阈下试验(漏报)相比,我们观察到在楔前叶、顶内沟、岛叶、伏隔核、额下回和对侧次级体感皮层中 BOLD 活动增加。与正确拒绝相比,漏报在双侧次级体感皮层、补充运动皮层和岛叶显示出更大的激活。对命中、漏报和正确拒绝的全脑功能网络拓扑的分析没有导致模块性、参与度、聚类或路径长度的任何显著差异,贝叶斯因子统计支持这一结果。总之,对于有意识的体感感知,我们的结果与(可能)域一般的大脑区域(楔前叶、岛叶、额下回)的参与一致,除了体感区域之外;我们的数据不支持与意识体验相关的图度量的特定变化的概念。对于所采用的精细电流刺激体感亚模式,这表明在大脑中没有实质性的全脑功能网络重新配置的情况下,将感官内容全局广播,从而产生整体的意识体验。