Goltz Dominique, Pleger Burkhard, Thiel Sabrina D, Villringer Arno, Müller Matthias M
Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany ; Institute of Psychology, University of Leipzig, Leipzig, Germany.
Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany ; Clinic for Cognitive Neurology, University Hospital Leipzig, Leipzig, Germany.
PLoS One. 2013 Dec 19;8(12):e84196. doi: 10.1371/journal.pone.0084196. eCollection 2013.
The present functional magnetic resonance imaging (fMRI) study was designed to get a better understanding of the brain regions involved in sustained spatial attention to tactile events and to ascertain to what extent their activation was correlated. We presented continuous 20 Hz vibrotactile stimuli (range of flutter) concurrently to the left and right index fingers of healthy human volunteers. An arrow cue instructed subjects in a trial-by-trial fashion to attend to the left or right index finger and to detect rare target events that were embedded in the vibrotactile stimulation streams. We found blood oxygen level-dependent (BOLD) attentional modulation in primary somatosensory cortex (SI), mainly covering Brodmann area 1, 2, and 3b, as well as in secondary somatosensory cortex (SII), contralateral to the to-be-attended hand. Furthermore, attention to the right (dominant) hand resulted in additional BOLD modulation in left posterior insula. All of the effects were caused by an increased activation when attention was paid to the contralateral hand, except for the effects in left SI and insula. In left SI, the effect was related to a mixture of both a slight increase in activation when attention was paid to the contralateral hand as well as a slight decrease in activation when attention was paid to the ipsilateral hand (i.e., the tactile distraction condition). In contrast, the effect in left posterior insula was exclusively driven by a relative decrease in activation in the tactile distraction condition, which points to an active inhibition when tactile information is irrelevant. Finally, correlation analyses indicate a linear relationship between attention effects in intrahemispheric somatosensory cortices, since attentional modulation in SI and SII were interrelated within one hemisphere but not across hemispheres. All in all, our results provide a basis for future research on sustained attention to continuous vibrotactile stimulation in the range of flutter.
本功能磁共振成像（fMRI）研究旨在更好地了解参与对触觉事件持续空间注意的脑区，并确定其激活程度的相关性。我们同时向健康人类志愿者的左手和右手食指施加连续的20 Hz振动触觉刺激（颤动范围）。一个箭头提示以逐次试验的方式指示受试者关注左手或右手食指，并检测嵌入在振动触觉刺激流中的罕见目标事件。我们发现，在主要覆盖布罗德曼区1、2和3b的初级体感皮层（SI）以及与待关注手对侧的次级体感皮层（SII）中存在血氧水平依赖（BOLD）注意调制。此外，对右手（优势手）的注意导致左后岛叶出现额外的BOLD调制。所有这些效应都是由于对侧手被关注时激活增加所致，但左SI和岛叶的效应除外。在左SI中，该效应与对侧手被关注时激活略有增加以及同侧手被关注时激活略有减少（即触觉分心条件）的混合情况有关。相比之下，左后岛叶的效应完全由触觉分心条件下激活的相对减少驱动，这表明当触觉信息不相关时存在主动抑制。最后，相关性分析表明半球内体感皮层的注意效应之间存在线性关系，因为SI和SII中的注意调制在一个半球内相互关联，但跨半球则不然。总之，我们的结果为未来关于对颤动范围内连续振动触觉刺激持续注意的研究提供了基础。
