Martín-Signes Mar, Cano-Melle Cristina, Chica Ana B
Department of Experimental Psychology, and Mind, Brain, and Behavior Research Center (CIMCYC), University of Granada, Granada, Spain.
Department of Experimental Psychology, and Mind, Brain, and Behavior Research Center (CIMCYC), University of Granada, Granada, Spain.
Cortex. 2021 Jan;134:1-15. doi: 10.1016/j.cortex.2020.09.027. Epub 2020 Oct 17.
The executive control network is involved in novel situations or those in which prepotent responses need to be overridden. Previous studies have demonstrated that when control is exerted, conscious perception is impaired, and this effect is related to the functional connectivity of fronto-parietal regions. In the present study, we explored the causal involvement of one of the nodes of this fronto-parietal network (the right Supplementary Motor Area, SMA) in the interaction between executive control and conscious perception. Participants performed a dual task in which they responded to a Stroop task while detecting the presence/absence of a near-threshold Gabor stimulus. Concurrently, transcranial magnetic stimulation (TMS) was applied over the right SMA or a control site (vertex; Experiment 1). As a further control, the right Frontal Eye Field (FEF) was stimulated in Experiment 2. Diffusion-weighted imaging (DWI) tractography was used to isolate the three branches of the superior longitudinal fasciculus (SLF I, II and III), and the frontal aslant tract (FAT), and to explore if TMS effects were related to their micro- and macrostructural characteristics. Results demonstrated reduced perceptual sensitivity on incongruent as compared to congruent Stroop trials. A causal role of the right SMA on the modulation of perceptual sensitivity by executive control was only demonstrated when the microstructure of the right SLF III or the left FAT were taken into account. The volume of the right SLF III was also related to the modulation of response criterion by executive control when the right FEF was stimulated. These results add evidence in favor of shared neural correlates for attention and conscious perception in fronto-parietal regions and highlight the role of white matter in TMS effects.
执行控制网络参与处理新情况或需要抑制优势反应的情况。先前的研究表明，当执行控制时，意识感知会受损，并且这种效应与额顶叶区域的功能连接有关。在本研究中，我们探讨了这个额顶叶网络的一个节点（右侧辅助运动区，SMA）在执行控制与意识感知之间的相互作用中的因果关系。参与者执行了一项双重任务，即他们在检测近阈值Gabor刺激的有无时对Stroop任务做出反应。同时，经颅磁刺激（TMS）施加于右侧SMA或一个对照部位（头顶；实验1）。作为进一步的对照，在实验2中刺激了右侧额眼区（FEF）。使用扩散加权成像（DWI）纤维束成像来分离上纵束的三个分支（SLF I、II和III）以及额斜束（FAT），并探讨TMS效应是否与其微观和宏观结构特征有关。结果表明，与一致的Stroop试验相比，不一致试验中的感知敏感性降低。只有在考虑右侧SLF III或左侧FAT的微观结构时，才证明右侧SMA在执行控制对感知敏感性的调节中具有因果作用。当刺激右侧FEF时，右侧SLF III的体积也与执行控制对反应标准的调节有关。这些结果为额顶叶区域注意力和意识感知的共享神经关联提供了更多证据，并突出了白质在TMS效应中的作用。
