Heinen Klaartje, Feredoes Eva, Ruff Christian C, Driver Jon
Institute of Cognitive Neuroscience, University College London, London WC1N 3AR, UK; Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3BG, UK.
Institute of Cognitive Neuroscience, University College London, London WC1N 3AR, UK; Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3BG, UK.
Neuropsychologia. 2017 May;99:81-91. doi: 10.1016/j.neuropsychologia.2017.02.024. Epub 2017 Feb 28.
It is well established that the frontal eye-fields (FEF) in the dorsal attention network (DAN) guide top-down selective attention. In addition, converging evidence implies a causal role for the FEF in attention shifting, which is also known to recruit the ventral attention network (VAN) and fronto-striatal regions. To investigate the causal influence of the FEF as (part of) a central hub between these networks, we applied thetaburst transcranial magnetic stimulation (TBS) off-line, combined with functional magnetic resonance (fMRI) during a cued visuo-spatial attention shifting paradigm. We found that TBS over the right FEF impaired performance on a visual discrimination task in both hemifields following attention shifts, while only left hemifield performance was affected when participants were cued to maintain the focus of attention. These effects recovered ca. 20min post stimulation. Furthermore, particularly following attention shifts, TBS suppressed the neural signal in bilateral FEF, right inferior and superior parietal lobule (IPL/SPL) and bilateral supramarginal gyri (SMG). Immediately post stimulation, functional connectivity was impaired between right FEF and right SMG as well as right putamen. Importantly, the extent of decreased connectivity between right FEF and right SMG correlated with behavioural impairment following attention shifts. The main finding of this study demonstrates that influences from right FEF on SMG in the ventral attention network causally underly attention shifts, presumably by enabling disengagement from the current focus of attention.
众所周知，背侧注意网络（DAN）中的额叶眼区（FEF）引导自上而下的选择性注意。此外，越来越多的证据表明FEF在注意力转移中起因果作用，而注意力转移也会激活腹侧注意网络（VAN）和额纹状体区域。为了研究FEF作为这些网络之间（部分）中枢枢纽的因果影响，我们在一个线索化视觉空间注意力转移范式中，离线应用theta爆发式经颅磁刺激（TBS），并结合功能磁共振成像（fMRI）。我们发现，对右侧FEF进行TBS会损害注意力转移后两个半视野的视觉辨别任务表现，而当参与者被提示保持注意力集中时，只有左半视野的表现会受到影响。这些影响在刺激后约20分钟恢复。此外，特别是在注意力转移后，TBS抑制了双侧FEF、右侧顶叶上下小叶（IPL/SPL）和双侧缘上回（SMG）的神经信号。刺激后立即发现，右侧FEF与右侧SMG以及右侧壳核之间的功能连接受损。重要的是，右侧FEF与右侧SMG之间连接性降低的程度与注意力转移后的行为损伤相关。这项研究的主要发现表明，右侧FEF对腹侧注意网络中SMG的影响因果性地支撑了注意力转移，大概是通过使脱离当前注意力焦点来实现的。
