Department of Neuroscience, Imaging and Clinical Sciences, Institute for Advanced Biomedical Technologies (ITAB), G.D'Annunzio University, Chieti, Italy.
Institute of Psychology, Jagiellonian University, Krakow, Poland.
Brain Connect. 2021 Nov;11(9):717-724. doi: 10.1089/brain.2020.0885. Epub 2021 Jun 1.
The endogenous allocation of spatial attention to selected environmental stimuli is controlled by prefrontal (frontal eye fields [FEFs]) and parietal (superior parietal lobe [SPL] and intraparietal sulcus [IPS]) regions belonging to the dorsal attention network (DAN) with a subdivision in subsystems devoted to reorienting (or shifting) of attention between locations (SPL) or maintaining attention at contralateral versus ipsilateral locations (ventral IPS [vIPS]). Although previous studies suggested a leading role of prefrontal regions over parietal sites in orienting attention, the spectral signature of communication flow within the DAN for different attention processes is still debated. We used the directed transfer function (DTF) on magnetoencephalography (MEG) data to examine the causal interaction between prefrontal and parietal regions of the DAN when subjects shifted versus maintained attention to a stream of cued visual stimuli. In the beta band, we found that shift versus stay cues induced stronger connectivity (DTF values) from right FEF to right SPL, in the early phase of reorienting. Conversely, when considering stay versus shift cues, an increase of DTF values and stronger directionality was observed between bilateral vIPS and from right vIPS to FEF. Similar analyses carried out in theta, alpha, and gamma showed no significant frontoparietal increases of DTF for shift versus stay cues, whereas the stay-related increase of DTF observed in beta between ventral parietal areas was preserved in the alpha band. These findings suggest that control processes in DAN regions (in particular between FEF and SPL) can be associated to a beta frequency channel during shift of attention. Impact statement In the present study, we compared the reorienting response to novel stimuli with respect to maintaining response. Results provided new insights into understanding the neural mechanisms of control attention processes by identifying the frequency-specific causal interactions between frontal and parietal regions belonging to the dorsal attention network supporting spatial reorienting response.
内源性分配空间注意到选定的环境刺激是由前额叶（额叶眼场[FEF]）和顶叶（上顶叶[SPL]和顶内沟[IPS]）区域控制的，这些区域属于背侧注意网络（DAN），其中有一个子系统专门用于在位置之间重新定向（或转移）注意力（SPL）或在对侧和同侧位置保持注意力（腹侧 IPS[vIPS]）。尽管先前的研究表明，前额叶区域在定向注意力方面优于顶叶区域，但不同注意力过程中 DAN 内的信息流的频谱特征仍存在争议。我们使用磁源成像（MEG）数据上的有向传递函数（DTF）来检查当被试将注意力转移到提示视觉刺激流时，前额叶和 DAN 顶叶区域之间的因果相互作用。在β频带中，我们发现与保持注意相比，在重新定向的早期阶段，从右 FEF 到右 SPL 的转移与保持提示会引起更强的连通性（DTF 值）。相反，当考虑保持与转移提示时，在双侧 vIPS 之间以及从右 vIPS 到 FEF 之间观察到 DTF 值增加和更强的方向性。在θ、α和γ频段中进行的类似分析显示，与保持注意相比，转移提示不会导致 DTF 值在额顶叶区域增加，而在β频段中在腹侧顶叶区域之间观察到的保持相关的 DTF 值在α频段中保持不变。这些发现表明，DAN 区域（特别是 FEF 和 SPL 之间）的控制过程可以与注意力转移时的β频带通道相关联。
