Neural temporal dynamics of facilitation and suppression in top-down guided feature-based attention

该项目旨在研究基于特征的注意（FBA）中促进和抑制的基本神经动力学。 注意领域的一个中心问题是，视觉加工是否是一种严格有限的资源，必须通过选择性注意来选择性地、节俭地分配。如果是这样的话，对一个刺激的注意力增强必然会导致对无人注意的干扰刺激的抑制。然而，在我们以前的研究中，我们调查了FBA中注意力转移的时间动态，我们不断发现一个双相过程，快速促进待关注的特征（颜色），然后抑制待忽略的特征（颜色），时间延迟约为120-140 ms。我们将提出一个新的统一的框架，时间神经元动力学的注意转移，整合的基本神经原则的神经增益，竞争和抑制的FBA。虽然我们多次重复了这一双相过程，但一些评论者在各自的出版过程中提出了一些关键问题，这些问题需要实验注意以排除其他解释。这些问题围绕着频率标记刺激的使用，主要是限制集中分析稳态视觉诱发电位（SSVEP）。在建议的项目中，我们打算运行3项研究，将我们的研究扩展到采用探针设计的行为数据，并同时分析由包括任务和探针刺激的事件引起的ERP。我们相信，这样一个多模态的方法将显着加强我们的建议，一个替代框架的分配注意力转移的注意力资源的FBA。在进一步的探索性研究中，我们打算测试的时间进程和时间点的抑制时，选择是由自上而下的选择驱动或由硬连线中心环绕抑制驱动。进一步的探索性研究旨在测试我们的想法，即早期增益调制和随后的竞争性相互作用并不是相互独立的，而是初始放大增益需要在触发抑制之前达到临界水平。如果抑制起作用，我们想测试促进和抑制是否会导致竞争性相互作用中的互惠关系。我们相信，这些发现将丰富现有的注意力模型，因此，也应该是最感兴趣的计算模型和放大和抑制的方式在各自的算法中实现。

The proposed project sets out to investigate basic neural dynamics of facilitation and suppression in feature-based attention (FBA). A central question in the field of attention is whether visual processing is a strictly limited resource, which must be selectively and frugally allocated by selective attention. If this were the case, attentional enhancement of one stimulus should invariably lead to suppression of unattended distracter stimuli. However, in our previous studies in which we investigated the temporal dynamics of attentional shifts in FBA, we constantly found a biphasic process, with fast facilitation of the to-be-attended feature (color) followed by suppression of the to-be-ignored feature (color) with a time delay in the range of about 120-140 ms. Here, we will propose a new unified framework of temporal neuronal dynamics of attentional shifting that integrates the basic neural principles of neural gain, competition and suppression in FBA. While we replicated that biphasic process several times, some reviewers were asking some critical questions during the respective publication process that need experimental attention to exclude alternative explanations. These questions revolved around the usage of frequency-tagged stimuli and mainly the restriction to focus the analysis to steady state visual evoked potentials (SSVEPs). In the suggested project, we intend to run 3 studies extending our research to behavioral data employing a probe design and concurrently analyze ERPs that are elicited by events that comprise the task and probe stimuli. We are convinced that such a multi-modal approach will significantly strengthen our suggestion for an alternative framework for the allocation of attentional resources of attentional shifts in FBA. In further explorative studies, we intend to test the time course and the time point of suppression when selection is driven by top-down selection or driven by hard-wired center surround suppression. A further explorative study intends to test our idea that early gain modulation and the subsequent competitive interactions are not independent of each other, but instead, that initial amplification gain needs to reach a critical level before it triggers suppression. If suppression comes into play, we want to test whether facilitation and suppression result in a reciprocal relationship in that competitive interaction. We are convinced that these findings would enrich existing models of attention, and thus, should also be of highest interest to computational models and the way amplification and suppression are implemented in the respective algorithms.