Neuronal interaction between spatial- and feature-based attention in visual object processing

注意是从大量可能的信息中选择行为相关刺激的关键机制。三种基本的选择原则，即基于空间、基于对象和基于特征的选择，在过去得到了深入的研究。然而，仔细看一下文献就会发现，这些机制大多是孤立地探索的，只有少数人试图发现三者之间的异同或相互作用。日常经验告诉我们，在这些选择原则之间需要不断地转换，以提取我们环境的连贯图像。因此，令人惊讶的是，我们对这方面的神经动力学、协调和相互作用知之甚少。在基于对象的注意力的基础上，该项目将研究当应用基于空间或特征的选择标准时的神经（时间）动态。我的研究表明，关注一个物体的一个与任务相关的特征并不会自动促进神经处理构成该物体的与任务无关的特征。此外，在另一个实验中，我们已经证明基于特征的注意力是强制性的，甚至覆盖了任务需求。这些和其他实验结果为进一步阐明基于对象、空间和特征的选择之间的神经相互作用和基本原理奠定了基础。通过我们创新的刺激技术，即呈现频率标记刺激，在人类脑电图中唤起稳态诱发电位（SSVEPs），我们将能够揭示早期视觉皮层中竞争处理的基本神经动力学，包括其时间动力学。所有实验的理论框架都是基于“有偏竞争模型”来解释竞争相互作用。

Attention is the key mechanism to select behaviorally relevant stimuli out of the flood of possible information. Three basic selection principles, i.e. spatial-, object- and feature-based selection, were intensively investigated in the past. However, a closer look to the literature shows that these mechanisms were mostly explored in isolation with only a few attempts to discover similarities/dissimilarities or interactions between the three. Everyday experience teaches us that a constant shift between these selection principles is required to extract a coherent image of our environment. Therefore, it is surprising how little is known about the neural dynamics, coordination and interactions in this regard. On the basis of object-based attention, the proposed project will investigate the neural (temporal) dynamics when spatial- or feature-based selection criteria are applied. Own work has shown that attending to one task-relevant feature of an object does not automatically facilitate neural processing of the task-irrelevant feature that constitutes the object. Furthermore, in a different experiment we have shown that feature-based attention is obligatory and overwrites even task-demands. These and other experimental results lay ground of the proposed experiments to shed further light on the neural interactions and basic principles between object-, spatial- and feature-based selection. By means of our innovative stimulation technique, i.e. to present frequency-tagged stimuli that evoke steady state evoked potentials (SSVEPs) in the human EEG, we will be able to uncover basic neural dynamics in early visual cortex in competition for processing, including temporal dynamics thereof. The theoretical framework of all experiments is based on the "biased competition model" to explain competitive interactions.