Talcott Travis N, Kiat John E, Luck Steven J, Gaspelin Nicholas
Department of Psychology, Binghamton University, State University of New York, P.O. Box 6000, Binghamton, NY, 13902-6000, USA.
Center for Mind and Brain, University of California, Davis, CA, USA.
Atten Percept Psychophys. 2025 Jan;87(1):172-190. doi: 10.3758/s13414-023-02775-5. Epub 2023 Aug 23.
For decades, researchers have assumed that shifts of covert attention mandatorily occur prior to eye movements to improve perceptual processing of objects before they are fixated. However, recent research suggests that the N2pc component-a neural measure of covert attentional allocation-does not always precede eye movements. The current study investigated whether the N2pc component mandatorily precedes eye movements and assessed its role in the accuracy of gaze control. In three experiments, participants searched for a letter of a specific color (e.g., red) and directed gaze to it as a response. Electroencephalograms and eye movements were coregistered to determine whether neural markers of covert attention preceded the initial shift of gaze. The results showed that the presaccadic N2pc only occurred under limited conditions: when there were many potential target locations and distractors. Crucially, there was no evidence that the presence or magnitude of the presaccadic N2pc was associated with improved eye movement accuracy in any of the experiments. Interestingly, ERP decoding analyses were able to classify the target location well before the eyes started to move, which likely reflects a presaccadic cognitive process that is distinct from the attentional process measured by the N2pc. Ultimately, we conclude that the covert attentional mechanism indexed by the N2pc is not necessary for precise gaze control.
几十年来，研究人员一直认为，隐蔽性注意力转移必然发生在眼动之前，以便在物体被注视之前改善其感知加工。然而，最近的研究表明，N2pc成分（一种隐蔽性注意力分配的神经测量指标）并不总是先于眼动出现。本研究调查了N2pc成分是否必然先于眼动，并评估了其在注视控制准确性中的作用。在三个实验中，参与者寻找特定颜色（如红色）的字母，并将目光指向该字母作为反应。同时记录脑电图和眼动，以确定隐蔽性注意力的神经标记是否先于最初的目光转移。结果表明，眼跳前的N2pc仅在有限的条件下出现：即存在许多潜在目标位置和干扰物时。至关重要的是，在任何实验中，都没有证据表明眼跳前N2pc的出现或幅度与眼动准确性的提高有关。有趣的是，ERP解码分析能够在眼睛开始移动之前很好地对目标位置进行分类，这可能反映了一种眼跳前的认知过程，它与由N2pc测量的注意力过程不同。最终，我们得出结论，由N2pc索引的隐蔽性注意力机制对于精确的注视控制并非必要。
