Département Traitement de l'Information et Systèmes, Office National d'Études et de Recherches Aérospatiales, Salon-de-Provence 13661, France
Institut de Neurosciences de la Timone (Unité Mixte de Recherche 7289), Centre National de la Recherche Scientifique, Aix-Marseille Université, Marseille 13005, France.
J Neurosci. 2023 Mar 15;43(11):1933-1939. doi: 10.1523/JNEUROSCI.0563-22.2022. Epub 2023 Feb 9.
We are constantly sampling our environment by moving our eyes, but our subjective experience of the world is stable and constant. Stimulus displacement during or shortly after a saccade often goes unnoticed, a phenomenon called the saccadic suppression of displacement. Although we fail to notice such displacements, our oculomotor system computes the prediction errors and adequately adjusts the gaze and future saccadic execution, a phenomenon known as saccadic adaptation. In the present study, we aimed to find a brain signature of the trans-saccadic prediction error that informs the motor system but not explicit perception. We asked participants (either sex) to report whether a visual target was displaced during a saccade while recording electroencephalography (EEG). Using multivariate pattern analysis, we were able to differentiate displacements from no displacements, even when participants failed to report the displacement. In other words, we found that trans-saccadic prediction error is represented in the EEG signal 100 ms after the displacement presentation, mainly in occipital and parieto-occipital channels, even in the absence of explicit perception of the displacement. Stability in vision occurs even while performing saccades. One suggested mechanism for this counterintuitive visual phenomenon is that external displacement is suppressed during the retinal remapping caused by a saccade. Here, we shed light on the mechanisms of trans-saccadic stability by showing that displacement information is not entirely suppressed and specifically present in the early stages of visual processing. Such a signal is relevant and computed for oculomotor adjustment despite being neglected for perception.
我们通过移动眼睛不断地对周围环境进行采样，但我们对世界的主观体验是稳定且一致的。在眼跳期间或之后不久，刺激的位移通常会被忽略，这种现象被称为眼跳抑制。尽管我们没有注意到这些位移，但我们的眼球运动系统会计算预测误差，并适当地调整注视和未来的眼跳执行，这种现象被称为眼跳适应。在本研究中，我们旨在寻找一个跨眼跳预测误差的大脑特征，该特征可以向运动系统提供信息，但不会提供明显的感知。我们要求参与者（无论性别）在进行眼跳时报告视觉目标是否在眼跳过程中发生了位移，同时记录脑电图（EEG）。使用多元模式分析，我们能够区分位移和无位移，即使参与者未能报告位移。换句话说，我们发现跨眼跳预测误差在位移呈现后 100 毫秒即在脑电图信号中得到表示，主要在枕叶和顶枕叶通道中，即使没有明显感知到位移。在执行眼跳时，视觉稳定性仍然存在。一种解释这种反直觉视觉现象的机制是，外部位移在眼跳引起的视网膜重映射过程中被抑制。在这里，我们通过表明位移信息并未完全被抑制，并且特别存在于视觉处理的早期阶段，从而揭示了跨眼跳稳定性的机制。尽管这种信号被忽视了，但它与感知无关，而是与眼球运动调整相关。
