School of Psychology and Neuroscience, University of Glasgow, Glasgow, G12 8QQ, UK.
Experimental Psychology, Helmholtz Institute, Utrecht University, 3584 CS, Utrecht, The Netherlands.
Sci Rep. 2023 Apr 10;13(1):5830. doi: 10.1038/s41598-023-32980-z.
Every time we move our eyes, the retinal locations of objects change. To distinguish the changes caused by eye movements from actual external motion of the objects, the visual system is thought to anticipate the consequences of eye movements (saccades). Single neuron recordings have indeed demonstrated changes in receptive fields before saccade onset. Although some EEG studies with human participants have also demonstrated a pre-saccadic increased potential over the hemisphere that will process a stimulus after a saccade, results have been mixed. Here, we used magnetoencephalography to investigate the timing and lateralization of visually evoked planar gradients before saccade onset. We modelled the gradients from trials with both a saccade and a stimulus as the linear combination of the gradients from two conditions with either only a saccade or only a stimulus. We reasoned that any residual gradients in the condition with both a saccade and a stimulus must be uniquely linked to visually-evoked neural activity before a saccade. We observed a widespread increase in residual planar gradients. Interestingly, this increase was bilateral, showing activity both contralateral and ipsilateral to the stimulus, i.e. over the hemisphere that would process the stimulus after saccade offset. This pattern of results is consistent with predictive pre-saccadic changes involving both the current and the future receptive fields involved in processing an attended object, well before the start of the eye movement. The active, sensorimotor coupling of vision and the oculomotor system may underlie the seamless subjective experience of stable and continuous perception.
每次我们移动眼睛时，视网膜上物体的位置都会发生变化。为了将眼球运动引起的变化与物体的实际外部运动区分开来，人们认为视觉系统会预测眼球运动（扫视）的结果。单神经元记录确实表明，在扫视开始之前，感受野会发生变化。尽管一些涉及人类参与者的 EEG 研究也表明，在扫视后处理刺激的半球上，在扫视前会出现电位增加，但结果却不一致。在这里，我们使用脑磁图研究了扫视前视觉诱发的平面梯度的时间和侧化。我们将有扫视和刺激的试验中的梯度建模为仅扫视或仅刺激两种条件下梯度的线性组合。我们推断，在有扫视和刺激的条件下的任何剩余梯度都必须与扫视前的视觉诱发神经活动有独特的联系。我们观察到广泛的剩余平面梯度增加。有趣的是，这种增加是双侧的，在刺激的对侧和同侧都显示出活动，即在扫视结束后处理刺激的半球上。这种结果模式与涉及当前和未来感受野的预测性扫视前变化一致，这些变化在眼球运动开始之前很早就发生了。视觉和眼动系统的主动、感觉运动耦合可能是稳定和连续感知的无缝主观体验的基础。
