Low-Level Visual Information Is Maintained across Saccades, Allowing for a Postsaccadic Handoff between Visual Areas.
Low-Level Visual Information Is Maintained across Saccades, Allowing for a Postsaccadic Handoff between Visual Areas.
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DOI：
10.1523/jneurosci.1169-20.2020
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发表时间：
2020-12-02
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影响因子：
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通讯作者：
Melcher D
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文献类型：
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作者：
Fabius JH;Fracasso A;Acunzo DJ;Van der Stigchel S;Melcher D
尽管扫视眼球运动每秒改变视网膜输入几次，但体验似乎是连续和详细的。有争议的神经信号更新跨越眼跳是否包含刺激功能的信息，或只有位置指针没有视觉细节。我们研究了低层次的视觉信息处理的时间过程中扫视通过解码的空间频率的固定刺激，改变从一个视觉半野到其他，因为一个水平扫视眼球运动。我们记录脑磁图，而人类受试者（男女）监测光栅刺激的方向，使空间频率任务无关。单独的试验中，受试者保持固定，被用来训练分类器，其性能，然后测试眼跳试验。解码性能表明，空间频率信息的前视刺激仍然存在的200毫秒后扫视，超越视网膜特异性。眼跳后信息在眼跳偏移后迅速增加。有一个重叠超过100毫秒，在此期间，解码是显着的，从两个presaccadic和postsaccadic处理区。这表明，跨越扫视的感知的明显丰富性可以通过在新注视的初始处理扫描期间具有信息的“软切换”的低级别信息的连续可用性来支持。显著性陈述扫视在视觉输入中产生频繁的不连续性，然而感知似乎是稳定和连续的。这种不连续的输入是如何处理的，从而导致视觉稳定性？以前的研究主要集中在preaccadic重新映射。在这里，我们研究了低层次的视觉信息（空间频率）的处理时间过程中的眼跳与脑磁图。结果表明，空间频率信息没有预测重新映射，但也没有被丢弃。相反，他们建议随着时间的推移在不同的视觉区域之间进行软切换，使这些信息在扫视过程中持续可用。关于扫视前刺激的信息仍然可用，而关于扫视后刺激的信息也变得可用。扫视前和扫视后信息的同时可用性可以使跨越扫视的丰富和连续的感知成为可能。
Experience seems continuous and detailed despite saccadic eye movements changing retinal input several times per second. There is debate whether neural signals related to updating across saccades contain information about stimulus features, or only location pointers without visual details. We investigated the time course of low-level visual information processing across saccades by decoding the spatial frequency of a stationary stimulus that changed from one visual hemifield to the other because of a horizontal saccadic eye movement. We recorded magnetoencephalography while human subjects (both sexes) monitored the orientation of a grating stimulus, making spatial frequency task irrelevant. Separate trials, in which subjects maintained fixation, were used to train a classifier, whose performance was then tested on saccade trials. Decoding performance showed that spatial frequency information of the presaccadic stimulus remained present for ∼200 ms after the saccade, transcending retinotopic specificity. Postsaccadic information ramped up rapidly after saccade offset. There was an overlap of over 100 ms during which decoding was significant from both presaccadic and postsaccadic processing areas. This suggests that the apparent richness of perception across saccades may be supported by the continuous availability of low-level information with a “soft handoff” of information during the initial processing sweep of the new fixation. SIGNIFICANCE STATEMENT Saccades create frequent discontinuities in visual input, yet perception appears stable and continuous. How is this discontinuous input processed resulting in visual stability? Previous studies have focused on presaccadic remapping. Here we examined the time course of processing of low-level visual information (spatial frequency) across saccades with magnetoencephalography. The results suggest that spatial frequency information is not predictively remapped but also is not discarded. Instead, they suggest a soft handoff over time between different visual areas, making this information continuously available across the saccade. Information about the presaccadic stimulus remains available, while the information about the postsaccadic stimulus has also become available. The simultaneous availability of both the presaccadic and postsaccadic information could enable rich and continuous perception across saccades.