Abstract Perceptual filling-in (PFI) occurs when a physically present visual target disappears from conscious perception, with its location filled-in by the surrounding visual background. These perceptual changes are complete, near instantaneous, and can occur for multiple separate locations simultaneously. Here, we show that contrasting neural activity during the presence or absence of multi-target PFI can complement other findings from multistable phenomena to reveal the neural correlates of consciousness (NCC). We presented four peripheral targets over a background dynamically updating at 20 Hz. While participants reported on target disappearances/reappearances via button press/release, we tracked neural activity entrained by the background during PFI using steady-state visually evoked potentials (SSVEPs) recorded in the electroencephalogram. We found background SSVEPs closely correlated with subjective report, and increased with an increasing amount of PFI. Unexpectedly, we found that as the number of filled-in targets increased, the duration of target disappearances also increased, suggesting that facilitatory interactions exist between targets in separate visual quadrants. We also found distinct spatiotemporal correlates for the background SSVEP harmonics. Prior to genuine PFI, the response at the second harmonic (40 Hz) increased before the first (20 Hz), which we tentatively link to an attentional effect, while no such difference between harmonics was observed for physically removed stimuli. These results demonstrate that PFI can be used to study multi-object perceptual suppression when frequency-tagging the background of a visual display, and because there are distinct neural correlates for endogenously and exogenously induced changes in consciousness, that it is ideally suited to study the NCC.

中文翻译：

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多响应频率标签范式可测量知觉填充过程中意识的分级变化

摘要感知填充（PFI）发生在物理存在的视觉目标从意识感知中消失时，其位置被周围的视觉背景所填充。这些感知变化是完整的，几乎是瞬时的，并且可以同时在多个单独的位置发生。在这里，我们表明存在或不存在多目标PFI期间神经活动的对比可以补充多稳态现象的其他发现，从而揭示意识的神经相关性（NCC）。我们以20 Hz动态更新的背景介绍了四个外围目标。当参与者通过按动按钮/释放按钮报告目标消失/重新出现时，我们使用脑电图中记录的稳态视觉诱发电位（SSVEP）跟踪了PFI期间背景所夹带的神经活动。我们发现背景SSVEP与主观报告密切相关，并且随着PFI量的增加而增加。出乎意料的是，我们发现随着填充目标数量的增加，目标消失的持续时间也增加，这表明目标之间在单独的视觉象限中存在促进性相互作用。我们还发现背景SSVEP谐波具有明显的时空相关性。在真正的PFI之前，第二谐波（40 Hz）的响应在第一谐波（20 Hz）之前增加，我们将其暂时联系到注意力效应，而对于物理去除的刺激，谐波之间没有观察到这种差异。这些结果表明，当对视觉显示器的背景进行频率标记时，PFI可用于研究多对象感知抑制，