Neural correlates of visual ambiguity and meta-perceptual confidence rating

我们感官获得的信息是不完整和模糊的。我们的感知系统通常将这种自下而上的感觉信息与自上而下的感知记忆相结合，以解决这种模糊性，并构建稳定可靠的感知。在观察一个模糊的图形时，我们的感知变得不稳定，并在两种同样可能但相互排斥的解释之间交替。我们最近发现两个ERP成分（P200和P400）在歧义图形和消歧义图形变体（ERP歧义效应）的诱发下具有小振幅和大振幅。这些异常强烈的效果可以在不同的视觉类别和复杂程度（动作、语义、面部表情和字母/数字）中得到推广。最近的一项关于内克尔立方体刺激的研究完美地证实了一种关于知觉加工的预测编码模型。该模型表明P200与自上而下对知觉过程的贡献有关。P400似乎反映了自下而上和自上而下因素的整合，从而反映了感知结果的可靠性。这些发现和引入的模型是这个由三个项目组成的资助提案的起点：项目A：跨视觉类别和复杂性水平的泛化性测试。到目前为止，ERP模糊效应和预测编码模型之间的关系仅在Necker立方体刺激中得到证实。我们计划测试这些符合模型的发现是否适用于上述其他刺激类别和复杂性水平。项目B: SSD患者ERP模糊效应的测试精神分裂症谱系障碍（SSD）患者在自下而上的感觉与自上而下的信息整合方面存在缺陷。我们计划测试这种整合缺陷是否反映在ERP模糊效应的偏离模式中。项目C：关于神经源的ERP模糊效应的泛化性测试迄今为止，ERP模糊效应的空间位置是基于脑电图电压图的。本子项目的目的是，使用并发EEG/fMRI记录：(1)确定不同刺激类别和复杂程度的相似ERP头皮分布是否如模型预测的那样基于相同的底层神经源。(2)识别SSD患者与对照组感知消歧过程的脑区及其差异。本项目在神经生物学、知觉心理学和精神病学的交叉领域的研究结果可能会促进对ERP模糊效应的神经和功能特征的理解，以及对知觉的预测编码方法。鉴于ERP模糊效应的规模较大，本项目的结果可能具有良好的临床应用前景。

The information available to our senses is incomplete and ambiguous. Our perceptual system normally integrates this the bottom-up sensory information with top-down perceptual memories in order to resolve this ambiguity and to construct stable and reliable percepts. During observation of an ambiguous figure our perception becomes unstable and alternates between two equally probable but mutual exclusive interpretations. We recently found two ERP components (P200 and P400) with small vs. large amplitudes evoked by ambiguous figures vs. disambiguated figure variants (ERP Ambiguity Effects). These unusually strong effects generalize across very different visual categories and complexity levels (motion, semantics, emotional face expressions and letters/numbers). A recent study with Necker cube stimuli revealed perfect confirmation of a predictive coding model about perceptual processing. The model indicates that the P200 correlates with top-down contributions to the perceptual process. The P400 seems to reflect the integration of bottom-up and top-down elements and thus the reliability of the perceptual outcome. These findings and the introduced model are the starting point of this grant proposal consisting of three projects:Project A: Testing for generalizability across visual categories and complexity levelsSo far, the relation between the ERP Ambiguity Effects and the predictive coding model has only been shown for Necker cube stimuli. We plan to test whether these model-conform findings generalize across other stimulus categories and complexity levels mentioned above.Project B: Test for ERP Ambiguity Effects alterations in SSD PatientsPatients with schizophrenia spectrum disorder (SSD) show deficits in integrating bottom-up sensory with top-down information. We plan to test whether this integration deficit is reflected in a deviated pattern of ERP Ambiguity Effects. Project C: Testing for generalizability of the ERP Ambiguity Effects concerning neural sourcesThe spatial locations of the ERP Ambiguity Effects are so far based on EEG voltage maps. The aims of this subproject are, using concurrent EEG/fMRI recordings: (1) To specify whether similar ERP scalp distributions across different stimulus categories and complexity levels are based on the same underlying neural sources, as predicted by the model. (2) To identify brain areas underlying perceptual disambiguation processes and respective differences between SSD patients and controls. The results of this project at the interface between neurobiology, psychology of perception and psychiatry may advance the understanding of the neural and functional features of the ERP Ambiguity Effects and predictive coding approaches to perception. Given the large sizes of the ERP Ambiguity Effects, the results from the current project may have a good prospect for future clinical applications.