A Gradient of Sharpening Effects by Perceptual Prior across the Human Cortical Hierarchy
A Gradient of Sharpening Effects by Perceptual Prior across the Human Cortical Hierarchy
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DOI：
10.1523/jneurosci.2023-20.2020
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发表时间：
2021-01-06
影响因子：
5.3
通讯作者：
He, Biyu J.
中科院分区：
文献类型：
--
作者：
Gonzalez-Garcia, Carlos;He, Biyu J.
先验知识深刻地影响着知觉加工。以前的研究表明，在感觉区域预测的刺激信息一直受到抑制，但先前的知识如何调节大脑皮层更高层的加工仍然知之甚少。此外，导致抑制预测感觉信息的机制仍不清楚，到目前为止，研究揭示了一种混合的结果模式，支持“锐化”或“抑制”模型。在这里，我们在人类(男女)中使用7T功能磁共振成像，观察到从快速、一次性知觉学习中获得的先验知识增强了整个腹侧视觉流的神经表征，产生了抑制的感觉反应。相比之下，额顶和默认模式网络在内容特定的神经表征方面表现出类似的锐化，但分别在活动量不变和增强的背景下：我们将这种模式称为“选择性增强”。综上所述，这些结果揭示了一种迄今为止未知的宏观梯度，即先验知识对大脑皮层神经表示的锐化效应。
Prior knowledge profoundly influences perceptual processing. Previous studies have revealed consistent suppression of predicted stimulus information in sensory areas, but how prior knowledge modulates processing higher up in the cortical hierarchy remains poorly understood. In addition, the mechanism leading to suppression of predicted sensory information remains unclear, and studies thus far have revealed a mixed pattern of results in support of either the "sharpening" or "dampening" model. Here, using 7T fMRI in humans (both sexes), we observed that prior knowledge acquired from fast, one-shot perceptual learning sharpens neural representation throughout the ventral visual stream, generating suppressed sensory responses. In contrast, the frontoparietal and default mode networks exhibit similar sharpening of content-specific neural representation, but in the context of unchanged and enhanced activity magnitudes, respectively: a pattern we refer to as "selective enhancement." Together, these results reveal a heretofore unknown macroscopic gradient of prior knowledge's sharpening effect on neural representations across the cortical hierarchy.