Reconstructing Perceived and Retrieved Faces from Activity Patterns in Lateral Parietal Cortex
Reconstructing Perceived and Retrieved Faces from Activity Patterns in Lateral Parietal Cortex
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DOI：
10.1523/jneurosci.4286-15.2016
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发表时间：
2016-06-01
影响因子：
5.3
通讯作者：
Kuhl, Brice A.
中科院分区：
文献类型：
--
作者：
Lee, Hongmi;Kuhl, Brice A.
最近的研究结果表明，记忆编码和检索的内容可以从角回（ANG）（后外侧顶叶皮层的一个子区域）解码。然而，典型的解码方法几乎无法洞察 ANG 内容表示的本质。在这里，我们测试了是否可以通过从人类的 fMRI 活动模式预测潜在的面部成分来从 ANG 重建复杂的多维刺激（面部）。使用受计算机视觉方法启发的人脸识别方法，我们将主成分分析应用于大量人脸图像以生成特征脸。然后，我们对特征脸值和功能磁共振成像活动模式之间的关系进行了建模。然后，使用个体面部引起的活动模式来生成预测的特征面部值，该特征面部值可以转化为个体面部的重建。我们表明，视觉感知的面孔是根据枕颞皮层和几个侧顶叶亚区域（包括 ANG）的活动模式可靠地重建的。对重建面部的主观评估揭示了在 ANG 中成功重建的特定信息来源（例如，情感和肤色）。引人注目的是，我们还发现，在面部感知过程中针对 ANG 活动模式进行训练的模型能够成功重建内存中保存的一组独立的面部图像。总之，这些发现提供了令人信服的证据，表明 ANG 形成了复杂的、特定于刺激的表征，这些表征反映在感知和记忆过程中引发的活动模式中。
Recent findings suggest that the contents of memory encoding and retrieval can be decoded from the angular gyrus (ANG), a subregion of posterior lateral parietal cortex. However, typical decoding approaches provide little insight into the nature of ANG content representations. Here, we tested whether complex, multidimensional stimuli (faces) could be reconstructed from ANG by predicting underlying face components from fMRI activity patterns in humans. Using an approach inspired by computer vision methods for face recognition, we applied principal component analysis to a large set of face images to generate eigenfaces. We then modeled relationships between eigenface values and patterns of fMRI activity. Activity patterns evoked by individual faces were then used to generate predicted eigenface values, which could be transformed into reconstructions of individual faces. We show that visually perceived faces were reliably reconstructed from activity patterns in occipitotemporal cortex and several lateral parietal subregions, including ANG. Subjective assessment of reconstructed faces revealed specific sources of information (e.g., affect and skin color) that were successfully reconstructed in ANG. Strikingly, we also found that a model trained on ANG activity patterns during face perception was able to successfully reconstruct an independent set of face images that were held in memory. Together, these findings provide compelling evidence that ANG forms complex, stimulus-specific representations that are reflected in activity patterns evoked during perception and remembering.