Recognition Alters the Spatial Pattern of fMRI Activation in Early Retinotopic Cortex
Recognition Alters the Spatial Pattern of fMRI Activation in Early Retinotopic Cortex
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DOI：
10.1152/jn.00812.2009
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发表时间：
2010-03-01
影响因子：
2.5
通讯作者：
Kanwisher, N.
中科院分区：
文献类型：
--
作者：
Hsieh, P. -J.;Vul, E.;Kanwisher, N.
放大图片作者：Hsieh P-J，Vul E，Kanwisher N.识别改变了早期视网膜皮层fMRI激活的空间模式。神经生理学杂志103：1501-1507，2010年。首次发表于2010年1月13日; doi：10.1152/jn.00812.2009。传统上，早期视网膜皮层被认为包含了图像低层次属性的真实表征，而不是被高层次的解释和意义所浸透。然而，最近的几项研究结果表明，早期视网膜皮层的神经表征不仅反映了图像的感觉特性，而且还反映了图像区域的感知大小和亮度。在这里，我们使用功能性磁共振成像模式分析，以询问是否在早期retinotopic皮层的对象的表征变化时，该对象被识别时，与相同的刺激时，但不承认。我们的数据证实了这一假设：早期视网膜视皮层对一个物体的双色调“穆尼”图像的反应模式与观察者知道双色调图像代表什么时对同一图像的全灰度照片版本的反应更相似。此外，在第二个实验中，高层次的解释实际上会压倒自下而上的刺激信息，因此，早期视网膜皮层对识别出的双色调图像的反应模式更类似于对该刺激的摄影版本的反应，而不是对未识别出的相同双色调图像的反应。我们的研究结果与先前的结果一致，表明感知的大小和亮度影响早期视网膜视皮层的表征，并进一步表明，即使是更高层次的信息-物体身份的知识-也会影响早期视网膜视皮层的对象的表征。
Hsieh P-J, Vul E, Kanwisher N. Recognition alters the spatial pattern of fMRI activation in early retinotopic cortex. J Neurophysiol 103: 1501-1507, 2010. First published January 13, 2010; doi: 10.1152/jn.00812.2009. Early retinotopic cortex has traditionally been viewed as containing a veridical representation of the low-level properties of the image, not imbued by high-level interpretation and meaning. Yet several recent results indicate that neural representations in early retinotopic cortex reflect not just the sensory properties of the image, but also the perceived size and brightness of image regions. Here we used functional magnetic resonance imaging pattern analyses to ask whether the representation of an object in early retinotopic cortex changes when the object is recognized compared with when the same stimulus is presented but not recognized. Our data confirmed this hypothesis: the pattern of response in early retinotopic visual cortex to a two-tone "Mooney" image of an object was more similar to the response to the full grayscale photo version of the same image when observers knew what the two-tone image represented than when they did not. Further, in a second experiment, high-level interpretations actually overrode bottom-up stimulus information, such that the pattern of response in early retinotopic cortex to an identified two-tone image was more similar to the response to the photographic version of that stimulus than it was to the response to the identical two-tone image when it was not identified. Our findings are consistent with prior results indicating that perceived size and brightness affect representations in early retinotopic visual cortex and, further, show that even higher-level information-knowledge of object identity-also affects the representation of an object in early retinotopic cortex.