PDF(Pubmed)
Abstract：
Motor actions, such as reaching or grasping, can be decoded from fMRI activity of early visual cortex (EVC) in sighted humans. This effect can depend on vision or visual imagery, or alternatively, could be driven by mechanisms independent of visual experience. Here, we show that the actions of reaching in different directions can be reliably decoded from fMRI activity of EVC in congenitally blind humans (both sexes). Thus, neither visual experience nor visual imagery is necessary for EVC to represent action-related information. We also demonstrate that, within EVC of blind humans, the accuracy of reach direction decoding is highest in areas typically representing foveal vision and gradually decreases in areas typically representing peripheral vision. We propose that this might indicate the existence of a predictive, hard-wired mechanism of aligning action and visual spaces. This mechanism might send action-related information primarily to the high-resolution foveal visual areas, which are critical for guiding and online correction of motor actions. Finally, we show that, beyond EVC, the decoding of reach direction in blind humans is most accurate in dorsal stream areas known to be critical for visuo-spatial and visuo-motor integration in the sighted. Thus, these areas can develop space and action representations even in the lifelong absence of vision. Overall, our findings in congenitally blind humans match previous research on the action system in the sighted, and suggest that the development of action representations in the human brain might be largely independent of visual experience.SIGNIFICANCE STATEMENT Early visual cortex (EVC) was traditionally thought to process only visual signals from the retina. Recent studies proved this account incomplete, and showed EVC involvement in many activities not directly related to incoming visual information, such as memory, sound, or action processing. Is EVC involved in these activities because of visual imagery? Here, we show robust reach direction representation in EVC of humans born blind. This demonstrates that EVC can represent actions independently of vision and visual imagery. Beyond EVC, we found that reach direction representation in blind humans is strongest in dorsal brain areas, critical for action processing in the sighted. This suggests that the development of action representations in the human brain is largely independent of visual experience.
摘要：
电机动作,如伸手或抓住，可以从有视力的人类早期视觉皮层的功能磁共振成像活动中解码。这种效果可能取决于视觉或视觉图像，或者，可以由独立于视觉体验的机制驱动。这里,我们表明，可以从先天性盲人（两性）的早期视觉皮层的fMRI活动中可靠地解码出到达不同方向的动作。因此，视觉体验和视觉意象对于早期视觉皮层表示与行动相关的信息都不是必需的。我们还证明，在盲人的早期视觉皮层中，到达方向解码的准确度在通常代表中央凹视觉的区域中最高,并且在通常代表周边视觉的区域中逐渐降低。我们认为这可能表明存在一种预测性的，对齐动作和视觉空间的硬连线机制。这种机制可能会将与动作相关的信息主要发送到高分辨率的中央凹视觉区域，这对于指导和在线纠正运动动作至关重要。最后,我们证明，超越早期视觉皮层，盲人到达方向的解码在已知对视觉空间和视觉运动整合至关重要的背流区域中最准确。因此，即使在终身缺乏视力的情况下，这些领域也可以发展空间和行动表现。总的来说,我们在先天性盲人中的发现与先前对有目共睹的行动系统的研究相匹配，并表明人脑中动作表征的发展可能在很大程度上独立于视觉体验。意义陈述传统上认为早期视觉皮层（EVC）仅处理来自视网膜的视觉信号。最近的研究证明这个说法不完整,并显示EVC参与了许多与传入视觉信息不直接相关的活动，比如记忆，声音,或动作处理。EVC参与这些活动是因为视觉图像吗？在这里，我们在出生的盲人的EVC中显示了稳健的到达方向表示。这表明EVC可以独立于视觉和视觉图像来表示动作。超越EVC,我们发现盲人的到达方向表示在背侧大脑区域最强，对于有远见的行动处理至关重要。这表明人脑中动作表征的发展在很大程度上独立于视觉体验。
