Although the fine-grained features of topographic maps in the somatosensory cortex can be shaped by everyday experience, it is unknown whether behavior can support the expression of somatotopic maps where they do not typically occur. Unlike the fingers, represented in all primates, individuated toe maps have only been found in non-human primates. Using 1-mm resolution fMRI, we identify organized toe maps in two individuals born without either upper limb who use their feet to substitute missing hand function and even support their profession as foot artists. We demonstrate that the ordering and structure of the artists' toe representation mimics typical hand representation. We further reveal "hand-like" features of activity patterns, not only in the foot area but also similarly in the missing hand area. We suggest humans may have an innate capacity for forming additional topographic maps that can be expressed with appropriate experience.

中文翻译：

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极端脚用户中的有组织的脚趾图。

尽管可以通过日常经验来塑造体感皮层中地形图的细粒度特征，但是尚不清楚行为是否可以支持通常不发生的体位图表达。与在所有灵长类动物中代表的手指不同，仅在非人类灵长类动物中发现了个性化的脚趾图。使用1毫米分辨率的功能磁共振成像，我们可以识别出两个没有上肢出生的人的有组织的脚趾图，这两个人的双脚都用脚代替了缺失的手功能，甚至支持了他们作为足艺师的职业。我们证明了艺术家脚趾表示的顺序和结构模仿了典型的手部表示。我们进一步揭示了活动模式的“手状”特征，不仅在脚部区域，而且在缺失的手部区域也类似。