Department of Psychological Sciences, Birkbeck, University of London, London WC1E 7HX, UK; School of Psychology, University of Kent, Canterbury CT2 7NP, UK.
Department of Psychological Sciences, Birkbeck, University of London, London WC1E 7HX, UK.
Neuroimage. 2021 Apr 1;229:117730. doi: 10.1016/j.neuroimage.2021.117730. Epub 2021 Jan 14.
Psychophysical experiments have demonstrated large and highly systematic perceptual distortions of tactile space. Such a space can be referred to our experience of the spatial organisation of objects, at representational level, through touch, in analogy with the familiar concept of visual space. We investigated the neural basis of tactile space by analysing activity patterns induced by tactile stimulation of nine points on a 3 × 3 square grid on the hand dorsum using functional magnetic resonance imaging. We used a searchlight approach within pre-defined regions of interests to compute the pairwise Euclidean distances between the activity patterns elicited by tactile stimulation. Then, we used multidimensional scaling to reconstruct tactile space at the neural level and compare it with skin space at the perceptual level. Our reconstructions of the shape of skin space in contralateral primary somatosensory and motor cortices reveal that it is distorted in a way that matches the perceptual shape of skin space. This suggests that early sensorimotor areas critically contribute to the distorted internal representation of tactile space on the hand dorsum.
心理物理学实验已经证明了触觉空间的大而系统的感知扭曲。这样的空间可以通过触摸在表象层面上被称为我们对物体空间组织的体验，类似于我们熟悉的视觉空间概念。我们通过分析使用功能磁共振成像对手背 3×3 正方形网格上的九个点进行触觉刺激所引起的活动模式，来研究触觉空间的神经基础。我们使用预定义的兴趣区域内的搜索灯方法，计算由触觉刺激引起的活动模式之间的两两欧几里得距离。然后，我们使用多维标度法在神经水平上重建触觉空间，并将其与感知水平上的皮肤空间进行比较。我们在对侧初级体感和运动皮层中对皮肤空间形状的重建表明，它的扭曲方式与皮肤空间的感知形状相匹配。这表明早期的感觉运动区域对手背触觉空间的扭曲内部表示具有重要贡献。
