Cross-modal plasticity preserves functional specialization in posterior parietal cortex.
Cross-modal plasticity preserves functional specialization in posterior parietal cortex.
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DOI：
10.1093/cercor/bhs340
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发表时间：
2014-02
期刊：
影响因子：
3.7
通讯作者：
A. Lingnau;L. Strnad;Chenxi He;Sara Fabbri;Zaizhu Han;Y. Bi;A. Caramazza
中科院分区：
文献类型：
--
作者：
A. Lingnau;L. Strnad;Chenxi He;Sara Fabbri;Zaizhu Han;Y. Bi;A. Caramazza
在先天失明的个体中，大脑中通常与视觉处理密切相关的许多区域被用于各种非视觉的感觉和认知任务（Rauschecker 1995; Pascual-Leone et al. 2005）。这种现象——跨模态可塑性——已经被广泛记录，但是决定跨模态变化在哪里以及如何发生的原则仍然知之甚少（Bavelier和Neville 2002）。在这里，我们评估了跨模态可塑性尊重区域执行的计算类型的假设，即使它改变了执行它们的输入的模态（Pascual-Leone和Hamilton 2001）。我们比较了正常和先天失明参与者在本体感觉引导下的fMRI信号。我们发现，顶骨-枕部触达相关区域保留了它们的功能角色——编码触达目标的空间位置——即使该区域的主导模式从视觉输入转变为非视觉输入。这表明，一个区域的计算作用，独立于处理模式，共同决定其潜在的跨模式招募。我们的研究结果表明，即使在视觉运动皮层区域，即早期视觉皮层和其他传统视觉区域之外，功能特性的保存也可以作为跨模态可塑性的指导原则。
In congenitally blind individuals, many regions of the brain that are typically heavily involved in visual processing are recruited for a variety of nonvisual sensory and cognitive tasks (Rauschecker 1995; Pascual-Leone et al. 2005). This phenomenon-cross-modal plasticity-has been widely documented, but the principles that determine where and how cross-modal changes occur remain poorly understood (Bavelier and Neville 2002). Here, we evaluate the hypothesis that cross-modal plasticity respects the type of computations performed by a region, even as it changes the modality of the inputs over which they are carried out (Pascual-Leone and Hamilton 2001). We compared the fMRI signal in sighted and congenitally blind participants during proprioceptively guided reaching. We show that parietooccipital reach-related regions retain their functional role-encoding of the spatial position of the reach target-even as the dominant modality in this region changes from visual to nonvisual inputs. This suggests that the computational role of a region, independently of the processing modality, codetermines its potential cross-modal recruitment. Our findings demonstrate that preservation of functional properties can serve as a guiding principle for cross-modal plasticity even in visuomotor cortical regions, i.e. beyond the early visual cortex and other traditional visual areas.