Cardin Velia, Smittenaar Rebecca C, Orfanidou Eleni, Rönnberg Jerker, Capek Cheryl M, Rudner Mary, Woll Bencie
Deafness, Cognition and Language Research Centre, 49 Gordon Square, University College London, London WC1H 0BT, UK; Linnaeus Centre HEAD, Swedish Institute for Disability Research, Department of Behavioural Sciences and Learning, Linköping University, Sweden.
Experimental Psychology, 26 Bedford Way, University College London, London WC1H 0AP, UK.
Neuroimage. 2016 Jan 1;124(Pt A):96-106. doi: 10.1016/j.neuroimage.2015.08.073. Epub 2015 Sep 5.
Sensory cortices undergo crossmodal reorganisation as a consequence of sensory deprivation. Congenital deafness in humans represents a particular case with respect to other types of sensory deprivation, because cortical reorganisation is not only a consequence of auditory deprivation, but also of language-driven mechanisms. Visual crossmodal plasticity has been found in secondary auditory cortices of deaf individuals, but it is still unclear if reorganisation also takes place in primary auditory areas, and how this relates to language modality and auditory deprivation. Here, we dissociated the effects of language modality and auditory deprivation on crossmodal plasticity in Heschl's gyrus as a whole, and in cytoarchitectonic region Te1.0 (likely to contain the core auditory cortex). Using fMRI, we measured the BOLD response to viewing sign language in congenitally or early deaf individuals with and without sign language knowledge, and in hearing controls. Results show that differences between hearing and deaf individuals are due to a reduction in activation caused by visual stimulation in the hearing group, which is more significant in Te1.0 than in Heschl's gyrus as a whole. Furthermore, differences between deaf and hearing groups are due to auditory deprivation, and there is no evidence that the modality of language used by deaf individuals contributes to crossmodal plasticity in Heschl's gyrus.
感觉皮层会因感觉剥夺而发生跨模态重组。人类先天性耳聋相对于其他类型的感觉剥夺而言是一种特殊情况，因为皮层重组不仅是听觉剥夺的结果，也是语言驱动机制的结果。在失聪个体的二级听觉皮层中发现了视觉跨模态可塑性，但尚不清楚初级听觉区域是否也会发生重组，以及这与语言模态和听觉剥夺有何关系。在这里，我们区分了语言模态和听觉剥夺对整个颞横回以及细胞构筑区域Te1.0（可能包含核心听觉皮层）中跨模态可塑性的影响。我们使用功能磁共振成像技术，测量了先天性或早期失聪且有或没有手语知识的个体以及听力正常对照组在观看手语时的血氧水平依赖（BOLD）反应。结果表明，听力正常个体与失聪个体之间的差异是由于听力组中视觉刺激引起的激活减少所致，这在Te1.0区域比在整个颞横回中更为显著。此外，失聪组与听力正常组之间的差异是由于听觉剥夺造成的，没有证据表明失聪个体所使用的语言模态会对颞横回中的跨模态可塑性产生影响。
