Inuggi Alberto, Pichiecchio Anna, Ciacchini Benedetta, Signorini Sabrina, Morelli Federica, Gori Monica
Unit for Visually Impaired People (U-VIP), Istituto Italiano di Tecnologia, 16152 Genova, Italy.
Department of Brain and Behavioural Neuroscience, University of Pavia, 27100 Pavia, Italy.
Cereb Cortex Commun. 2020 Oct 9;1(1):tgaa071. doi: 10.1093/texcom/tgaa071. eCollection 2020.
It has been shown that the total or partial lack of visual experience is associated with a plastic reorganization at the brain level, more prominent in congenital blind. Cortical thickness (CT) studies, to date involving only adult subjects, showed that only congenital blind have a thicker cortex than age-matched sighted population while late blind do not. This was explained as a deviation from the physiological mechanism of initial neural growth followed by a pruning mechanism that, in congenital blind children, might be reduced by their visual deprivation, thus determining a thicker cortex. Since those studies involved only adults, it is unknown when these changes may appear and whether they are related to impairment degree. To address this question, we compared the CT among 28 children, from 2 to 12 years, with congenital visual impairments of different degree and an age-matched sighted population. Vertex-wise analysis showed that blind children, but not low vision one, had a thicker cortical surface in few clusters located in occipital, superior parietal, anterior-cingular, orbito-frontal, and mesial precentral regions. Our data suggest that the effect of visual impairment on determining thicker cortex is an early phenomenon, is multisystemic, and occurs only when blindness is almost complete.
研究表明，视觉体验的全部或部分缺失与大脑层面的可塑性重组有关，这在先天性失明者中更为显著。迄今为止，皮层厚度（CT）研究仅涉及成年受试者，结果显示只有先天性失明者的皮层比年龄匹配的视力正常人群更厚，而迟发性失明者则不然。这被解释为偏离了最初神经生长的生理机制，随后是一种修剪机制，在先天性失明儿童中，这种机制可能因视觉剥夺而减弱，从而导致皮层更厚。由于这些研究仅涉及成年人，尚不清楚这些变化何时会出现以及它们是否与损伤程度有关。为了解决这个问题，我们比较了28名2至12岁不同程度先天性视力障碍儿童与年龄匹配的视力正常人群的CT。逐顶点分析表明，失明儿童（而非低视力儿童）在位于枕叶、顶上叶、前扣带回、眶额叶和中央前回中部的少数簇中有较厚的皮层表面。我们的数据表明，视力障碍对皮层增厚的影响是一种早期现象，是多系统的，并且仅在几乎完全失明时才会出现。
