Department of Brain Repair and Rehabilitation, University College London, London, UK; Wellcome Trust Centre for Neuroimaging, University College London, London, UK; Facultad de Psicologia, Pontificia Universidad Javeriana, Bogota, Colombia.
Institute of Cognitive Neuroscience, University College London, London, UK.
Cortex. 2018 Sep;106:200-212. doi: 10.1016/j.cortex.2018.06.003. Epub 2018 Jun 23.
We investigated the role of the left temporo-parietal regions in supporting reading abilities of 23 patients with central alexia (CA). For the behavioural data, we employed principal components analysis (PCA), which identified two components: 'reading aloud' and 'reading for meaning'. Voxel-based morphometry of the PCA results showed an association between reading aloud and grey matter density in the left supramarginal gyrus, part of the dorsal visual stream. By contrast, reading for meaning was associated with a large cluster in the left ventral visual stream, from the collateral sulcus to the anterior temporal pole. Most of the peaks were within the group lesion map, indicating that sparing of these areas results in better preservation of reading ability. However, one white matter (WM) cluster in the medial occipitotemporal lobe was outside the lesioned area. A post-hoc test demonstrated that WM density here was equivalent to controls, suggesting that this was not driven by lesion effects. The two likeliest explanations for this correlation are: 1) that pre-morbid, inter-individual differences in brain structure mitigate the effects of CA; 2) that post-morbid practice-based with reading caused compensatory plasticity. We hope to adjudicate between these explanations with longitudinal therapy data collected in this cohort.
我们研究了左颞顶区域在支持 23 名中央性失读症（CA）患者阅读能力中的作用。对于行为数据，我们采用主成分分析（PCA），该分析确定了两个成分：“朗读”和“理解阅读”。基于 PCA 结果的体素形态计量学显示，朗读与左顶下小叶的灰质密度有关，左顶下小叶是背侧视觉流的一部分。相比之下，理解阅读与左腹侧视觉流中从侧副沟到前颞极的一大簇区域有关。大多数峰都在组损伤图内，这表明这些区域的保留会导致更好的阅读能力保留。然而，内侧枕颞叶的一个白质（WM）簇在损伤区域之外。事后检验表明，此处 WM 密度与对照组相当，这表明这不是由损伤效应引起的。这种相关性最有可能的两种解释是：1）在发病前，大脑结构的个体间差异减轻了 CA 的影响；2）发病后的基于阅读的实践引起了代偿性可塑性。我们希望通过在该队列中收集的纵向治疗数据来对这些解释进行裁决。
