Menghini Deny, Hagberg Gisela E, Petrosini Laura, Bozzali Marco, Macaluso Emiliano, Caltagirone Carlo, Vicari Stefano
Child Neuropsychiatry Unit, Department of Neuroscience, IRCCS, Children's Hospital Bambino Gesù, Rome, Italy.
Ann N Y Acad Sci. 2008 Dec;1145:212-21. doi: 10.1196/annals.1416.010.
Several neuroimaging studies in developmental dyslexia (DD) have mainly focused on brain regions subserving phonological processes. However, additional deficits characterize subjects with DD, such as an impairment of visual and rapid stimuli processing and deficits in implicit learning (IL). Little is known about structural abnormalities in brain regions not directly related to phonology and reading processes. The aim of this study was to investigate, using voxel-based morphometry, whether subjects with DD exhibit any structural grey matter (GM) abnormalities in regions that have previously shown abnormal functional magnetic resonance imaging (fMRI) activation during an IL task. Significantly smaller GM volumes were found in the right posterior superior parietal lobule and precuneus and in the right supplementary motor area (SMA) of subjects with DD compared to controls. Moreover, a larger GM volume in parietal cortex was associated with an increase of IL effect in controls but not in subjects with DD. These structural abnormalities are consistent with functional changes and reinforce the hypothesis that an impairment of IL might play a relevant role in learning to read.
多项针对发育性阅读障碍（DD）的神经影像学研究主要聚焦于支持语音处理的脑区。然而，DD患者还存在其他缺陷，比如视觉和快速刺激处理受损以及内隐学习（IL）缺陷。对于与语音和阅读过程无直接关联的脑区结构异常，我们知之甚少。本研究的目的是使用基于体素的形态测量法，探究DD患者在先前IL任务期间显示出异常功能磁共振成像（fMRI）激活的区域是否存在任何结构性灰质（GM）异常。与对照组相比，DD患者右侧后顶上小叶、楔前叶以及右侧辅助运动区（SMA）的GM体积显著更小。此外，顶叶皮质中较大的GM体积与对照组IL效应的增加相关，但与DD患者无关。这些结构异常与功能变化一致，并强化了IL受损可能在阅读学习中起相关作用的假说。
