Cortical activity to vibrotactile stimulation: An fMRI study in blind and sighted individuals
Cortical activity to vibrotactile stimulation: An fMRI study in blind and sighted individuals
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DOI：
10.1002/hbm.20064
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发表时间：
2004-12-01
影响因子：
4.8
通讯作者：
McLaren, DG
中科院分区：
文献类型：
--
作者：
Burton, H;Sinclair, RJ;McLaren, DG
盲人在阅读盲文时会出现视觉皮层活动。我们研究了这种跨模态激活是否反映了独立于语言的处理体感刺激，通过识别皮层活动在一个回振动触觉匹配任务。三组人（视力正常者、早发性失明者和晚发性失明者[>12岁]）检测传递到右手食指的成对振动（25和100 Hz）的频率是否不同。三个连续的成对振动，然后是无刺激间隔，在一个长期的事件相关设计。固定效应平均z分数分析显示整个视皮层的活动增加，其中主要限于中央凹和旁视皮层偏心。早期失明显示出最广泛的活动分布。晚期失明主要在相似的区域表现出活动，但随着失明年龄的增长，反应幅度逐渐下降。三个有视力的人有阈上活动的V1，但在视觉皮层其他地方的负反应。混合效应方差分析证实了定义区域（V1、V3、V4 v、V7、V4 v和MT）的组间差异。这些结果表明，跨通道适应触觉刺激的视觉皮层独立的语言过程。所有组的左侧初级（S1）和双侧第二躯体感觉区的活动均有所增加，但整个感觉运动皮质的组间反应幅度没有差异。早期盲显示最大的空间范围的S1活动。盲人参与者在前顶内沟和缘上回有更广泛的双侧活动。盲文阅读中触摸的广泛使用可能是阅读手指表示中观察到的S1扩展的基础。此外，学习注意触摸可以解释类似的扩大顶叶触觉注意区域。(C)2004 Wiley-Liss，Inc.
Blind individuals show visual cortex activity during Braille reading. We examined whether such cross-modal activations reflect processing somatosensory stimuli independent of language by identifying cortical activity during a one-back vibrotactile matching task. Three groups (sighted, early-onset, and late-onset [>12 years] blind) detected whether paired vibrations (25 and 100 Hz), delivered to the right index finger, differed in frequency. Three successive paired vibrations, followed by a no-stimulation interval, were presented in a long event-related design. A fixed effects average z-score analysis showed increased activity throughout the visuotopic visual cortex, where it was mostly restricted to foveal and parafoveal eccentricities. Early blind showed the most extensive distribution of activity. Late blind exhibited activity mostly in similar regions but with declining response magnitudes with age of blindness onset. Three sighted individuals had suprathreshold activity in V1 but negative responses elsewhere in visual cortex. Mixed effects ANOVA confirmed group distinctions in defined regions (V1, V3, V4v, V7, LOC, and MT). These results suggest cross-modal adaptation to tactile stimulation in visual cortex independent of language processes. All groups showed increased activity in left primary (S1) and bilateral second somatosensory areas, but without response magnitude differences between groups throughout sensorimotor cortex. Early blind showed the greatest spatial extent of S1 activity. Blind participants had more extensive bilateral activity in anterior intraparietal sulcus and supramarginal gyrus. Extensive usage of touch in Braille reading may underlie observed S1 expansions in the reading finger representation. In addition, learned attentiveness to touch may explain similar expansion of parietal tactile attention regions. (C) 2004 Wiley-Liss, Inc.