An investigation of cross-modal plasticity of effective connectivity in the blind by dynamic causal modeling of functional MRI data
An investigation of cross-modal plasticity of effective connectivity in the blind by dynamic causal modeling of functional MRI data
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DOI：
10.1016/j.neures.2009.06.014
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发表时间：
2009-10-01
影响因子：
2.9
通讯作者：
Sadato, Norihiro
中科院分区：
文献类型：
--
作者：
Fujii, Takeshi;Tanabe, Hiroki C.;Sadato, Norihiro
为了研究盲人初级体感区（S1）和纹状皮层（V1）之间的连通性，我们对15名盲人（9名早发性和6名晚发性）和24名视力正常的受试者用右手进行触觉盲文辨别任务时获得的功能性MRI进行动态因果建模。从腹侧或背侧通路中选择5个感兴趣的区域：左S1、前顶叶内沟（aIPS）、枕上回（SOG）、枕下回（IOG）和V1。贝叶斯模型比较表明，V1和SI之间无直接连接的皮质-皮质反馈通路模型比有直接连接的模型表现更好。在盲人中，aIPS-SOG和aIPS-IOG的基线连通性及其特异性调节是阳性和双向的，而在视力正常的人中是阴性的。因此，由于触觉输入的竞争性转移，视觉剥夺可能引起视觉皮层区域的重组。早期失明比晚期失明在背侧通路（aIPS-V1至SOG）和SOG- iog双向上表现出更强的连通性。盲试任务绩效与SOG-V1和SOG-IOG基线连通性呈正相关。因此，背侧视觉区参与了盲人V1从视觉信息加工到触觉信息加工的功能转移。(C) 2009爱思唯尔爱尔兰有限公司和日本神经科学学会。版权所有。
To investigate connectivity between primary somatosensory area (S1) and striate cortex (V1) in the blind, we used dynamic causal modeling of functional MRI acquired while 15 blind (9 early-onset and 6 late-onset) and 24 sighted subjects performed a tactile Braille discrimination task with their right hand. Five regions of interest were selected from either the ventral or dorsal pathways: left S1, anterior intraparietal sulcus (aIPS), superior occipital gyrus (SOG), inferior occipital gyrus (IOG), and V1. Bayesian model comparison showed that a cortico-cortical feedback pathway model without direct connections between V1 and SI performed better than that with direct connections. In the blind, baseline connectivity and its discrimination-specific modulation in aIPS-SOG and aIPS-IOG were positive and bidirectional, while they were negative in the sighted. Thus visual deprivation may induce reorganization of the visual cortical areas due to the competitive shift for tactile inputs. The early blind showed stronger connectivity than the late blind in the dorsal pathway (aIPS-V1 through SOG) and in SOG-IOG bidirectionally. Task performance positively correlated with baseline connectivity of SOG-V1 and SOG-IOG across blind subjects. Therefore, dorsal visual regions are involved in the functional shift in V1 from visual to tactile information processing in blind subjects. (C) 2009 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.