A dynamic causal modeling analysis of the effective connectivities underlying top-down letter processing

NEUROPSYCHOLOGIA

卷:49

Article

Liu, Jiangang²  Li, Jun³  Rieth, Cory A.⁴  Huber, David E.⁴  Tian, Jie^1,3  Lee, Kang^4,5 

[1] Chinese Acad Sci, Inst Automat, Beijing 100190, Peoples R China

[2] Beijing Jiaotong Univ, Sch Comp & Informat Technol, Dept Biomed Engn, Beijing 100044, Peoples R China

[3] Xidian Univ, Sch Life Sci & Technol, Xian 710071, Peoples R China

[4] Univ Calif San Diego, San Diego, CA 92103 USA

[5] Univ Toronto, Toronto, ON M5S 1A1, Canada

关键词: Letter processing;    Word processing;    Top-down processing;    fMRI;    Dynamic causal modeling;   

DOI  :  10.1016/j.neuropsychologia.2011.01.011

来源: Elsevier

【 摘 要 】

The present study employed dynamic causal modeling to investigate the effective functional connectivity between regions of the neural network involved in top-down letter processing. We used an illusory letter detection paradigm in which participants detected letters while viewing pure noise images. When participants detected letters, the response of the right middle occipital gyrus (MOG) in the visual cortex was enhanced by increased feed-backward connectivity from the left inferior frontal gyrus (IFG). In addition, illusory letter detection increased feed-forward connectivity from the right MOG to the left inferior parietal lobules. Originating in the left IFG, this top-down letter processing network may facilitate the detection of letters by activating letter processing areas within the visual cortex. This activation in turns may highlight the visual features of letters and send letter information to activate the associated phonological representations in the identified parietal region. (C) 2011 Elsevier Ltd. All rights reserved.

【 授权许可】

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