Xue Gui, Chen Chuansheng, Jin Zhen, Dong Qi
FPR-UCLA Center for Culture, Brain, and Development, University of California, Los Angeles, CA 90095-1563, USA.
Neuroimage. 2006 Jul 1;31(3):1315-26. doi: 10.1016/j.neuroimage.2005.11.055. Epub 2006 Apr 27.
The significant role of the left midfusiform cortex in reading found in recent neuroimaging studies has led to the visual word form area (VWFA) hypothesis. This hypothesis suggests that years of experience reading native language change the visual expertise of this region to be especially sensitive to the visual form of native language. The present study aimed at testing this hypothesis by exploring the role of language experience in shaping the fusiform activation. We designed a logographic artificial language (LAL) using the visual form and pronunciation of Korean Hangul characters (but their correspondence was shuffled) and assigning arbitrary meanings to these characters. Twelve native Chinese Mandarin speakers (6 male and 6 female, 18 to 21 years old) with no prior knowledge of Korean language were trained in the visual form of these characters for 2 weeks, followed by 2 weeks each of phonological and semantic training. Behavioral data indicated that training was effective in increasing the efficiency of visual form processing and establishing the connections among visual form, sounds, and meanings. Imaging data indicated that at the pre-training stage, subjects showed stronger activation in the fusiform regions for LAL than for Chinese across both one-back visual matching task and the passive viewing task. Visual form training significantly decreased the activation of bilateral fusiform cortex and the left inferior occipital cortex, whereas phonological training increased activation in these regions, and the right fusiform remained more active after semantic training. Increased activations after phonological and semantic training were also evident in other regions involved in language processing. These findings thus do not seem to be consistent with the visual-expertise-induced-sensitivity hypothesis about fusiform regions. Instead, our results suggest that visual familiarity, phonological processing, and semantic processing all make significant but different contributions to shaping the fusiform activation.
近期神经影像学研究发现左侧梭状回中部皮质在阅读中发挥着重要作用，这引发了视觉词形区（VWFA）假说。该假说认为，多年的母语阅读经验改变了该区域的视觉专长，使其对母语的视觉形式格外敏感。本研究旨在通过探究语言经验在塑造梭状回激活中的作用来验证这一假说。我们设计了一种表意人工语言（LAL），它采用了韩语谚文字母的视觉形式和发音（但字母对应关系被打乱），并为这些字符赋予了任意含义。12名没有韩语基础的中国普通话母语者（6名男性和6名女性，年龄在18至21岁之间）接受了为期2周的这些字符视觉形式训练，随后分别进行了为期2周的语音和语义训练。行为数据表明，训练有效地提高了视觉形式处理的效率，并建立了视觉形式、声音和意义之间的联系。成像数据表明，在训练前阶段，在单背视觉匹配任务和被动观看任务中，与中文相比，受试者在梭状回区域对LAL的激活更强。视觉形式训练显著降低了双侧梭状回皮质和左侧枕下回的激活，而语音训练增加了这些区域的激活，语义训练后右侧梭状回仍更活跃。语音和语义训练后激活增加在其他参与语言处理的区域也很明显。因此，这些发现似乎与关于梭状回区域的视觉专长诱导敏感性假说不一致。相反，我们的结果表明，视觉熟悉度、语音处理和语义处理在塑造梭状回激活方面都做出了重大但不同的贡献。
