State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875, China.
J Neurosci. 2012 Aug 29;32(35):12277-83. doi: 10.1523/JNEUROSCI.1874-12.2012.
Functional magnetic resonance imaging (fMRI) studies on humans have identified a region in the left middle fusiform gyrus consistently activated by written words. This region is called the visual word form area (VWFA). Recently, a hypothesis, called the interactive account, is proposed that to effectively analyze the bottom-up visual properties of words, the VWFA receives predictive feedback from higher-order regions engaged in processing sounds, meanings, or actions associated with words. Further, this top-down influence on the VWFA is independent of stimulus formats. To test this hypothesis, we used fMRI to examine whether a symbolic nonword object (e.g., the Eiffel Tower) intended to represent something other than itself (i.e., Paris) could activate the VWFA. We found that scenes associated with symbolic meanings elicited a higher VWFA response than those not associated with symbolic meanings, and such top-down modulation on the VWFA can be established through short-term associative learning, even across modalities. In addition, the magnitude of the symbolic effect observed in the VWFA was positively correlated with the subjective experience on the strength of symbol-referent association across individuals. Therefore, the VWFA is likely a neural substrate for the interaction of the top-down processing of symbolic meanings with the analysis of bottom-up visual properties of sensory inputs, making the VWFA the location where the symbolic meaning of both words and nonword objects is represented.
功能磁共振成像（fMRI）研究表明，人类大脑左中部梭状回的一个区域会被书面文字持续激活。这个区域被称为视觉词形区（VWFA）。最近，有人提出了一种假设，即交互作用假说，认为要有效地分析单词的自上而下的视觉属性，VWFA 会从参与处理声音、意义或与单词相关动作的更高阶区域接收到预测性反馈。此外，这种对 VWFA 的自上而下的影响与刺激格式无关。为了验证这一假设，我们使用 fMRI 检查了一个符号非单词物体（例如埃菲尔铁塔）是否可以激活 VWFA，该物体旨在代表其他东西（即巴黎）而不是自身。我们发现，与符号意义相关的场景比与符号意义不相关的场景引起了更高的 VWFA 反应，并且这种对 VWFA 的自上而下的调制可以通过短期联想学习建立，即使在不同的模式下也是如此。此外，在 VWFA 中观察到的符号效应的幅度与个体之间符号参照关联强度的主观体验呈正相关。因此，VWFA 可能是自上而下处理符号意义与分析感觉输入的自下而上视觉属性相互作用的神经基础，使 VWFA 成为单词和非单词物体的符号意义所在的位置。
