Embedded word priming elicits enhanced fMRI responses in the visual word form area

Lexical embedding is common in all languages and elicits mutual orthographic interference between an embedded word and its carrier. The neural basis of such interference remains unknown. We employed a novel fMRI prime-target embedded word paradigm to test for involvement of a visual word form area (VWFA) in left ventral occipitotemporal cortex in co-activation of embedded words and their carriers. Based on the results of related fMRI studies we predicted either enhancement or suppression of fMRI responses to embedded words initially viewed as primes, and repeated in the context of target carrier words. Our results clearly showed enhancement of fMRI responses in the VWFA to embedded-carrier word pairs as compared to unrelated prime-target pairs. In contrast to non-visual language-related areas (e.g., left inferior frontal gyrus), enhanced fMRI responses did not occur in the VWFA when embedded-carrier word pairs were restricted to the left visual hemifield. Our finding of fMRI enhancement in the VWFA is novel evidence of its involvement in representational rivalry between orthographically similar words, and the co-activation of embedded words and their carriers.词汇嵌入在各类语言中普遍存在，且会引发嵌入词与其载体词之间的相互正字法干扰。此类干扰的神经基础目前仍不明晰。我们采用了一种全新的功能磁共振成像（fMRI）启动-靶标嵌入词范式，以验证左侧腹侧枕颞皮层内的视觉词形区（visual word form area，VWFA）是否参与了嵌入词及其载体词的共同激活过程。基于相关功能磁共振成像研究的结果，我们预设：当作为启动项的嵌入词在靶标载体词的语境中重复出现时，其功能磁共振成像响应会出现增强或抑制。我们的研究结果清晰显示：相较于无关启动-靶标词对，视觉词形区对嵌入-载体词对的功能磁共振成像响应显著增强。与非视觉语言相关脑区（如左侧额下回）不同，当嵌入-载体词对仅呈现于左侧视觉半野时，视觉词形区并未出现响应增强的现象。我们在视觉词形区内观测到的功能磁共振成像响应增强现象，为其参与正字法相似词汇间的表征竞争以及嵌入词与载体词的共同激活过程，提供了全新的实验证据。