Center for Advanced Study of Language, University of Maryland, College Park, MD, USA; Department of Psychological & Brain Sciences, University of Louisville, Louisville, KY, USA.
Cortex. 2013 Oct;49(9):2307-21. doi: 10.1016/j.cortex.2013.03.008. Epub 2013 Apr 10.
Two brain regions with established roles in reading are the posterior middle temporal gyrus and the posterior fusiform gyrus (FG). Lesion studies have also suggested that the region located between them, the posterior inferior temporal gyrus (pITG), plays a central role in word recognition. However, these lesion results could reflect disconnection effects since neuroimaging studies have not reported consistent lexicality effects in pITG. Here we tested whether these reported pITG lesion effects are due to disconnection effects or not using parallel Event-related Potentials (ERP)/functional magnetic resonance imaging (fMRI) studies. We predicted that the Recognition Potential (RP), a left-lateralized ERP negativity that peaks at about 200-250 msec, might be the electrophysiological correlate of pITG activity and that conditions that evoke the RP (perceptual degradation) might therefore also evoke pITG activity. In Experiment 1, twenty-three participants performed a lexical decision task (temporally flanked by supraliminal masks) while having high-density 129-channel ERP data collected. In Experiment 2, a separate group of fifteen participants underwent the same task while having fMRI data collected in a 3T scanner. Examination of the ERP data suggested that a canonical RP effect was produced. The strongest corresponding effect in the fMRI data was in the vicinity of the pITG. In addition, results indicated stimulus-dependent functional connectivity between pITG and a region of the posterior FG near the Visual Word Form Area (VWFA) during word compared to nonword processing. These results provide convergent spatiotemporal evidence that the pITG contributes to early lexical access through interaction with the VWFA.
两个在阅读中具有明确作用的大脑区域是后颞中回和后梭状回（FG）。损伤研究还表明，它们之间的区域，即下颞后回（pITG），在单词识别中起着核心作用。然而，这些损伤结果可能反映了连接中断效应，因为神经影像学研究并未在 pITG 中报告一致的词汇效应。在这里，我们使用平行的事件相关电位（ERP）/功能磁共振成像（fMRI）研究来测试这些报告的 pITG 损伤效应是否是由于连接中断效应引起的。我们预测，识别电位（RP），即大约在 200-250 毫秒时出现的左偏 ERP 负性，可能是 pITG 活动的电生理相关物，并且因此可能引发 RP （感知退化）的条件也可能引发 pITG 活动。在实验 1 中，23 名参与者在进行词汇判断任务（在超阈掩蔽物的时间限制下）的同时，采集高密度 129 通道 ERP 数据。在实验 2 中，另一组 15 名参与者在 3T 扫描仪中进行了相同的任务，同时采集 fMRI 数据。对 ERP 数据的检查表明产生了典型的 RP 效应。在 fMRI 数据中最强的对应效应位于 pITG 附近。此外，结果表明，与非词处理相比，在词处理期间，pITG 与后 FG 中接近视觉词形区（VWFA）的区域之间存在刺激依赖性功能连接。这些结果提供了具有时空一致性的证据，表明 pITG 通过与 VWFA 的相互作用，有助于早期词汇访问。
