Bruno Jennifer Lynn, Zumberge Allison, Manis Franklin R, Lu Zhong-Lin, Goldman Jason G
Department of Psychology, Seeley G Mudd Building, University of Southern California, Los Angeles, CA 90089-1061, USA.
Neuroimage. 2008 Feb 15;39(4):1988-2001. doi: 10.1016/j.neuroimage.2007.10.044. Epub 2007 Nov 12.
The involvement of the left hemisphere occipito-temporal (OT) junction in reading has been established, yet there is current controversy over the region's specificity for reading and the nature of its role in the reading process. Recent neuroimaging findings suggest that the region is sensitive to orthographic familiarity [Kronbichler, M., Bergmann, J., Hutzler, F., Staffen, W., Mair, A., Ladurner, G., Wimmer, H. 2007. Taxi vs. Taksi: on orthographic word recognition in the left ventral occipito-temporal cortex. Journal of Cognitive Neuroscience 19, 1-11], and the present study tested that hypothesis. Using fMRI, the OT region and other regions in the reading network were localized in 28 adult, right-handed participants. The BOLD signal in these regions was measured during a phonological judgment task (i.e., "Does it sound like a word?"). Stimuli included words, pseudohomophones (phonologically familiar yet orthographically unfamiliar), and pseudowords (phonologically and orthographically unfamiliar) that were matched on lexical properties including sublexical orthography. Relative to baseline, BOLD signal in the OT region was greater for pseudohomophones than for words, suggesting that the region is sensitive to orthographic familiarity at the whole-word level. Further contrasts of orthographic frequency within the word condition revealed increased BOLD signal for low- than high-frequency words. Specialization in the OT region for recognition of frequent letter strings may support the development of reading expertise. Additionally, BOLD signal in the OT region correlates positively with reading efficiency, supporting the idea that this region is a skill zone for reading printed words. BOLD signal in the IFG and STG correlates negatively with reading efficiency, indicating that processing effort in these classic phonological regions is inversely related to reading efficiency.
左半球枕颞（OT）交界处与阅读的关联已得到确认，但目前关于该区域对阅读的特异性及其在阅读过程中作用的性质仍存在争议。近期的神经影像学研究结果表明，该区域对正字法熟悉度敏感[克龙比希勒，M.，伯格曼，J.，胡茨勒，F.，斯塔芬，W.，迈尔，A.，拉杜尔纳，G.，维默，H. 2007年。出租车与塔克西：关于左腹侧枕颞叶皮层的正字法单词识别。《认知神经科学杂志》19卷，第1 - 11页]，本研究对这一假设进行了验证。通过功能磁共振成像（fMRI），在28名成年右利手参与者中定位了OT区域以及阅读网络中的其他区域。在一项语音判断任务（即“它听起来像个单词吗？”）过程中测量了这些区域的血氧水平依赖（BOLD）信号。刺激物包括单词、假同音字（语音上熟悉但正字法上不熟悉）和假词（语音和正字法上都不熟悉），它们在包括次词汇正字法在内的词汇属性上进行了匹配。相对于基线，OT区域中假同音字的BOLD信号比单词的更大，这表明该区域在整个单词层面上对正字法熟悉度敏感。在单词条件下对正字法频率的进一步对比显示，低频单词的BOLD信号高于高频单词。OT区域对频繁字母串识别的专门化可能有助于阅读技能的发展。此外，OT区域的BOLD信号与阅读效率呈正相关，支持了该区域是阅读印刷单词的技能区这一观点。额下回（IFG）和颞上回（STG）的BOLD信号与阅读效率呈负相关，表明这些经典语音区域的处理努力与阅读效率呈负相关。
