Differential sensitivity to words and shapes in ventral occipito-temporal cortex
Differential sensitivity to words and shapes in ventral occipito-temporal cortex
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DOI：
10.1093/cercor/bhl071
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发表时间：
2007-07-01
期刊：
影响因子：
3.7
通讯作者：
Wandell, Brian A.
中科院分区：
文献类型：
--
作者：
Ben-Shachar, Michal;Dougherty, Robert F.;Wandell, Brian A.
形状信息的有效提取对于熟练的阅读是必不可少的，但是形状分析的皮层机制在单词阅读中的作用还没有很好的理解。我们研究了皮质的书面文字的反应，而参数变化的视觉噪声施加到字刺激的量。只有少数区域沿着腹侧表面，皮质反应增加了字的可见性。我们发现，持续增加的反应，在双边后枕颞沟（POTS），在解剖位置，密切配合的“视觉词形区”。在其他皮层区域，如V1，反应保持不变，无论噪音水平。我们进行了3个额外的测试，以评估书面文字处理的pOTS响应的功能专业化。我们询问pOTS反应是否1）左偏，2）对单词比线条画或假字体更敏感，3）对单词的视觉疝区不变，而不是其他刺激。我们发现，左和右pOTS响应函数对单词的敏感性最高，对线条画的敏感性居中，对错误字体的敏感性最低。视觉hernefield不变性是类似的文字和线条画。这些结果表明，左和右pOTS都参与了形状加工，提高了加工视觉单词形式的效率。
Efficient extraction of shape information is essential for proficient reading but the role of cortical mechanisms of shape analysis in word reading is not well understood. We studied cortical responses to written words while parametrically varying the amount of visual noise applied to the word stimuli. In only a few regions along the ventral surface, cortical responses increased with word visibility. We found consistently increasing responses in bilateral posterior occipito-temporal sulcus (pOTS), at an anatomical location that closely matches the "visual word form area". In other cortical regions, such as V1, responses remained constant regardless of the noise level. We performed 3 additional tests to assess the functional specialization of pOTS responses for written word processing. We asked whether pOTS responses are 1) left lateralized, 2) more sensitive to words than to line drawings or false fonts, and 3) invariant for visual hernifield of words but not other stimuli. We found that left and right pOTS response functions both had highest sensitivity for words, intermediate for line drawings, and lowest for false fonts. Visual hernifield invariance was similar for words and line drawings. These results suggest that left and right pOTS are both involved in shape processing, with enhanced efficiency for processing visual word forms.