A typical participation of visual cortex during word processing in autism:: An fMRI study of semantic decision
A typical participation of visual cortex during word processing in autism:: An fMRI study of semantic decision
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DOI：
10.1016/j.neuropsychologia.2007.01.008
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发表时间：
2007-01-01
期刊：
影响因子：
2.6
通讯作者：
Mueller, Ralph-Axel
中科院分区：
文献类型：
--
作者：
Gaffrey, Michael S.;Kleinhans, Natalia M.;Mueller, Ralph-Axel
语言延迟和障碍是自闭症的显著特征。更具体地说，有证据表明自闭症中存在非典型的语义组织，但大脑功能的相关性还没有得到很好的理解。目前的研究使用功能磁共振成像检查激活与语义类别决策。10名高功能自闭症谱系障碍男性和10名健康对照组在性别、利手、年龄和非语言智商方面进行了研究。参与者通过按钮按下响应表示视觉呈现的单词是否属于目标类别（工具，颜色，感觉）。控制条件要求在无法发音的字母串中检测目标字母。在对照组中，左侧额下回（Brodmann区44和45）的语义决策被发现显着激活。自闭症组的相应激活更为有限，在左下额叶45和47区有较小的集群。然而，与对照组相比，自闭症患者的双侧纹外视皮层（区域18和19）的激活程度明显更高，这与语义任务中的错误数量更多相关。我们的研究结果表明，在语义决策过程中的感知组件（可能是视觉图像）的重要作用，与以往的证据不典型的词汇语义表现自闭症。在类似的研究结果，从年轻的典型发展中国家的儿童，我们的研究结果表明，一个不成熟的模式与效率低下的处理，大概是由于非典型的经验嵌入的单词习得自闭症。(c)2007爱思唯尔有限公司保留所有权利。
Language delay and impairment are salient features of autism. More specifically, there is evidence of atypical semantic organization in autism, but the functional brain correlates are not well understood. The current study used functional MRI to examine activation associated with semantic category decision. Ten high-functioning men with autism spectrum disorder and 10 healthy control subjects matched for gender, handedness, age, and nonverbal IQ were studied. Participants indicated via button press response whether visually presented words belonged to a target category (tools, colors, feelings). The control condition required target letter detection in unpronounceable letter strings. Significant activation for semantic decision in the left inferior frontal gyrus (Brodmann areas 44 and 45) was found in the control group. Corresponding activation in the autism group was more limited, with smaller clusters in left inferior frontal areas 45 and 47. Autistic participants, however, showed significantly greater activation compared to controls in extrastriate visual cortex bilaterally (areas 18 and 19), which correlated with greater number of errors on the semantic task. Our findings suggest an important role of perceptual components (possibly visual imagery) during semantic decision, consistent with previous evidence of atypical lexicosemantic performance in autism. In the context of similar findings from younger typically developing children, our results suggest an immature pattern associated with inefficient processing, presumably due to atypical experiential embedding of word acquisition in autism. (c) 2007 Elsevier Ltd. All rights reserved.