Wang A Ting, Lee Susan S, Sigman Marian, Dapretto Mirella
Department of Psychiatry, University of California, Los Angeles, USA.
Arch Gen Psychiatry. 2007 Jun;64(6):698-708. doi: 10.1001/archpsyc.64.6.698.
Understanding a speaker's communicative intent in everyday interactions is likely to draw on cues such as facial expression and tone of voice. Prior research has shown that individuals with autism spectrum disorders (ASD) show reduced activity in brain regions that respond selectively to the face and voice. However, there is also evidence that activity in key regions can be increased if task demands allow for explicit processing of emotion.
To examine the neural circuitry underlying impairments in interpreting communicative intentions in ASD using irony comprehension as a test case, and to determine whether explicit instructions to attend to facial expression and tone of voice will elicit more normative patterns of brain activity.
DESIGN, SETTING, AND PARTICIPANTS: Eighteen boys with ASD (aged 7-17 years, full-scale IQ >70) and 18 typically developing (TD) boys underwent functional magnetic resonance imaging at the Ahmanson-Lovelace Brain Mapping Center, University of California, Los Angeles.
Blood oxygenation level-dependent brain activity during the presentation of short scenarios involving irony. Behavioral performance (accuracy and response time) was also recorded.
Reduced activity in the medial prefrontal cortex and right superior temporal gyrus was observed in children with ASD relative to TD children during the perception of potentially ironic vs control scenarios. Importantly, a significant group x condition interaction in the medial prefrontal cortex showed that activity was modulated by explicit instructions to attend to facial expression and tone of voice only in the ASD group. Finally, medial prefrontal cortex activity was inversely related to symptom severity in children with ASD such that children with greater social impairment showed less activity in this region.
Explicit instructions to attend to facial expression and tone of voice can elicit increased activity in the medial prefrontal cortex, part of a network important for understanding the intentions of others, in children with ASD. These findings suggest a strategy for future intervention research.
在日常互动中理解说话者的交际意图可能会借助面部表情和语调等线索。先前的研究表明，患有自闭症谱系障碍（ASD）的个体在对脸部和声音进行选择性反应的脑区活动减少。然而，也有证据表明，如果任务要求允许对情绪进行明确处理，关键区域的活动可以增加。
以反讽理解作为测试案例，研究自闭症谱系障碍患者在解释交际意图时潜在损伤背后的神经回路，并确定明确指示关注面部表情和语调是否会引发更规范的脑活动模式。
设计、地点和参与者：18名患有自闭症谱系障碍的男孩（年龄7 - 17岁，全量表智商>70）和18名发育正常（TD）的男孩在加利福尼亚大学洛杉矶分校的艾哈迈森 - 洛夫莱斯脑图谱中心接受了功能磁共振成像检查。
在呈现包含反讽的简短场景时，基于血氧水平依赖的脑活动。还记录了行为表现（准确性和反应时间）。
与发育正常的儿童相比，患有自闭症谱系障碍的儿童在感知潜在反讽场景与对照场景时，内侧前额叶皮质和右侧颞上回的活动减少。重要的是，内侧前额叶皮质中显著的组×条件交互作用表明，只有在自闭症谱系障碍组中，明确指示关注面部表情和语调才会调节活动。最后，内侧前额叶皮质活动与自闭症谱系障碍儿童的症状严重程度呈负相关，即社交障碍越严重的儿童该区域的活动越少。
明确指示关注面部表情和语调可以使自闭症谱系障碍儿童内侧前额叶皮质的活动增加，内侧前额叶皮质是理解他人意图的重要网络的一部分。这些发现为未来的干预研究提出了一种策略。
