Department of Psychology, University of Michigan, Ann Arbor, Mich. 48109, USA.
J Psychiatry Neurosci. 2010 Mar;35(2):105-14. doi: 10.1503/jpn.090085.
Autism spectrum disorders (ASD) are associated with severe impairments in social functioning. Because faces provide nonverbal cues that support social interactions, many studies of ASD have examined neural structures that process faces, including the amygdala, ventromedial prefrontal cortex and superior and middle temporal gyri. However, increases or decreases in activation are often contingent on the cognitive task. Specifically, the cognitive domain of attention influences group differences in brain activation. We investigated brain function abnormalities in participants with ASD using a task that monitored attention bias to emotional faces.
Twenty-four participants (12 with ASD, 12 controls) completed a functional magnetic resonance imaging study while performing an attention cuing task with emotional (happy, sad, angry) and neutral faces.
In response to emotional faces, those in the ASD group showed greater right amygdala activation than those in the control group. A preliminary psychophysiological connectivity analysis showed that ASD participants had stronger positive right amygdala and ventromedial prefrontal cortex coupling and weaker positive right amygdala and temporal lobe coupling than controls. There were no group differences in the behavioural measure of attention bias to the emotional faces.
The small sample size may have affected our ability to detect additional group differences.
When attention bias to emotional faces was equivalent between ASD and control groups, ASD was associated with greater amygdala activation. Preliminary analyses showed that ASD participants had stronger connectivity between the amygdala ventromedial prefrontal cortex (a network implicated in emotional modulation) and weaker connectivity between the amygdala and temporal lobe (a pathway involved in the identification of facial expressions, although areas of group differences were generally in a more anterior region of the temporal lobe than what is typically reported for emotional face processing). These alterations in connectivity are consistent with emotion and face processing disturbances in ASD.
自闭症谱系障碍（ASD）与社交功能严重受损有关。由于面部提供了支持社交互动的非言语线索，因此许多 ASD 研究都检查了处理面部的神经结构，包括杏仁核、腹内侧前额叶皮层以及上颞回和中颞回。然而，激活的增加或减少通常取决于认知任务。具体来说，注意力的认知领域会影响大脑激活的组间差异。我们使用监测情绪面孔注意力偏向的任务研究了 ASD 参与者的大脑功能异常。
24 名参与者（12 名 ASD，12 名对照组）在执行带有情绪（快乐、悲伤、愤怒）和中性面孔的注意力提示任务时完成了功能磁共振成像研究。
对于情绪面孔，ASD 组的右杏仁核激活比对照组更强。初步的心理生理连通性分析表明，与对照组相比，ASD 参与者的右杏仁核和腹内侧前额叶皮层的正连通性较强，而右杏仁核和颞叶的正连通性较弱。在对情绪面孔的注意力偏向的行为测量中，两组之间没有差异。
小样本量可能影响了我们检测其他组间差异的能力。
当 ASD 和对照组对情绪面孔的注意力偏向相同时，ASD 与更大的杏仁核激活有关。初步分析表明，ASD 参与者的杏仁核和腹内侧前额叶皮层之间的连通性更强（该网络与情绪调节有关），而杏仁核和颞叶之间的连通性较弱（该通路涉及对面部表情的识别，尽管组间差异的区域通常比通常报道的与情绪面孔处理相关的区域更靠前颞叶）。这些连通性的改变与 ASD 中的情绪和面孔处理障碍一致。
