Is He Being Bad? Social and Language Brain Networks during Social Judgment in Children with Autism

Individuals with autism often violate social rules and have lower accuracy in identifying and explaining inappropriate social behavior. Twelve children with autism (AD) and thirteen children with typical development (TD) participated in this fMRI study of the neurofunctional basis of social judgment. Participants indicated in which of two pictures a boy was being bad (Social condition) or which of two pictures was outdoors (Physical condition). In the within-group Social–Physical comparison, TD children used components of mentalizing and language networks [bilateral inferior frontal gyrus (IFG), bilateral medial prefrontal cortex (mPFC), and bilateral posterior superior temporal sulcus (pSTS)], whereas AD children used a network that was primarily right IFG and bilateral pSTS, suggesting reduced use of social and language networks during this social judgment task. A direct group comparison on the Social–Physical contrast showed that the TD group had greater mPFC, bilateral IFG, and left superior temporal pole activity than the AD group. No regions were more active in the AD group than in the group with TD in this comparison. Both groups successfully performed the task, which required minimal language. The groups also performed similarly on eyetracking measures, indicating that the activation results probably reflect the use of a more basic strategy by the autism group rather than performance disparities. Even though language was unnecessary, the children with TD recruited language areas during the social task, suggesting automatic encoding of their knowledge into language; however, this was not the case for the children with autism. These findings support behavioral research indicating that, whereas children with autism may recognize socially inappropriate behavior, they have difficulty using spoken language to explain why it is inappropriate. The fMRI results indicate that AD children may not automatically use language to encode their social understanding, making expression and generalization of this knowledge more difficult.自闭症（autism）患者常违背社交规则，且在识别与解释不当社交行为时准确率偏低。本项探究社交判断神经功能基础的功能磁共振成像（functional magnetic resonance imaging, fMRI）研究，共招募12名自闭症儿童（AD）与13名典型发育儿童（TD）作为被试。被试需在两张图片中选择“男孩行为不当”的场景（社交任务），或选择“户外场景”的图片（物理任务）。在组内社交-物理任务对比中，典型发育儿童激活了心理化与语言网络的相关脑区，包括双侧额下回（inferior frontal gyrus, IFG）、双侧内侧前额叶皮层（medial prefrontal cortex, mPFC）以及双侧后颞上沟（posterior superior temporal sulcus, pSTS）；而自闭症儿童则主要激活了由右侧额下回与双侧后颞上沟构成的网络，这表明自闭症儿童在完成该社交判断任务时，对社交与语言网络的调用程度显著降低。针对社交-物理任务的脑区激活差异进行直接组间比较后发现，典型发育组的内侧前额叶皮层、双侧额下回以及左侧颞极上区的激活程度显著高于自闭症组；而自闭症组未出现任何激活程度高于典型发育组的脑区。两组被试均顺利完成了任务，且任务对语言能力的要求极低。两组在眼动追踪指标上的表现也无显著差异，这提示本次fMRI的激活结果更可能反映出自闭症组采用了更为基础的认知策略，而非两组间存在行为表现差异。尽管任务无需依赖语言能力，但典型发育儿童在社交任务中仍激活了语言相关脑区，这表明他们会自动将社交认知编码为语言形式；而自闭症儿童则未表现出这一现象。上述研究结果支持了相关行为学研究的结论：尽管自闭症儿童或许能够识别不当社交行为，但他们难以通过口头语言解释该行为为何不当。本次fMRI结果进一步表明，自闭症儿童可能不会自动将社交理解编码为语言形式，这使得这类知识的表达与泛化更为困难。