Faculty of Psychology and Educational Science, Ghent University, Henri Dunantlaan 2, 9000 Ghent, Belgium.
Faculty of Psychology and Educational Science, Ghent University, Henri Dunantlaan 2, 9000 Ghent, Belgium.
Neuroimage Clin. 2018 Feb 17;18:475-484. doi: 10.1016/j.nicl.2018.02.016. eCollection 2018.
The socio-communicative difficulties of individuals with autism spectrum disorder (ASD) are hypothesized to be caused by a specific deficit in the ability to represent one's own and others' mental states, referred to as Theory of Mind or mentalizing. However, many individuals with ASD show successful performance on explicit measures of mentalizing, and for this reason, the deficit is thought to be better captured by measures of spontaneous mentalizing. While there is initial behavioral support for this hypothesis, spontaneous mentalizing in ASD has not yet been studied at the neural level. Recent findings indicate involvement of the right temporoparietal junction (rTPJ) in both explicit and spontaneous mentalizing (Bardi et al., 2016). In the current study, we investigated brain activation during explicit and spontaneous mentalizing in adults with ASD by means of fMRI. Based on our hypothesis of a core mentalizing deficit in ASD, decreased rTPJ activity was expected for both forms of mentalizing. A group of 24 adults with ASD and 21 neurotypical controls carried out a spontaneous and an explicit version of the same mentalizing task. They watched videos in which both they themselves and another agent formed a belief about the location of an object (belief formation phase). Only in the explicit task version participants were instructed to report the agent's belief on some trials. At the behavioral level, no group differences were revealed in either of the task versions. A planned region-of-interest analysis of the rTPJ showed that this region was more active for false- than for true-belief formation, independent of task version, especially when the agent's belief had a positive content (when the agent was expecting the object). This effect of belief was absent in adults with ASD. A whole-brain analysis revealed reduced activation in the anterior middle temporal pole in ASD for false - versus true-belief trials, independent of task version. Our findings suggest neural differences between adults with ASD and neurotypical controls both during spontaneous and explicit mentalizing, and indicate the rTPJ to be crucially involved in ASD. Moreover, the possible role of the anterior middle temporal pole in disturbed mentalizing in ASD deserves further attention. The finding that these neural differences do not necessarily lead to differential performance warrants further research.
自闭症谱系障碍（ASD）个体的社交沟通困难被假设是由于代表自己和他人心理状态的能力出现特定缺陷所致，这种能力通常被称为心理理论或心理化。然而，许多 ASD 个体在心理化的明确测量中表现出成功的表现，因此，这种缺陷被认为可以通过自发心理化的测量更好地捕捉到。尽管这一假设在行为上得到了初步支持，但 ASD 中的自发心理化尚未在神经水平上进行研究。最近的研究结果表明，右颞顶联合区（rTPJ）在明确的和自发的心理化中都有涉及（Bardi 等人，2016）。在目前的研究中，我们通过 fMRI 研究了 ASD 成年人在明确的和自发的心理化过程中的大脑激活。根据我们在 ASD 中存在核心心理化缺陷的假设，我们预计这两种形式的心理化都会导致 rTPJ 活动减少。一组 24 名 ASD 成年人和 21 名神经典型对照组进行了相同的心理化任务的自发和明确版本。他们观看了视频，在视频中，他们自己和另一个代理形成了对物体位置的信念（信念形成阶段）。只有在明确的任务版本中，参与者才被指示在某些试验中报告代理的信念。在行为层面上，在任何一种任务版本中，都没有发现组间差异。rTPJ 的计划区域兴趣分析表明，该区域在错误信念形成时比真实信念形成时更活跃，与任务版本无关，尤其是当代理的信念具有积极内容时（当代理期望物体时）。这种信念效应在 ASD 成年人中不存在。全脑分析显示，在 ASD 中，与真实信念试验相比，在前中部颞极点，在虚假-与真实信念试验中，活动减少，与任务版本无关。我们的研究结果表明，ASD 成年人与神经典型对照组在自发和明确的心理化过程中存在神经差异，并表明 rTPJ 在 ASD 中起着至关重要的作用。此外，中颞极前部在 ASD 中干扰心理化的可能作用值得进一步关注。这些神经差异不一定导致不同表现的发现需要进一步研究。
