Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital of the RWTH Aachen, Aachen, Germany.
Neuropsychologia. 2012 Dec;50(14):3440-9. doi: 10.1016/j.neuropsychologia.2012.09.029. Epub 2012 Sep 24.
Individuals with autism spectrum disorder (ASD) often fail to attach context to their memories and are specifically impaired in processing social aspects of contextual information. The aim of the present study was to investigate the modulatory influence of social vs. non-social context on neural mechanisms during encoding in ASD. Using event-related fMRI, 13 boys with ASD and 13 typically developing boys comparable for age and IQ were investigated during encoding of neutral objects presented either with a social (faces) or a non-social (houses) context. A memory paradigm was then applied to identify brain activation patterns associated with encoding of subsequently recollected versus non-recollected objects. On the behavioural level, no significant between-group differences emerged. In particular, no differential effects of context on memory performance were observed. Neurally, however, context-specific group differences were observed in several brain regions. During encoding of subsequently recollected objects presented with a face, ASD subjects (compared to controls) showed reduced neural activation in the bilateral inferior frontal gyrus, bilateral middle frontal gyrus and right inferior parietal lobule. Neural activation in the right inferior frontal gyrus was positively correlated with memory performance in controls, but negatively in ASD individuals. During encoding of subsequently non-recollected objects presented in the non-social context, ASD subjects showed increased activation in the dorsal MPFC. Our findings suggest that in ASD subjects, fronto-parietal brain regions subserving memory formation and the association of contextual information are activated atypically when a social context is presented at encoding. The data add to findings from related research fields indicating that in ASD, socioemotional impairment extends into domains beyond social cognition. Increased activation in the dorsal MPFC in ASD individuals might reflect supervisory cognitive processes related to the suppression of a distracting non-social context.
自闭症谱系障碍（ASD）个体通常无法将背景信息与记忆联系起来，并且在处理背景信息的社会方面存在明显的缺陷。本研究旨在探讨社会与非社会背景对 ASD 个体在编码过程中的神经机制的调节影响。使用事件相关 fMRI，对 13 名 ASD 男孩和 13 名年龄和智商匹配的正常发育男孩进行了研究，在编码中性物体时，这些物体分别呈现社会（面孔）或非社会（房屋）背景。然后应用记忆范式来识别与随后回忆和非回忆物体编码相关的大脑激活模式。在行为水平上，两组之间没有显著差异。特别是，没有观察到背景对记忆表现的差异影响。然而，从神经角度来看，在几个大脑区域观察到了特定于上下文的组间差异。在随后用面孔呈现的可回忆物体的编码过程中，与对照组相比，ASD 受试者（与对照组相比）双侧额下回、双侧额中回和右侧顶下小叶的神经激活减少。在对照组中，右侧额下回的神经激活与记忆表现呈正相关，而在 ASD 个体中则呈负相关。在随后非回忆物体的编码过程中，在非社会背景下呈现，与对照组相比，ASD 受试者背侧 MPFC 的激活增加。我们的研究结果表明，在 ASD 受试者中，当在编码时呈现社会背景时，参与记忆形成和上下文信息关联的额顶叶脑区的激活是异常的。这些数据增加了来自相关研究领域的发现，表明在 ASD 中，社交情感障碍不仅局限于社会认知领域。ASD 个体中背侧 MPFC 的激活增加可能反映了与抑制分散的非社会背景相关的监督认知过程。
