Department of Psychiatry, Trinity Centre for Health Sciences, St. James's Hospital, Dublin, Ireland.
Autism Res. 2012 Oct;5(5):314-30. doi: 10.1002/aur.1245. Epub 2012 Aug 4.
Atypical visuospatial processing is commonly described in autism spectrum disorders (ASDs); however the specific neurobiological underpinnings of this phenomenon are poorly understood. Given the extensive evidence suggesting ASDs are characterized by abnormal neural connectivity, this study aimed to investigate network connectivity during visuospatial processing in ASD. Twenty-two males with ASD without intellectual disability and 22 individually matched controls performed a mental rotation task during functional magnetic resonance imaging (MRI) in which two rotated stimuli were judged to be same ("Same Trials") or mirror-imaged ("Mirror Trials"). Behavioral results revealed a relative advantage of mental rotation in the ASD group-controls were slower responding to the more difficult Mirror Trials than Same Trials whereas the ASD group completed Mirror Trials and Same-trials at similar speeds. In the ASD group, brain activity was reduced in frontal, temporal, occipital, striatal, and cerebellar regions and, consistent with previous literature, functional connectivity between a number of brain regions was reduced. However, some connections appeared to be conserved and were recruited in a qualitatively different way by the two groups. As task difficulty increased (on Mirror Trials), controls tended to increase connections between certain brain regions, whereas the ASD group appeared to suppress connections between these regions. There was an interesting exception to this pattern in the visual cortex, a finding that may suggest an advantage in early visual perceptual processing in ASD. Overall, this study has identified a relative advantage in mental rotation in ASD that is associated with aberrant neural connectivity and that may stem from enhanced visual perceptual processing.
非典型的视空间加工在自闭症谱系障碍（ASD）中经常被描述；然而，这种现象的具体神经生物学基础还了解甚少。鉴于大量证据表明 ASD 的特征是异常的神经连接，本研究旨在调查 ASD 患者在进行视空间加工时的网络连接。22 名男性 ASD 患者（无智力障碍）和 22 名个体匹配的对照组在功能磁共振成像（fMRI）中执行心理旋转任务，在该任务中，两个旋转的刺激被判断为相同（“相同试验”）或镜像（“镜像试验”）。行为结果显示，ASD 组在心理旋转方面具有相对优势——对照组对更困难的镜像试验的反应速度较慢，而 ASD 组完成镜像试验和相同试验的速度相似。在 ASD 组中，大脑活动在前额、颞叶、枕叶、纹状体和小脑区域减少，与之前的文献一致，许多大脑区域之间的功能连接减少。然而，一些连接似乎被保留下来，两组以不同的方式招募。随着任务难度的增加（在镜像试验上），对照组倾向于增加某些大脑区域之间的连接，而 ASD 组似乎抑制了这些区域之间的连接。在视觉皮层中出现了一个有趣的例外，这一发现可能表明 ASD 患者在早期视觉感知处理方面具有优势。总的来说，这项研究确定了 ASD 患者在心理旋转方面的相对优势，这与异常的神经连接有关，可能源于增强的视觉感知处理。
