Child Neuropsychology Section, Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of the RWTH Aachen, D-52074 Aachen, Germany.
Neuropsychologia. 2010 May;48(6):1644-51. doi: 10.1016/j.neuropsychologia.2010.02.007. Epub 2010 Feb 12.
A deficit in global motion processing caused by a specific dysfunction of the visual dorsal pathway has been suggested to underlie perceptual abnormalities in subjects with autism spectrum disorders (ASD). However, the neural mechanisms associated with abnormal motion processing in ASD remain poorly understood. We investigated brain responses related to the detection of coherent and random motion in 15 male subjects with ASD and 15 age- and IQ-matched healthy controls (aged 13-19 years) using event-related functional magnetic resonance imaging (fMRI). Behaviorally, no significant group differences were observed between subjects with ASD and controls. Neurally, subjects with ASD showed increased brain activation in the left primary visual cortex across all conditions compared with controls. A significant interaction effect between group and condition was observed in the right superior parietal cortex resulting from increased neural activity in the coherent compared with the random motion conditions only in the control group. In addition, neural activity in area V5 was not differentially modulated by specific motion conditions in subjects with ASD. Functional connectivity analyses revealed positive correlations between the primary visual cortex and area V5 within both hemispheres, but no significant between-group differences in functional connectivity patterns along the dorsal stream. The data suggest that motion processing in ASD results in deviant activations in both the lower and higher processing stages of the dorsal pathway. This might reflect differences in the perception of visual stimuli in ASD, which possibly result in impaired integration of motion signals.
一种由视觉背侧通路特定功能障碍引起的全局运动处理缺陷，被认为是孤独症谱系障碍（ASD）患者感知异常的基础。然而，与 ASD 中异常运动处理相关的神经机制仍知之甚少。我们使用事件相关功能磁共振成像（fMRI）研究了 15 名男性 ASD 患者和 15 名年龄和智商匹配的健康对照者（年龄 13-19 岁）在检测连贯和随机运动时与大脑反应相关的情况。行为上，ASD 患者和对照组之间没有观察到显著的组间差异。神经上，与对照组相比，ASD 患者在所有条件下左侧初级视觉皮层的大脑激活增加。在右顶上小叶观察到组间和条件间的显著交互效应，这是由于对照组在连贯运动条件下比随机运动条件下的神经活动增加所致。此外，ASD 患者的 V5 区的神经活动没有被特定的运动条件差异调节。功能连接分析显示，在两个半球内初级视觉皮层和 V5 区之间存在正相关，但沿背侧通路的功能连接模式在组间没有显著差异。数据表明，ASD 中的运动处理导致背侧通路的较低和较高处理阶段出现异常激活。这可能反映了 ASD 中视觉刺激感知的差异，这可能导致运动信号的整合受损。
