Takesaki Natsumi, Kikuchi Mitsuru, Yoshimura Yuko, Hiraishi Hirotoshi, Hasegawa Chiaki, Kaneda Reizo, Nakatani Hideo, Takahashi Tetsuya, Mottron Laurent, Minabe Yoshio
Department of Psychiatry & Behavioral Science, Graduate School of Medical Science, Kanazawa University, Kanazawa, 920-8640, Japan.
Research Center for Child Mental Development, Kanazawa University, Kanazawa, 920-8640, Japan.
PLoS One. 2016 Sep 15;11(9):e0163133. doi: 10.1371/journal.pone.0163133. eCollection 2016.
Some individuals with autism spectrum (AS) perform better on visual reasoning tasks than would be predicted by their general cognitive performance. In individuals with AS, mechanisms in the brain's visual area that underlie visual processing play a more prominent role in visual reasoning tasks than they do in normal individuals. In addition, increased connectivity with the visual area is thought to be one of the neural bases of autistic visual cognitive abilities. However, the contribution of such brain connectivity to visual cognitive abilities is not well understood, particularly in children. In this study, we investigated how functional connectivity between the visual areas and higher-order regions, which is reflected by alpha, beta and gamma band oscillations, contributes to the performance of visual reasoning tasks in typically developing (TD) (n = 18) children and AS children (n = 18). Brain activity was measured using a custom child-sized magneto-encephalograph. Imaginary coherence analysis was used as a proxy to estimate the functional connectivity between the occipital and other areas of the brain. Stronger connectivity from the occipital area, as evidenced by higher imaginary coherence in the gamma band, was associated with higher performance in the AS children only. We observed no significant correlation between the alpha or beta bands imaginary coherence and performance in the both groups. Alpha and beta bands reflect top-down pathways, while gamma band oscillations reflect a bottom-up influence. Therefore, our results suggest that visual reasoning in AS children is at least partially based on an enhanced reliance on visual perception and increased bottom-up connectivity from the visual areas.
一些患有自闭症谱系障碍（AS）的个体在视觉推理任务上的表现优于其一般认知能力所预测的水平。在患有AS的个体中，大脑视觉区域中负责视觉处理的机制在视觉推理任务中所起的作用比在正常个体中更为突出。此外，与视觉区域增强的连通性被认为是自闭症视觉认知能力的神经基础之一。然而，这种大脑连通性对视觉认知能力的贡献尚未得到充分理解，尤其是在儿童中。在本研究中，我们调查了由α、β和γ波段振荡反映的视觉区域与高阶区域之间的功能连通性如何影响典型发育（TD）儿童（n = 18）和AS儿童（n = 18）在视觉推理任务中的表现。使用定制的儿童尺寸脑磁图仪测量大脑活动。采用想象相干分析作为估计枕叶与大脑其他区域之间功能连通性的替代方法。仅在AS儿童中，γ波段更高的想象相干所证明的来自枕叶区域更强的连通性与更高的表现相关。我们在两组中均未观察到α或β波段想象相干与表现之间的显著相关性。α和β波段反映自上而下的通路，而γ波段振荡反映自下而上的影响。因此，我们的结果表明，AS儿童的视觉推理至少部分基于对视觉感知的增强依赖以及来自视觉区域增加的自下而上的连通性。
