Department of Cognitive Neuroscience, Universiteit Maastricht, The Netherlands.
Biol Psychiatry. 2010 Dec 15;68(12):1107-13. doi: 10.1016/j.biopsych.2010.06.024. Epub 2010 Aug 21.
A detailed visual processing style has been noted in autism spectrum disorder (ASD); this contributes to problems in face processing and has been directly related to abnormal processing of spatial frequencies (SFs). Little is known about the early development of face processing in ASD and the relation with abnormal SF processing. We investigated whether young ASD children show abnormalities in low spatial frequency (LSF, global) and high spatial frequency (HSF, detailed) processing and explored whether these are crucially involved in the early development of face processing.
Three- to 4-year-old children with ASD (n = 22) were compared with developmentally delayed children without ASD (n = 17). Spatial frequency processing was studied by recording visual evoked potentials from visual brain areas while children passively viewed gratings (HSF/LSF). In addition, children watched face stimuli with different expressions, filtered to include only HSF or LSF.
Enhanced activity in visual brain areas was found in response to HSF versus LSF information in children with ASD, in contrast to control subjects. Furthermore, facial-expression processing was also primarily driven by detail in ASD.
Enhanced visual processing of detailed (HSF) information is present early in ASD and occurs for neutral (gratings), as well as for socially relevant stimuli (facial expressions). These data indicate that there is a general abnormality in visual SF processing in early ASD and are in agreement with suggestions that a fast LSF subcortical face processing route might be affected in ASD. This could suggest that abnormal visual processing is causative in the development of social problems in ASD.
自闭症谱系障碍（ASD）患者存在详细的视觉加工模式；这导致了他们在面孔加工方面的问题，并且与空间频率（SF）的异常处理直接相关。关于 ASD 中早期的面孔加工发展以及与异常 SF 加工的关系，我们知之甚少。我们调查了 ASD 儿童是否在低空间频率（LSF，整体）和高空间频率（HSF，细节）加工中表现出异常，并且探索了这些异常是否与面孔加工的早期发展密切相关。
我们将 3 至 4 岁的 ASD 儿童（n = 22）与无 ASD 的发育延迟儿童（n = 17）进行了比较。通过记录儿童被动观看光栅（HSF/LSF）时视觉脑区的视觉诱发电位来研究 SF 处理。此外，儿童观看了不同表情的面孔刺激，这些刺激仅包含 HSF 或 LSF。
与对照组相比，ASD 儿童的视觉脑区对 HSF 与 LSF 信息的反应表现出增强的活动。此外，在 ASD 中，表情处理也主要由细节驱动。
ASD 早期存在对详细（HSF）信息的增强视觉处理，并且这种处理不仅针对中性（光栅）刺激，也针对社会相关刺激（面部表情）。这些数据表明，ASD 中存在 SF 处理的一般异常，并且与以下观点一致，即 ASD 中可能存在一个快速的 LSF 皮质下面孔处理途径受到影响。这可能表明异常的视觉处理是 ASD 中社会问题发展的原因。
