Gomot Marie, Belmonte Matthew K, Bullmore Edward T, Bernard Frédéric A, Baron-Cohen Simon
INSERM U930, Centre de Pédopsychiatrie, CHU Bretonneau, Tours Cedex 9, France.
Brain. 2008 Sep;131(Pt 9):2479-88. doi: 10.1093/brain/awn172. Epub 2008 Jul 31.
Although communication and social difficulties in autism have received a great deal of research attention, the other key diagnostic feature, extreme repetitive behaviour and unusual narrow interests, has been addressed less often. Also known as 'resistance to change' this may be related to atypical processing of infrequent, novel stimuli. This can be tested at sensory and neural levels. Our aims were to (i) examine auditory novelty detection and its neural basis in children with autism spectrum conditions (ASC) and (ii) test for brain activation patterns that correlate quantitatively with number of autistic traits as a test of the dimensional nature of ASC. The present study employed event-related fMRI during a novel auditory detection paradigm. Participants were twelve 10- to 15-year-old children with ASC and a group of 12 age-, IQ- and sex-matched typical controls. The ASC group responded faster to novel target stimuli. Group differences in brain activity mainly involved the right prefrontal-premotor and the left inferior parietal regions, which were more activated in the ASC group than in controls. In both groups, activation of prefrontal regions during target detection was positively correlated with Autism Spectrum Quotient scores measuring the number of autistic traits. These findings suggest that target detection in autism is associated not only with superior behavioural performance (shorter reaction time) but also with activation of a more widespread network of brain regions. This pattern also shows quantitative variation with number of autistic traits, in a continuum that extends to the normal population. This finding may shed light on the neurophysiological process underlying narrow interests and what clinically is called 'need for sameness'.
尽管自闭症中的沟通和社交困难已受到大量研究关注，但另一个关键诊断特征，即极端重复行为和异常狭窄的兴趣，却较少得到探讨。这也被称为“抗拒改变”，可能与对罕见、新颖刺激的非典型处理有关。这可以在感官和神经层面进行测试。我们的目标是：（i）研究自闭症谱系障碍（ASC）儿童的听觉新颖性检测及其神经基础；（ii）测试与自闭症特征数量定量相关的脑激活模式，以此作为对ASC维度性质的一种检验。本研究在一种新颖的听觉检测范式中采用了事件相关功能磁共振成像技术。参与者为12名10至15岁的ASC儿童以及一组年龄、智商和性别匹配的12名典型对照组儿童。ASC组对新颖目标刺激的反应更快。脑活动的组间差异主要涉及右前额叶 - 运动前区和左顶下叶区域，ASC组在这些区域的激活程度高于对照组。在两组中，目标检测期间前额叶区域的激活与测量自闭症特征数量的自闭症谱系商数得分呈正相关。这些发现表明，自闭症中的目标检测不仅与优越的行为表现（更短的反应时间）相关，还与更广泛的脑区网络激活有关。这种模式也随着自闭症特征数量呈现出定量变化，在一个延伸至正常人群的连续体中。这一发现可能有助于揭示狭窄兴趣以及临床上所谓的“对一致性的需求”背后的神经生理过程。
