Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan.
Psychiatry Res. 2011 Apr 30;192(1):60-6. doi: 10.1016/j.pscychresns.2010.09.008. Epub 2011 Mar 5.
Evidence from neuroimaging and neurobiological studies suggests that abnormalities in cortical-cortical connectivity involving both local and long-distance scales may be related to autism. The present study analyzed the microstructural integrity of the long-range connectivity related to social cognition and language processing with diffusion tractography among adolescents with autism compared with neurotypical adolescents. Tract-specific analyses were used to study the long-range connectivity responsible for integrating social cognition and language processing. Specifically, three pairs of association fibers and three portions of callosal fiber tracts were analyzed. Generalized fractional anisotropy (GFA) values were measured along individual targeted fiber tracts to investigate alterations in microstructure integrity. The asymmetry patterns were also assessed in three pairs of association fibers. In neurotypical participants, we found a consistent leftward asymmetry in three pairs of association fibers. However, adolescents with autism did not demonstrate such asymmetry. Moreover, adolescents with autism had significantly lower mean GFA in three callosal fiber tracts than neurotypical participants. The loss of leftward asymmetry and reduction of interhemispheric connection in adolescents with autism suggest alterations of the long-range connectivity involved in social cognition and language processing. Our results warrant further investigation by combining developmental and neurocognitive data.
神经影像学和神经生物学研究的证据表明，涉及局部和远距离尺度的皮质-皮质连接异常可能与自闭症有关。本研究通过扩散轨迹分析，比较了自闭症青少年和神经典型青少年之间与社会认知和语言处理相关的长程连接的微观结构完整性。使用特定于束的分析来研究负责整合社会认知和语言处理的长程连接。具体来说，分析了三对联合纤维和三个胼胝体纤维束部分。沿着各个目标纤维束测量广义分数各向异性 (GFA) 值，以研究微观结构完整性的变化。还评估了三对联合纤维中的不对称模式。在神经典型参与者中，我们发现三对联合纤维中有一致的左侧不对称性。然而，自闭症青少年没有表现出这种不对称性。此外，自闭症青少年的三个胼胝体纤维束的平均 GFA 明显低于神经典型参与者。自闭症青少年的左侧不对称性丧失和半球间连接减少表明涉及社会认知和语言处理的长程连接发生了变化。我们的结果需要结合发展和神经认知数据进一步研究。
