Larger Extrastriate Population Receptive Fields in Autism Spectrum Disorders
Larger Extrastriate Population Receptive Fields in Autism Spectrum Disorders
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DOI：
10.1523/jneurosci.4416-13.2014
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发表时间：
2014-02-12
影响因子：
5.3
通讯作者：
Rees, Geraint
中科院分区：
文献类型：
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作者：
Schwarzkopf, D. Samuel;Anderson, Elaine J.;Rees, Geraint
先前的行为研究表明，自闭症谱系障碍（ASD）患者的局部视觉处理增强。在这里，我们使用功能性MRI和群体感受野（pRF）分析，以测试人类视觉皮层的反应选择性是否是非典型的高功能ASD的个体相比，神经典型的，人口统计学匹配的控制。对于每个体素，我们将pRF模型拟合到fMRI信号，而参与者在观看穿越视野的闪烁条刺激时测量。在大多数纹外区域，ASD组的中央凹周围pRF大于对照组。我们观察到V1或V3 A无差异。血流动力学反应功能、眼球运动或测量噪声增加的差异不能解释这些结果; ASD患者对视觉刺激表现出更强、更可靠的反应。有趣的是，PRF大小也与自闭症特征的个体差异相关，但与视觉处理的行为测量没有相关性。因此，我们的研究结果表明，ASD的视觉皮层的特点是没有更清晰的空间选择性。相反，我们推测，ASD的视觉皮层功能的特点可能是外纹皮层过度兴奋或差异注意力部署。
Previous behavioral research suggests enhanced local visual processing in individuals with autism spectrum disorders (ASDs). Here we used functional MRI and population receptive field (pRF) analysis to test whether the response selectivity of human visual cortex is atypical in individuals with high-functioning ASDs compared with neurotypical, demographically matched controls. For each voxel, we fitted a pRF model to fMRI signals measured while participants viewed flickering bar stimuli traversing the visual field. In most extra-striate regions, perifoveal pRFs were larger in the ASD group than in controls. We observed no differences in V1 or V3A. Differences in the hemodynamic response function, eye movements, or increased measurement noise could not account for these results; individuals with ASDs showed stronger, more reliable responses to visual stimulation. Interestingly, pRF sizes also correlated with individual differences in autistic traits but there were no correlations with behavioral measures of visual processing. Our findings thus suggest that visual cortex in ASDs is not characterized by sharper spatial selectivity. Instead, we speculate that visual cortical function in ASDs may be characterized by extrastriate cortical hyperexcitability or differential attentional deployment.