Woods Keri J, Jacobson Sandra W, Molteno Christopher D, Jacobson Joseph L, Meintjes Ernesta M
Division of Biomedical Engineering, Department of Human Biology, University of Cape Town, Cape Town, South Africa.
Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
Front Hum Neurosci. 2018 Jan 8;11:627. doi: 10.3389/fnhum.2017.00627. eCollection 2017.
Number processing is a cognitive domain particularly sensitive to prenatal alcohol exposure, which relies on intact parietal functioning. Alcohol-related alterations in brain activation have been found in the parietal lobe during symbolic number processing. However, the effects of prenatal alcohol exposure on the neural correlates of non-symbolic number comparison and the numerical distance effect have not been investigated. Using functional magnetic resonance imaging (fMRI), we examined differences in brain activation associated with prenatal alcohol exposure in five parietal regions involved in number processing during a non-symbolic number comparison task with varying degrees of difficulty. fMRI results are presented for 27 Cape Colored children (6 fetal alcohol syndome (FAS)/partial FAS, 5 heavily exposed (HE) non-sydromal, 16 controls; mean age ± SD = 11.7 ± 1.1 years). Fetal alcohol exposure was assessed by interviewing mothers using a timeline follow-back approach. Separate subject analyses were performed in each of five regions of interest, bilateral horizontal intraparietal sulci (IPS), bilateral posterior superior parietal lobules (PSPL), and left angular gyrus (left AG), using the general linear model with predictors for number comparison and difficulty level. Mean percent signal change for each predictor was extracted for each subject for each region to examine group differences and associations with continuous measures of alcohol exposure. Although groups did not differ in performance, controls activated the right PSPL more during non-symbolic number comparison than exposed children, but this was not significant after controlling for maternal smoking, and the right IPS more than children with fetal alcohol syndrome (FAS) or partial FAS. More heavily exposed children recruited the left AG to a greater extent as task difficulty increased, possibly to compensate, in part, for impairments in function in the PSPL and IPS. Notably, in non-syndromal heavily exposed children activation was impaired in the right PSPL, but spared in the right IPS. These results extend previous findings of poor right IPS recruitment during symbolic number processing in FAS/PFAS, indicating that mental representation of relative quantity is affected by prenatal alcohol exposure for both symbolic and non-symbolic representations of quantity.
数字处理是一个对产前酒精暴露特别敏感的认知领域，它依赖于完整的顶叶功能。在符号数字处理过程中，已发现顶叶存在与酒精相关的大脑激活改变。然而，产前酒精暴露对非符号数字比较的神经关联及数字距离效应的影响尚未得到研究。我们使用功能磁共振成像（fMRI），在一项具有不同难度程度的非符号数字比较任务中，检查了参与数字处理的五个顶叶区域中与产前酒精暴露相关的大脑激活差异。呈现了27名开普有色人种儿童（6名胎儿酒精综合征（FAS）/部分FAS、5名重度暴露（HE）非综合征患儿、16名对照组儿童；平均年龄±标准差 = 11.7 ± 1.1岁）的fMRI结果。通过使用时间线追溯法访谈母亲来评估产前酒精暴露情况。在五个感兴趣区域，即双侧水平顶内沟（IPS）、双侧后上顶叶小叶（PSPL）和左侧角回（左侧AG），分别进行单独的受试者分析，使用带有数字比较和难度水平预测因子的一般线性模型。为每个受试者的每个区域提取每个预测因子的平均信号变化百分比，以检查组间差异以及与酒精暴露连续测量值的关联。尽管各组在表现上没有差异，但在非符号数字比较过程中，对照组比暴露儿童更多地激活了右侧PSPL，但在控制母亲吸烟因素后，这一差异并不显著，且对照组激活右侧IPS的程度比患有胎儿酒精综合征（FAS）或部分FAS的儿童更高。随着任务难度增加，暴露程度更高的儿童在更大程度上募集左侧AG，这可能部分是为了补偿PSPL和IPS功能的损伤。值得注意的是，在非综合征重度暴露儿童中，右侧PSPL的激活受损，但右侧IPS未受影响。这些结果扩展了先前关于FAS/PFAS在符号数字处理过程中右侧IPS募集不良的研究发现，表明数量的相对心理表征在数量的符号和非符号表征方面均受到产前酒精暴露的影响。
