McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
Neuroimage. 2011 Apr 15;55(4):1443-53. doi: 10.1016/j.neuroimage.2011.01.016. Epub 2011 Jan 15.
Prevailing psychometric theories of intelligence posit that individual differences in cognitive performance are attributable to three main sources of variance: the general factor of intelligence (g), cognitive ability domains, and specific test requirements and idiosyncrasies. Cortical thickness has been previously associated with g. In the present study, we systematically analyzed associations between cortical thickness and cognitive performance with and without adjusting for the effects of g in a representative sample of children and adolescents (N=207, Mean age=11.8; SD=3.5; Range=6 to 18.3 years). Seven cognitive tests were included in a measurement model that identified three first-order factors (representing cognitive ability domains) and one second-order factor representing g. Residuals of the cognitive ability domain scores were computed to represent g-independent variance for the three domains and seven tests. Cognitive domain and individual test scores as well as residualized scores were regressed against cortical thickness, adjusting for age, gender and a proxy measure of brain volume. g and cognitive domain scores were positively correlated with cortical thickness in very similar areas across the brain. Adjusting for the effects of g eliminated associations of domain and test scores with cortical thickness. Within a psychometric framework, cortical thickness correlates of cognitive performance on complex tasks are well captured by g in this demographically representative sample.
目前流行的智力心理学理论认为，认知表现的个体差异归因于三个主要的方差源：智力的一般因素（g）、认知能力领域以及特定的测试要求和特点。皮质厚度先前与 g 有关。在本研究中，我们在一个有代表性的儿童和青少年样本（N=207，平均年龄=11.8；SD=3.5；范围=6 至 18.3 岁）中，系统地分析了皮质厚度与认知表现之间的关联，同时考虑了 g 对认知表现的影响和不考虑 g 对认知表现的影响。在一个测量模型中，包含了七个认知测试，确定了三个一阶因素（代表认知能力领域）和一个代表 g 的二阶因素。计算了认知能力领域得分的残差，以代表三个领域和七个测试的 g 独立方差。在调整年龄、性别和大脑体积的替代测量后，对认知领域和个体测试得分以及残差得分与皮质厚度进行回归分析。g 和认知领域得分与大脑中非常相似的区域的皮质厚度呈正相关。在心理测量学框架内，在这个人口统计学代表性样本中，g 很好地解释了复杂任务的认知表现的皮质厚度相关性。
