类比推理的功能性磁共振成像与主成份分析

研究背景：功能性成像已经应用于人脑类比推理研究。但是，由于较小的研究样品，这些研究结果不大一致。方法利用功能性磁共振成像，我们测量了24例健康人的类比推理脑活动。这些功能性磁共振成像数据由统计参数软件（SPMI）处理与主成份分析。结果阳性活动见于双侧大脑半球腹外侧、背外侧前额叶、后顶叶及小脑半球；阴性结果见于双侧大脑半球内前额叶、顶枕额区、扣带回后部及上顶叶。主成份分析表明仅仅只有一个主成份具有大于1．0的特征值，这个成份可以解释93％的总方差。所有的阳性及阴性活动区被包括在这个主成份中。结论人脑的类比推理活动可能是一个由双侧大脑半球内多个阳性及阴性活动区组成的神经网络调节，包括双侧前额叶及后顶叶。

Neural circuits of verbal analogical mapping using functional MRI and principal component analysis

Background Functional imaging studies have investigated the human brain activity during analogy tasks. However, the results from those studies, with relatively small sample sizes, are somewhat inconsistent. Methods Here using blood oxygenation level dependent (BOLD) functional magnetic resonance imaging on 1. ST, we measured brain activation and deactivation during a verbal analogy task in 24 healthy subjects. The functional dada were analyzed using Statistical Parametric Mapping (SPM 2). A principal component analysis (PCA) was performed using BOLD percent signal change across all the activated and deactivated brain regions. Results Significant activations (analogy vs.control task) were found in bilateral ventrolateral prefrontal cortices (PFC), dorsolateral PFC, supplementary motor areas, posterior parietal cortices (PPC), and cerebellums;whereas significant deactivations (control vs. analogy) were noted in bilateral medial PFC, parietoceiptotemporal lobes, posterior cingulate gyri, and superior parietal cortices. PCA of these regions reveled only one component with eigenvalue greater than 1.0 (eigenvalue=12.96) and all of the activated and deactivated brain regions loaded heavily on this component that accounted for approximately 93% of the total variance in activity and deactivity patterns. Conclusion Verbal analogical mapping may be mediated by a dynamic neuronal network containing several activated and deactivated brain regions in both the left and right hemispheres,including bilateral PFC and PPC.