Roxelyn and Richard Pepper Department of Communication Sciences & Disorders, Northwestern University, Evanston, Illinois, United States of America.
PLoS One. 2012;7(4):e34243. doi: 10.1371/journal.pone.0034243. Epub 2012 Apr 17.
The ASPM and MCPH1 genes have been implicated in the adaptive evolution of the human brain [Mekel-Bobrov N. et al., 2005. Ongoing adaptive evolution of ASPM, a brain size determinant in homo sapiens. Science 309; Evans P.D. et al., 2005. Microcephalin, a gene regulating brain size, continues to evolve adaptively in humans. Science 309]. Curiously, experimental attempts have failed to connect the implicated SNPs in these genes with higher-level brain functions. These results stand in contrast with a population-level study linking the population frequency of their alleles with the tendency to use lexical tones in a language [Dediu D., Ladd D.R., 2007. Linguistic tone is related to the population frequency of the adaptive haplogroups of two brain size genes, ASPM and microcephalin. Proc. Natl. Acad. Sci. U.S.A. 104]. In the present study, we found a significant correlation between the load of the derived alleles of ASPM and tone perception in a group of European Americans who did not speak a tone language. Moreover, preliminary results showed a significant correlation between ASPM load and hemodynamic responses to lexical tones in the auditory cortex, and such correlation remained after phonemic awareness, auditory working memory, and non-verbal IQ were controlled. As in previous studies, no significant correlation between ASPM and cognitive measures were found. MCPH1 did not correlate with any measures. These results suggest that the association between the recently derived allele of ASPM is likely to be specific and is tied to higher level brain functions in the temporal cortex related to human communication.
ASPM 和 MCPH1 基因与人类大脑的适应性进化有关[Mekel-Bobrov N.等人，2005。ASPM 是人类大脑大小的决定因素，持续进行适应性进化。科学 309；Evans P.D.等人，2005。调节大脑大小的微脑症基因继续在人类中进行适应性进化。科学 309]。奇怪的是，实验尝试未能将这些基因中涉及的 SNP 与更高层次的大脑功能联系起来。这些结果与一项群体水平的研究形成对比，该研究将这些等位基因的群体频率与语言中使用词汇声调的倾向联系起来[Dediu D.，Ladd D.R.，2007。语言的声调与两个大脑大小基因的适应性单倍群的人口频率有关，ASPM 和微脑症。美国国家科学院院刊 104]。在本研究中，我们发现一组未说声调语言的欧洲裔美国人中，ASPM 衍生等位基因的负荷与声调感知之间存在显著相关性。此外，初步结果显示，ASPM 负荷与听觉皮层对词汇声调的血流动力学反应之间存在显著相关性，并且在控制了语音意识、听觉工作记忆和非言语智商后，这种相关性仍然存在。与之前的研究一样，ASPM 与认知测量之间没有显著相关性。MCPH1 与任何测量都没有相关性。这些结果表明，ASPM 最近衍生的等位基因之间的关联可能是特异性的，与与人类交流相关的颞叶皮层的更高层次的大脑功能有关。
