期刊
JOURNAL OF COGNITIVE NEUROSCIENCE
卷 12, 期 1, 页码 223-232出版社
M I T PRESS
DOI: 10.1162/089892900561850
关键词
-
资金
- EUNICE KENNEDY SHRIVER NATIONAL INSTITUTE OF CHILD HEALTH & HUMAN DEVELOPMENT [P50HD027802] Funding Source: NIH RePORTER
- EUNICE KENNEDY SHRIVER NATIONAL INSTITUTE OF CHILD HEALTH &HUMAN DEVELOPMENT [P30HD004024] Funding Source: NIH RePORTER
- NATIONAL INSTITUTE OF MENTAL HEALTH [K02MH000419] Funding Source: NIH RePORTER
- NICHD NIH HHS [P50 HD27802, P30 HD04024] Funding Source: Medline
- NIMH NIH HHS [K02 MH00419] Funding Source: Medline
Although it is well known that there is considerable variation among individuals in the size of the human brain, the etiology of less extreme individual differences in brain size is largely unknown. We present here data from the first large twin sample (N = 132 individuals) in which the size of brain structures has been measured. As part of an ongoing project examining the brain correlates of reading disability (RD), whole brain morphometric analyses of structural magnetic response image (MRI) scans were performed on a sample of adolescent twins. Specifically, there were 25 monozygotic (MZ) and 23 dizygotic (DZ) pairs in which at least one member of each pair had RD and 9 MZ and 9 DZ pairs in which neither member had RD. We first factor-analyzed volume data for 13 individual brain structures, comprising all of the neocortex and most of the subcortex. This analysis yielded two factors (cortical and subcortical) that account for 64% of the variance. We next tested whether genetic and environmental influences on brain size variations varied for these two factors or by hemisphere. We computed intraclass correlations within MZ and DZ pairs in each sample for the cortical and subcortical factor scores, for left and right neocortex, and for the total cerebral volume. All five MZ correlations were substantial (r's = .78 to .98) and significant in both samples, as well as being larger than the corresponding DZ correlations, (r's = 0.32 to 0.65) in both samples. The MZ-DZ differences was significant for 3 variables in the RD sample and for one variable in the smaller control sample. These results indicate significant genetic influences on these variables. The magnitude of genetic influence did not vary markedly either for the 2 factors or the 2 hemispheres. There was also a positive correlation between brain size and full-scale IQ, consistent with the results of earlier studies. The total cerebral volume was moderately correlated (r = .42, p < .01, two-tailed) with full-scale IQ in the RD sample; there was a similar trend in the smaller control sample (r = .31, p < .07, two-tailed). Corrections of similar magnitude were found between the subcortical factor and full-scale IQ, whereas the results for the cortical factor (r = .16 and .13) were smaller and not significant. In sum, these results provide evidence for the heritability of individual differences in brain size which do not vary markedly by hemisphere or for neocortex relative to subcortex. Since there are also correlations between brain size and full-scale IQ in this sample, it is possible that genetic influences on brain size partly contribute to individual differences in IQ.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据