A new biochemical atlas finds consistency, complexity, and precision in the human brain.

The Allen Institute for Brain Science has just published its Human Brain Atlas in Nature (Hawlyrycz et al., “An anatomically comprehensive atlas of the adult human brain transcriptome, Nature 489, 20 Sept. 2012, pp. 391–399, doi:10.1038/nature11405). Science Daily printed this summary of what they did:

The results of this study are based on extensive analysis of the Allen Human Brain Atlas, specifically the detailed all-genes, all-structures survey of genes at work throughout the human brain. This dataset profiles 400 to 500 distinct brain areas per hemisphere using microarray technology and comprises more than 100 million gene expression measurements covering three individual human brains to date. Among other findings, these data show that 84% of all genes are expressed somewhere in the human brain and in patterns that are substantially similar from one brain to the next.

Even so, they “only scratched the surface” of the contents of their data set. The findings should lay to rest two common misconceptions in popular mythology, (1) that humans only use 10% of their brains, and (2) that right-brained people are different than left-brained. Science Daily said,

The right and left hemispheres show no significant differences in molecular architecture. This suggests that functions such as language, which are generally handled by one side of the brain, likely result from more subtle differences between hemispheres or structural variation in size or circuitry, but not from a deeper molecular basis.

In addition, they found high homogeneity in the gray matter, suggesting that “same basic functional elements are used throughout the cortex”.

The statement that brain patterns are substantially similar between brains may inform philosophical questions about how well we can communicate with one another. The three examined were “high-quality, clinically unremarkable brains,” they said – i.e., not geniuses, but ordinary folks. (The sample size is still too small to make generalizations about differences due to sex and ethnicity.)….

Continue Reading on crev.info