Category: Uncategorized

THE NUMBERS. “With 1468 million neurons, owl monkeys have almost twice as many neurons in the brain as agoutis (which hold 857 million), and about four times more neurons in the cerebral cortex than the agouti (442 million versus 113 million).” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2776484/ View in LinkedIn

SEEKING CORRELATION. “Now that absolute numbers of neurons can be compared across the similar-sized brains of agoutis and owl monkeys, and of capybaras and capuchin monkeys the expected correlation between cognitive ability and numbers of neurons is actually found to hold.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2776484/ View in LinkedIn

ECONOMIC CONSEQUENCES. “The cognitive consequences of this difference, which allows primate brains to enjoy the benefits of a large increase in numbers of neurons without the otherwise associated cost of a much larger increase in overall brain volume, can be glimpsed by returning to the comparison between rodents and primates of similar brain size.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2776484/ View in LinkedIn

CONSIDERING ECONOMY. “By maintaining the average neuronal size (including all arborizations) invariant as brain size changes, primate brains scale in size in a much more space-saving, economical manner compared to the inflationary growth that occurs in rodents, in which larger numbers of neurons are accompanied by larger neurons.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2776484/ View in LinkedIn

RELATED SCALING. “An examination of the cellular composition of the cerebellum of orangutans and one gorilla shows that the sizes of the cerebellum and cerebral cortex predicted for these species from the number of cells in the cerebellum match their actual sizes, which suggests that the brain of these animals indeed is built according to the same scaling rules that apply to humans and other primates.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2776484/ View in LinkedIn

THE FALL OF THE RULE. “The different cellular scaling rules that apply to rodent, primate and insectivore brains show very clearly that brain size cannot be used indiscriminately as a proxy for numbers of neurons in the brain, or even in a brain structure, across orders.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2776484/ View in LinkedIn

ON HUMANS AND PRIMATES. “The finding that the same cellular scaling rules apply to humans and non-anthropoid primate brains alike, irrespective of body size, indicates that the brains of the great apes, which diverged from the hominin lineage before humans, should also conform to the same cellular scaling rules.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2776484/ View in LinkedIn

FRAGMENT FROM NATURE continues from last weekend and concludes this weekend on the theme of the vain quest for human exceptionality due to brain size. This quest was loosely rooted in the astonishing (to us today) assumption that humans are somehow different from the rest of nature, and had allusions to the equally astonishing mind-body debate. But above all, it came from the theme of religious exceptionality of mankind, and the Earth being the center of the universe. View in LinkedIn

DIVERGING CONSEQUENCES. “Since neuronal density does not scale with brain size in primates, but decreases with increasing brain size in rodents, the larger the brain size, the larger is the difference in number of neurons across similar-sized rodent and primate brains.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2776484/ View in LinkedIn

DOWNLOADING TO BRAIN. "Imagine a world wherein you can just download information right into your brain? Just stick a jack into the back of your head, hit the ‘download’ button and away you go! It would be AWESOME, right?" https://lnkd.in/d-GKHuc View in LinkedIn