In fact, puppies acquire 70 % of their
adult brain mass by 6 weeks of age and have 90 % by 12 weeks of age.
Rather, scientists look at
brain mass relative to body mass in order to make any speculation about a creature's cognitive abilities.
It is a lack
of brain mass, because the greatness of leadership is in its ability to transform the society just like the wise Emiratis, Saudis, Qataris etc have done to their countries.
But when the ENIGMA group looked for evidence that schizophrenia patients regain
brain mass as their disease goes on, they didn't find it, though the data do suggest that some areas of the brain begin to thin at a slower rate.
As they report in this week's issue of PNAS,
brain mass accounts for the vast majority (94 %) of the variance in walking time between species.
Two other variables — gestation time and
brain mass at birth — also correlate nicely with age of walking for most animals, but not for humans.
They found 189 reports published before 2010 with comparable corticosterone and
whole brain mass measurements for 119 bird species.
Even if humans could gather this information, our brains wouldn't know what to do with it: the dog olfactory cortex, which processes scent information, takes up 12.5 per cent of their
total brain mass, while ours accounts for less than 1 per cent.
Maintaining body mass,
especially brain mass, is calorically expensive, Lázaro explained; it means that you have to eat a lot of food to power your body, organs and brain.
This follows the pattern reported for
brain mass in anthropoids: species in which brain growth occurs at an earlier age tend to wean late [22].
Research shows that adults who eat the most tuna and other fish rich in DHA have
healthier brain mass as they age, compared to those who eat the least amount of fish.
Strikingly, a model based on
adult brain mass and walking time in the other 23 species almost perfectly predicts when humans begin to walk.
Equally valid metrics might be measured in people - years, (add up the ages), or total national body mass over time, (add up everyone's weight), or
brain mass, (just suppose), or souls sent to heaven, (for highly - informed theocracies).
For each species, the total number of neurons (in millions) in their brains is shown in yellow, the number of neurons (in millions) in their forebrains (pallium) is shown in blue and
their brain mass (in grams) is shown in red.
That makes sense, the researchers say: Humans spend an unusually small portion of their development — and build an unusually small fraction of
their brain mass — in the womb.
They compared the time between conception and walking in 24 species and looked at how well this duration correlated with a range of variables, including gestation time, adult body mass, and adult
brain mass.
Some deviations from this pattern might be expected among lorisids, which have a notably long gestation length, slowly developing brains (low neonatal
brain mass relative to adult brain mass [11]-RRB-, as well as other heterochronic differences compared to most strepsirrhines [47], [48].
We've lost 10 % of
our brain mass since the dawn of agriculture.