ALERT: The Origami Revolution / NOVA – Fabulous video on origami research – Not your grandma’s origami! Watch the section about brain growth and development starting at 19.17 Astonishing.
Full video: http://www.pbs.org/video/2365955827
3D Printing Helps Unlock Brain Mystery (rapidreadytech.com)
3D printing has helped some researchers at Harvard unlock the physical processes that cause the brains of large mammals to develop folds and ridges.
The outer layer of the human brain (the cerebral cortex) is lined with folds and grooves. Exactly how and why the brain grows and develops folds in that manner has puzzled scientists for years. According to the researchers, conventional wisdom held that this patterning was a purely biological phenomena.
Lakshminarayanan Mahadevan, (featured in NOVA video) a physicist and applied mathematician at Harvard, wanted to study the physics of brain development. However, there was no way to ethically study growing human brains, and the brains of typical lab animals (like rats) don’t develop folds. Using magnetic resonance imagery from a smooth fetal brain, they 3D-printed a cast to make a gel model in two layers to represent the inner “white matter” and outer “gray matter” of a brain.
They submerged the brain model in a solvent that caused the outer “cortex” layer to expand. As they observed, folds began to form on the surface. What causes this? Their theory is that the cortex wants to continue growing, but the fact that it is anchored to the underlying white matter of the brain causes it to collapse.
Mahadevan next wants to study the link between the physical process and the molecular changes going on during brain development.
“In the end, all of them are related,” Mahadevan said. “If I think about the shape of the folds in a fetal brain then yes, there are molecular processes: There are biochemical processes which cause cells to move, cause cells to divide, cause cells to change shape and cause cells to change in number.”
The research could eventually point to a better understanding of neurological conditions like autism, Alzheimer’s disease, and schizophrenia. (And perhaps paedogenesis – juvenalization – domestication?)
This research might also contribute “science” to rambling findings such as this:
(PhysOrg.com) — A new replica of an early modern human brain has provided further evidence for the theory that the human brain has been shrinking. (A rather crude description, yes?)
The skull belonged to an elderly Cro Magnon man, whose skeleton is called Cro Magnon 1. The entire skeleton was discovered in 1868 in the Cro Magnon cave in Dordogne, France, and has since become one of the most famous Upper Paleolithic skeletons. Using new technology, researchers have produced a replica of the 28,000-year-old brain and found that it is about 15-20% larger than our brains. (This is based on ONE BRAIN ENDOCAST remember!)
To produce the brain replica, called an endocast, the scientists first digitally scanned the interior of the empty skull. The images revealed the impression left by the brain on the neurocranium, which was then transformed into a 3D image. Software was then used to fabricate the brain endocast.
The researchers, including anthropologist Antoine Balzeau of the French Museum of Natural History, said that an initial assessment of Cro Magnon 1’s skull supported the theory that brains have grown slightly smaller over the past tens of thousands of years, reversing an earlier trend toward larger brains.
The finding doesn’t suggest that humans today are less intelligent than earlier humans. (Oh no! We mustn’t suggest that!) Although previous studies have found a very small relationship between brain size and intelligence, many other factors affect brain intelligence.
For instance, different parts of the brain have different functions. (But they aren’t isolated – the “parts” work together to fulfill functions) The researchers found that the Cro Magnon brain appears to have had a smaller cerebellum – the brain region linked to motor control and language – than our brains today. (Remember, this is based on ONE ENDOCAST and then compared to a generalized imaginary modern brain that all 7 billion humans today have – which is preposterous.) The researchers explain that this finding shows that some parts of the brain are more “compressible” than others, while other regions seem to provide a benefit by growing larger. (Murky and Vague!)
Although scientists don’t know for sure why our overall brains are shrinking, (I smell a statistical monstrosity behind this claim) some researchers hypothesize that our brains are becoming more efficient as they grow smaller. (Most direct and logical: skulls shrunk, thus limiting space to “house” a brain (geometry). Or lifestyles, environments, and culture over the previous 28,000 years have changed radically, so that a “big brain” or certain “functions and abilities” are less necessary today, that is, if you don’t use it, you lose it. And neoteny is a valid suspect. )
Having a large brain comes at a cost, so smaller brains have an advantage since they enable the body to use the extra energy for other purposes. On the other hand, perhaps a large skull had certain advantages for earlier people. One idea is that Cro Magnons needed large skulls because of the difficulty in chewing their food, which included lots of meat such as rabbits, foxes, and horses. Since our food has become easier to eat, we don’t need such large skulls or jaws. (But Cro-Magnon had flat faces, not jaws, teeth and muscles for processing coarse fibrous plants and raw meat)
GUESSOLOGY: Another theory (that word use again!) is that the high infant mortality rate in earlier times meant that young humans had to be physically robust (with large heads) to survive their early years. Aye, yai, yai!