All things brain...

[Recusant]

I don't like to make fun of mental or neurological illnesses so I didn't post this in any of the zombie, COVID or political threads, but you want to see something truly strange, look up Cotard's Syndrome.   

Sounds highly unpleasant.

[Recusant]

According to this study, the precursors of the arcuate fasciculus (a part of the brain that is important to human use of language) appeared much earlier than had been thought.

"Origins of human language pathway in the brain at least 25 million years old" | ScienceDaily

Scientists have discovered an earlier origin to the human language pathway in the brain, pushing back its evolutionary origin by at least 20 million years.

Previously, a precursor of the language pathway was thought by many scientists to have emerged more recently, about 5 million years ago, with a common ancestor of both apes and humans.

For neuroscientists, this is comparable to finding a fossil that illuminates evolutionary history. However, unlike bones, brains did not fossilize. Instead neuroscientists need to infer what the brains of common ancestors may have been like by studying brain scans of living primates and comparing them to humans.

Professor Chris Petkov from the Faculty of Medical Sciences, Newcastle University, UK the study lead said: "It is like finding a new fossil of a long lost ancestor. It is also exciting that there may be an older origin yet to be discovered still."

The international teams of European and US scientists carried out the brain imaging study and analysis of auditory regions and brain pathways in humans, apes and monkeys which is published in Nature Neuroscience.

They discovered a segment of this language pathway in the human brain that interconnects the auditory cortex with frontal lobe regions, important for processing speech and language. Although speech and language are unique to humans, the link via the auditory pathway in other primates suggests an evolutionary basis in auditory cognition and vocal communication.

Professor Petkov added: "We predicted but could not know for sure whether the human language pathway may have had an evolutionary basis in the auditory system of nonhuman primates. I admit we were astounded to see a similar pathway hiding in plain sight within the auditory system of nonhuman primates."

The study also illuminates the remarkable transformation of the human language pathway. A key human unique difference was found: the human left side of this brain pathway was stronger and the right side appears to have diverged from the auditory evolutionary prototype to involve non-auditory parts of the brain.

[Continues . . .]

Hat-tip  to xSilverPhinx for the following link to the full paper:

"Primate auditory prototype in the evolution of the arcuate fasciculus" | Nature Research

[Dark Lightning]

It's just amazing that they can pick that information out of a fossil. Some smart people there!

[xSilverPhinx]

I was unable to find an open access version of the paper.

Can you visualize it using this link?

https://www.researchgate.net/publication/340792504_Primate_auditory_prototype_in_the_evolution_of_the_arcuate_fasciculus

[Recusant]

I was unable to find an open access version of the paper.

Can you visualize it using this link?

https://www.researchgate.net/publication/340792504_Primate_auditory_prototype_in_the_evolution_of_the_arcuate_fasciculus

Yes I can, thank you, xSilverPhinx. That was a relatively readable paper, I thought. (Once I'd zoomed my screen to be able to make out the text.) A lot of cool information in there, and I learned a couple of new terms: tonotopy and, tractogram.

I'll edit the OP now.

[Recusant]

It's just amazing that they can pick that information out of a fossil. Some smart people there!

This research was done with MRI and associated techniques. I'm not sure they could have made a similar discovery using fossils. Some interesting things have been learned using endocasts from fossil skulls though.

[xSilverPhinx]

...tractogram...

Damn, that brings back memories.  There was a question in the masters entrance exam neuroanatomy section asking us to differentiate between nerves and tracts. Or something like that.

It would have been really easy if it hadn't been for the existence of the optic nerve protruding from the central nervous system. There is also an optic tract but I didn't know at the time where one ends and the other begins. Pesky optic nerve is there just to confuse people taking an entrance exam. 

[xSilverPhinx]

They wouldn't be able to make that specific discovery using fossils because the arcuate fasciculus is a nerve tract inside the brain, here's a pic of the tract with the neocortex (outer layer) removed to expose it:



As I understand it, an endocast of a high-quality fossil would shed light on area distributions of the outer layer, but not deeper structures. In that way, it's sort of like an EEG. You don't use EEG to study deep brain structures. 

[Dark Lightning]

It's just amazing that they can pick that information out of a fossil. Some smart people there!

This research was done with MRI and associated techniques. I'm not sure they could have made a similar discovery using fossils. Some interesting things have been learned using endocasts from fossil skulls though.

Oops, you're right.  I read it right, just reported back poorly.

[Tank]

I just love this thread 

[billy rubin]

They wouldn't be able to make that specific discovery using fossils because the arcuate fasciculus is a nerve tract inside the brain, here's a pic of the tract with the neocortex (outer layer) removed to expose it:

there's been some work in soft tissue fossiliztion. its rare, because the soft stuff is rarely preserved from the elemnts long enough to begin th eprocess. but it does happen.

Abstract
Some of the most remarkable fossils preserve cellular details of soft tissues. In many of these, the tissues have been replaced by calcium phosphate. This process has been assumed to require elevated concentrations of phosphate in sediment pore waters. In decay experiments modern shrimps became partially mineralized in amorphous calcium phosphate, preserving cellular details of muscle tissue, particularly in a system closed to oxygen. The source for the formation of calcium phosphate was the shrimp itself. Mineralization, which was accompanied by a drop in pH, commenced within 2 weeks and increased in extent for at least 4 to 8 weeks. This mechanism halts the normal loss of detail of soft-tissue morphology before fossilization. Similar closed conditions would prevail where organisms are rapidly overgrown by microbial mats.

https://science.sciencemag.org/content/259/5100/1439


in the past all the interior material was always cleared away from the bones and discarded. then 20 years ago somemone thought he identified a preserved dinosaur heart inside the ribcage. it was a mistake, but since then theve found fish heearts-- in brazil

https://theconversation.com/the-first-fossilised-heart-ever-found-in-a-prehistoric-animal-57204


its not very delicate, though. anything in nerveous syustem would be a stretch.

[Recusant]

...tractogram...

Damn, that brings back memories.  There was a question in the masters entrance exam neuroanatomy section asking us to differentiate between nerves and tracts. Or something like that.

It would have been really easy if it hadn't been for the existence of the optic nerve protruding from the central nervous system. There is also an optic tract but I didn't know at the time where one ends and the other begins. Pesky optic nerve is there just to confuse people taking an entrance exam. 

Nonetheless you made it over that hurdle. 

[xSilverPhinx]

...tractogram...

Damn, that brings back memories.  There was a question in the masters entrance exam neuroanatomy section asking us to differentiate between nerves and tracts. Or something like that.

It would have been really easy if it hadn't been for the existence of the optic nerve protruding from the central nervous system. There is also an optic tract but I didn't know at the time where one ends and the other begins. Pesky optic nerve is there just to confuse people taking an entrance exam. 

Nonetheless you made it over that hurdle. 

[xSilverPhinx]

They wouldn't be able to make that specific discovery using fossils because the arcuate fasciculus is a nerve tract inside the brain, here's a pic of the tract with the neocortex (outer layer) removed to expose it:

there's been some work in soft tissue fossiliztion. its rare, because the soft stuff is rarely preserved from the elemnts long enough to begin th eprocess. but it does happen.

Abstract
Some of the most remarkable fossils preserve cellular details of soft tissues. In many of these, the tissues have been replaced by calcium phosphate. This process has been assumed to require elevated concentrations of phosphate in sediment pore waters. In decay experiments modern shrimps became partially mineralized in amorphous calcium phosphate, preserving cellular details of muscle tissue, particularly in a system closed to oxygen. The source for the formation of calcium phosphate was the shrimp itself. Mineralization, which was accompanied by a drop in pH, commenced within 2 weeks and increased in extent for at least 4 to 8 weeks. This mechanism halts the normal loss of detail of soft-tissue morphology before fossilization. Similar closed conditions would prevail where organisms are rapidly overgrown by microbial mats.

https://science.sciencemag.org/content/259/5100/1439


in the past all the interior material was always cleared away from the bones and discarded. then 20 years ago somemone thought he identified a preserved dinosaur heart inside the ribcage. it was a mistake, but since then theve found fish heearts-- in brazil

https://theconversation.com/the-first-fossilised-heart-ever-found-in-a-prehistoric-animal-57204


its not very delicate, though. anything in nerveous syustem would be a stretch.

Cool stuff, billy rubin!

[Recusant]

Hippocampus, we're looking at you.

"How does the brain link events to form a memory? Study reveals unexpected mental processes" | ScienceDaily

A woman walking down the street hears a bang. Several moments later she discovers her boyfriend, who had been walking ahead of her, has been shot. A month later, the woman checks into the emergency room. The noises made by garbage trucks, she says, are causing panic attacks. Her brain had formed a deep, lasting connection between loud sounds and the devastating sight she witnessed.

This story, relayed by clinical psychiatrist and co-author of a new study Mohsin Ahmed, MD, PhD, is a powerful example of the brain's powerful ability to remember and connect events separated in time. And now, in that new study in mice published today [May 8] in Neuron, scientists at Columbia's Zuckerman Institute have shed light on how the brain can form such enduring links.

The scientists uncovered a surprising mechanism by which the hippocampus, a brain region critical for memory, builds bridges across time: by firing off bursts of activity that seem random, but in fact make up a complex pattern that, over time, help the brain learn associations. By revealing the underlying circuitry behind associative learning, the findings lay the foundation for a better understanding of anxiety and trauma- and stressor-related disorders, such as panic and post-traumatic stress disorders, in which a seemingly neutral event can elicit a negative response.

[Continues . . .]