https://cosmosmagazine.com/health/body-and-mind/how-adults-learn-a-new-language/?utm_so...

"Learning languages is a breeze for young children, but once that window of opportunity closes it becomes notoriously difficult. Now, Spanish scientists have shed more light on how we get around this.

"While it’s thought that language is specialised in the left side of the brain, the researchers found that the right side also helps out when learning a new language as an adult, providing further evidence of the brain’s remarkable flexibility.

“'The left hemisphere is widely considered to be more or less hardwired for language, but there is plenty of evidence that it is not quite as simple as that,” says Kshipra Gurunandan from the Basque Centre on Cognition, Brain and Language, lead author of a paper published in the Journal of Neurology.

***

“'Reading, listening and speaking activate common ‘language’ regions in the brain,” Gurunandan explains, “but they also involve the visual, auditory and motor regions, respectively, and we wanted to study the consequences for language learning.”

"To test this, they recruited 48 healthy native Spanish speakers aged 17 to 60 from language schools. The study consisted of two experiments: one compared basic and advanced level learners of the Basque language and the second looked at Spanish-Basque natives before and after a three-month language course in intermediate-level English.

***

"While speaking primarily activated language regions in the left hemisphere, results showed much greater variation in which hemisphere was activated while reading and, to a lesser degree, listening. The switch was most apparent in more advanced learners.

"This suggests reading and listening are more flexible throughout adulthood, which makes them easier to learn as people become more proficient, according to Gurunandan. It could also explain why adults can often understand a new language but struggle to speak it to the same skill level.

"It’s striking, she adds, that the switch from a native language to a new one that’s being actively learned recruits the brain’s left hemisphere but lateralises to both hemispheres with greater proficiency, which might also help people separate the two languages."

Comment: Makes sense since language involves eyes and ears.

https://medicalxpress.com/news/2017-12-mysterious-case-boy-visual-cortex.html

"The boy, the researchers told the audience, suffered major damage to his visual cortex as a result of medium-chain acyl-Co-A dehydrogenase deficiency at just two weeks old—a rare condition that results in severe damage to nerve cells due to an inability to convert some types of fats into energy. That meant the boy, who the researchers referred to as B.I., wound up without most of his visual cortex, a condition that for most people would result in cortical blindness. Cortical blindness is an odd condition in which the brain can still receive visual input, but cannot process what is seen, leaving the person with the sensation of sight without being able to actually see. But oddly enough, B.I. can see almost as well as any other boy his age.

"B.I. caught the attention of the team at Monash due to his medical history—intrigued, they sought to test the boy and his vision, and find out why he could see despite his brain injury.

"In testing B.I.'s vision, the researchers found that he was somewhat near-sighted but was otherwise fine, except for the occasional lapse when faced with false-colored objects such as a blue banana. He could play soccer, for example, and video games, and make out the difference in emotions on a person's face.

"To find out why the boy could still see, the researchers observed him in an MRI machine and watched what happened as he processed images. By focusing on the middle temporal visual area, the researchers found an enlarged visual pathway of neural fibers that ran through two areas on the back of the brain where the visual cortex resides. One of the areas called the pulvinar is normally involved in managing sensory signals, the other, called the middle temporal area, is normally involved in detecting motion. In B.I.'s case, the pathway had grown larger than normal to allow it to do the work that his visual cortex was supposed to do, allowing him to see—a form of neuroplasticity.

An image of his brain is shown here:

https://www.newscientist.com/article/2155639-a-boy-is-missing-the-vision-bit-of-his-bra...

Comment: The amazing ability of the brain's neuroplasticity is shown by this boy's brain, by adapting a totally new area to receive the signals and interpret them.

https://www.newscientist.com/article/2147696-blind-people-repurpose-the-brains-visual-a...

"People who are blind use parts of their brain that normally handle for vision to process language, as well as sounds – highlighting the brain’s extraordinary ability to requisition unused real estate for new functions.

"Neurons in the part of the brain normally responsible for vision synchronise their activity to the sounds of speech in blind people, says Olivier Collignon at the Catholic University of Louvain (UCL) in Belgium. “It’s a strong argument that the organisation of the language system… is not constrained by our genetic blueprint alone,” he says.

"The finding builds on previous research showing that the parts of the brain responsible for vision can learn to process other kinds of information, including touch and sound, in people who are blind.

***

"While they were being scanned, groups of sighted and blind volunteers were played three clips from an audio book. One recording was clear and easy to understand; another was distorted but still intelligible; and the third was modified so as to be completely incomprehensible.

"Both groups showed activity in the brain’s auditory cortex, a region that processes sounds, while listening to the clips. But the volunteers who were blind showed activity in the visual cortex, too.

"While they were being scanned, groups of sighted and blind volunteers were played three clips from an audio book. One recording was clear and easy to understand; another was distorted but still intelligible; and the third was modified so as to be completely incomprehensible.

"Both groups showed activity in the brain’s auditory cortex, a region that processes sounds, while listening to the clips. But the volunteers who were blind showed activity in the visual cortex, too.

"The blind volunteers also appeared to have neurons in their visual cortex that fired in sync with speech in the recording – but only when the clip was intelligible. This suggests that these cells are vital for understanding language, says Collignon.

"The visual cortex contains the relevant architecture, he says, to go from sound processing to language comprehension.

“'The new finding is perhaps not surprising, but it is groundbreaking,” says Daniel-Robert Chebat at the Israeli Ariel University in the West Bank. “It shows that these parts of the brain are not only recruited [to receive new kinds of input], but can adapt and modulate their response.”

"The discovery highlights how malleable our brains are, says Collignon, but he thinks there may be a limit to this. It’s unlikely that any part of the brain can eventually learn any function, he says. Instead, there may be a set of rules, laid down in our genes, which brain regions can follow."

Comment: This is further evidence of how the human brain can modify its functional areas. It allows a highly complex organ to adapt to almost any function presented to it. The brain enlarged and developed this capacity over an eight million year period, rather speedily for evolution. It development looks designed and driven.

https://medicalxpress.com/news/2017-07-neurons-everyday-life.html

"Researchers from King's College London have discovered a molecular mechanism that enables neuronal connections to change through experience, thus fuelling learning and memory formation.

"One of the most remarkable features of our brain is its ability to sense and interpret the complex environment of everyday life. To accomplish this, brain circuits undergo a process that involves experience-dependent plasticity, a fundamental mechanism through which the nervous system adapts to sensory experience and which is at the root of our capacity to learn as well as encode and retain memories.

"Previous studies have shown that a special group of neurons present in the cerebral cortex called PV+ interneurons (a population of neurons that communicate with each other through deactivating chemical and electrical signals and express a protein called parvalbumin), are able to change in response to stimulus from the environment. However, until now the cellular and molecular mechanisms regulating this adaptability were largely unknown.

"In their new study, the multidisciplinary team of researchers ...found that this adaptability is shaped by a specific protein called Brevican. Moreover, loss of this protein leads to deficits in short-term spatial memory, the part of memory responsible for remembering different locations as well as spatial relations between objects.

"Most PV+ interneurons are wrapped by a mesh of proteins called perineural nets and several studies have shown that these proteins play a critical role in the regulation of experience-dependent plasticity, learning and memory. However, the mechanisms through which these proteins mediate this process remained a mystery. In this new study, the researchers found that one of these proteins called Brevican, which is also one of the most abundant proteins found in the brain, influences neuronal plasticity, orchestrating a dedicated molecular program in response to changes from the environment. The researchers also found that this protein shapes the intrinsic properties of PV+ interneurons and sculpts their connections to other neurons. These novel findings show that Brevican is dynamically regulated by experiences coming from the environment and is fundamentally required for spatial working memory and short-term memories.

"'Perineuronal net proteins regulate cortical plasticity by acting on interneurons. When we identified some of the mechanisms underlying this regulation, I was amazed by how a single protein can act as an activity sensor, orchestrate such a complex molecular program and simultaneously influence several key cellular processes', said Dr Emilia Favuzzi."

Comment: It is one thing to have brains appear as the result of evolution, but this mechanism is highly complex, could not have happened through chance. It must be designed.

https://www.sciencedaily.com/releases/2017/06/170616102136.htm

"Stem cells persist in the adult mammalian brain and generate new neurons throughout life. A research group ...reports in the current issue of "Science" that long-distance brain connections can target discrete pools of stem cells in their niche and stimulate them to divide and produce specific subtypes of olfactory bulb neurons. This allows the "on-demand" generation of particular types of neurons in the adult brain.

"Our brain generates new neurons throughout life. A diversity of stimuli promotes stem cells in their niche to form neurons that migrate to their place of action. In an animal model Prof. Fiona Doetsch's team has now been able to show that feeding-related neurons in the hypothalamus, a brain control center for many physiological functions, stimulate a distinct type of stem cell to proliferate and mature into specific nerve cells in response to feeding.

"Stem cells reside in only a few areas of the brain. The largest reservoir is the subventricular zone, where quiescent stem cells lie closely packed together. Signals from the environment can trigger stem cells to start dividing. The stem cells in the subventricular zone supply the olfactory bulb with neurons. In rodents, almost 100,000 new neurons migrate from the stem cell niche to the olfactory bulb each day. Olfactory stimuli reaching the nose are processed in the olfactory bulb and the information is then sent to other brain regions. The closely interwoven network of diverse olfactory bulb neurons is important for distinguishing odors.

"Each stem cell has its own identity, depending on its location in the subventricular zone. While new neurons are continuously generated, whether niche signals act to control different pools of stem cells is unknown. "We have uncovered a novel long-distance and regionalized connection in the brain between the hypothalamus and the subventricular zone, and show that physiological states such as hunger and satiety can regulate the recruitment of specific pools of stem cells and in turn the formation of certain neuron subtypes in the olfactory bulb," explains Doetsch. When the animals fasted, the activity of the nerve cells in the hypothalamus decreased and with it also the rate of proliferation in the targeted stem cell population. This returns to normal levels when the animals feed again. The division of stem cells can be controlled by changing the activity of feeding-related neurons.

"The researchers reported further that the targeted stem cell subpopulation gives rise to deep granule cells in the olfactory bulb, which may provide a substrate for adaptive responses to the environment. The results of the study raise the exciting possibility that neural circuits from diverse brain regions can regulate different pools of stem cells in response to various stimuli and states."

Comment: The brain is precisely able to adapt to the animal or human activity. As an example, in the olfactory bulb new neurons are needed as odors are experienced and remembered. I assume this ability began when the first true brains formed earlier in evolution. The brain is more changeable than liver, kidney, lung, etc. It has to have this capacity in order to accommodate developing personality and thought processes handled through consciousness.

https://cosmosmagazine.com/biology/networks-form-as-brains-develop

"As children grow up – moving through adolescence and into young adulthood – their ability to control their impulses, stay organised and make decisions improves dramatically.

"According to a new study published in Current Biology, those improvements result from the development of distinct networks within the brain.

"In adolescence the brain networks become increasingly divided into distinct parts, called modules. Modules are parts of a network that are tightly connected to each other, and less connected to other parts of the network. The new evidence shows that the degree to which executive function develops during this period in part depends on the degree to which these modules are present.

"Researcher Graham Baum says the results show the brain uses “specialized units that can work together to support advanced cognitive abilities'”.

Full story: http://www.cell.com/current-biology/fulltext/S0960-9822(17)30496-7

Summary: "The human brain is organized into large-scale functional modules that have been shown to evolve in childhood and adolescence. However, it remains unknown whether the underlying white matter architecture is similarly refined during development, potentially allowing for improvements in executive function. In a sample of 882 participants (ages 8–22) who underwent diffusion imaging as part of the Philadelphia Neurodevelopmental Cohort, we demonstrate that structural network modules become more segregated with age, with weaker connections between modules and stronger connections within modules. Evolving modular topology facilitates global network efficiency and is driven by age-related strengthening of hub edges present both within and between modules. Critically, both modular segregation and network efficiency are associated with enhanced executive performance and mediate the improvement of executive functioning with age. Together, results delineate a process of structural network maturation that supports executive function in youth."

Comment: This study shows the intimate interconnection of our developing 'self' and how our brain changes to accommodate the integration of experience and responses. These changes are automatic bot also cooperative as personality develops. We do develop ourselves. Consciousness and personality are immaterial, but based on the plasticity of the brain to fully develop and experience.

https://www.sciencedaily.com/releases/2016/12/161221125505.htm

"Neurons in the brain store RNA molecules -- DNA gene copies -- in order to rapidly react to stimuli. This storage dramatically accelerates the production of proteins. This is one of the reasons why neurons in the brain can adapt quickly during learning processes.

***

"The research group of Prof. Peter Scheiffele at the Biozentrum, University of Basel, has demonstrated that neurons store a reserve stock of RNA molecules, copies of the DNA, in the cell's nucleus. These RNA molecules form the blueprint for new proteins. After a neuronal stimulus, the stored RNA molecules are mobilized in order to adjust the function of the neuron. The process of RNA synthesis (DNA copying) is very slow, especially for large genes. Thus, this newly uncovered mechanism for mobilization of stored RNAs saves time and provides new insights regarding the fast adaptation of the brain during learning processes.

"The RNA blueprint for proteins is produced by a sophisticated copying process: First, a basic RNA copy of the DNA is generated. From this copy, individual sections, so-called introns, are subsequently cut out to provide a finalized blueprint for the production of a specific protein. This process is called RNA splicing.

"So far, it was assumed, that neuronal stimuli trigger the complete process for the production of new RNA molecules. However, the team of Peter Scheiffele now discovered that neurons in the brain pre-manufacture certain immature RNA copies which are only partially spliced. These RNA molecules still contain some introns and are stored in the cell nucleus. Signals induced by neuronal stimulation trigger the splicing completion of the immature RNA molecules.

"'The copying process of the DNA, the so-called transcription, is already finalized in advance by the neurons. Hence, mature RNA molecules can be produced within minutes," explains Oriane Mauger, the first author.

"For large genes, the production of the initial version of the RNAs itself takes dozens of hours. "The fact that the RNA molecules are already available in an immature form and only need to be completed, shortens the whole process to a few minutes," says Mauger. "Since the transcription is very time-consuming, the storage of RNA means a significant time saving. This enables neurons to quickly adapt their function."

"'This study reveals a completely new regulatory mechanism for the brain," declares Scheiffele. "The results provide us with a further explanation of how neurons steer rapid plasticity processes."

Comment: Quickly learning new habits is necessary for survival in the wild. I assume this is an old mechanism in evolution, but the article does not comment. From that standpoint the process may have been implanted in the first brains since rapid adaptation is vital for survival. Saltation?

http://www.the-scientist.com/?articles.view/articleNo/47364/title/How-Experience-Shapes...

"Newly made cells in the brains of mice adopt a more complex morphology and connectivity when the animals encounter an unusual environment than if their experiences are run-of-the-mill. Researchers have now figured out just how that happens. According to a study published today (October 27) in Science, a particular type of cell—called an interneuron—in the hippocampus processes the animals’ experiences and subsequently shapes the newly formed neurons.

***

"Newborn dentate gyrus neurons, which are called granule cells, take six weeks to fully develop and integrate into the mouse brain’s existing neural networks, said Schinder. To examine these cells’ development, the team labeled newborn granule cells with red fluorescent protein in the brains of mice and then either left the animals in their regular cages (controls) or exposed them to enriched environments—cages with tunnels and other unusual objects—for different 48 hour periods. Three weeks after the new cells were labeled, the team examined their morphology and activity.

"The researchers found that in animals who had been exposed to the enriched environment during a particular period (9 to 11 days after labeling), the young granule cells had longer dendrites with evidence of increased connections with other neurons. Specifically, these cells had a greater number of dendritic spines, the sites of incoming synapses, and more detectable electrical inputs.

"Granule cells receive different inputs from surrounding neurons at different stages of their development, Schinder said, which may explain why they are apparently receptive to experiential input only within a short period (day 9 to 11), rather than throughout their development.

"The team went on to analyze these neuronal inputs more closely. Through a series of optogenetic and chemogenetic experiments, the researchers showed that mature granule cells activated their younger counterparts via intermediary cells called interneurons. Artificially stimulating either the mature granule cells or the interneurons could recapitulate the effects of environmental enrichment on the young granule cells. Moreover, the team showed that blocking the activity of the interneurons during the animals’ exposure to enriched environments prevented the expected experience-induced morphology in the young granule cells.

"'The take home message is that experience can change how these young cells are incorporating into the brain and how they are contributing to brain circuitry,” said Hongjun Song, who studies neurogenesis at the Johns Hopkins University School of Medicine in Baltimore."

Comment: This shows how experience in young animals can shape the brain's function. The amazing malleable brain. The arrival of the first. It is such an unusual cell, how did it happen? The first neuron in evolution was a major event. Saltation.

David's comment: The bolded comment is the key point. Our personalities develop on a continuum, while the working brain adapts to our needs in functional areas. We 'r us, not what the brain makes us.
> 
> dhw: I'm not at all sure that our personality and behaviours remain fixed. Experience can change people quite drastically. And of course we all know that drugs and diseases can affect the brain and thereby change both personality and behaviour. But under normal circumstances, I also feel that I am “me” and not what my brain makes “me”, and that “I” use my brain and am not used by it. We have already had several discussions about the problem of identity: just what does this “I/me” consist of? We can see the influences of nature, nurture, heredity, experience, cells etc., but ultimately, I think it boils down to materialism versus dualism. Another endlessly fascinating question, but unless there is an afterlife, I fear we shall never know the answer!-No, we won't until/if the afterlife, but the key thought still remains, we are allowed to make what our brain becomes in structure and connections.

Mono-zygote twins start out identical but their brains are different even at birth:
> 
> http://www.wsj.com/articles/brain-mutations-guarantee-our-individuality-1455810936&... 
>
> Comment:... The brain is our servant, not a controller. - Our servant or the vessel in which we inhabit? It would seem to me if it were our servant we could fully control (or learn to fully control) every aspect of our being with the brain by our wishes alone.