Ancora su vantaggi del bilinguismo

Dopo l’articolo del New York Times di qualche settimana fa (lo potete trovare a questo link) , un nuovo studio mostra i vantaggi del bilinguismo.

Bilinguismo, un’arma in più  “Il cervello è più reattivo”

Un nuovo studio della Northwestern University conferma che apprendere due o più lingue permette di destreggiarsi fra diversi stimoli senza fatica. E previene il decadimento delle facoltà cognitive di ALESSIA MANFREDI per Repubblica

ABILI giocolieri, capaci di destreggiarsi fra stimoli diversi scremando senza fatica, in automatico, informazioni rilevanti rispetto al rumore di fondo. Il cervello di chi cresce bilingue ha una marcia in più. Sono diversi gli studi che negli ultimi anni hanno portato prove dei vantaggi che regala apprendere due o più lingue fin da molto piccoli.

L’ultimo, pubblicato sui Proceedings of the National Academy of Science (Pnas), viene dalla Northwestern University in Illinois: la ricchezza dell’esperienza linguistica dei bilingui ne affina il sistema uditivo e ne migliora l’attenzione e la memoria di lavoro, una sorta di sostegno cognitivo che ci aiuta a svolgere più compiti contemporaneamente.

Viorica Marian ha studiato insieme alla neuroscienziata Nina Kraus le conseguenze del bilinguismo sul cervello, in particolare nelle aree uditive sottocorticali, che ricevono diversi stimoli dalle aree cognitive. Era già noto come lo studio della musica, un arricchimento sensoriale, migliorasse l’elaborazione del suono.

Ora Marian e Kraus, insieme ad altri colleghi, si sono chieste se l’esperienza di parlare più lingue potesse portare a modificazioni nella codifica del suono in aree evolutivamente antiche del cervello, come il tronco cerebrale. E la risposta è stata positiva, fornendo così una prova biologica dell’impatto di questa abilità acquisita sul cervello.

In pratica, nei bilingui cambia il modo in cui il cervello risponde ai suoni. “Si fanno puzzle e parole crociate per

mantenere la mente lucida”, ha spiegato la dottoressa Marian, del laboratorio di bilinguismo e psicolinguistica a scienza della comunicazione della Northwestern University. “Ma i vantaggi che abbiamo osservato in chi parla due lingue vengono in automatico, semplicemente per il fatto di conoscere e usare due idiomi”, sottolinea la studiosa. Benefici particolarmente estesi e rilevanti, che riguardano anche la capacità di attenzione, aggiunge Nina Kraus.

Lo studio è stato condotto su adolescenti bilingui, che parlavano inglese e spagnolo, e monolingui, solo inglese, sottoposti ad una serie di test in cui ascoltavano una sillaba, “da”, in condizioni diverse. In una situazione di ascolto non disturbata, le risposte neurali a suoni complessi sono risultate simili per entrambi i gruppi. Ma in presenza di rumori di fondo, il cervello dei bilingui è riuscito a distinguere caratteristiche del suono “sottili”, come la frequenza fondamentale, molto meglio rispetto ai monolingui. Parallelamente, i risultati sono stati migliori anche in compiti che richiedevano attenzione prolungata.

“Nei bilingui l’attenzione si affina grazie all’esperienza e il loro sistema uditivo diventa più efficiente nell’elaborazione automatica dei suoni”, commenta Andrea Marini, docente di Psicologia del linguaggio e della comunicazione all’Università di Udine “e la cosa interessante è che tutto avviene in modo implicito, senza alcuno sforzo”. Una palestra preziosa per il cervello, che rende migliori i risultati anche in compiti che richiedono attenzione sostenuta, non solo uditivi ma anche di tipo visivo.

In sostanza, chi è esposto a più di una lingua si trova fin da subito in una situazione di maggiore difficoltà. “Deve riconoscere fin da piccolo suoni e frequenze diverse, fa più fatica ma affina diverse qualità rispetto a chi non viene messo di fronte a questa prova, come i monolingui”, spiega ancora il professore. Con vantaggi importanti anche rispetto al decadimento delle facoltà cognitive, “come ha dimostrato uno studio canadese ¹ del 2010″, ricorda Marini, in cui si evidenziava che il bilinguismo quotidiano, non saltuario, può ritardare la comparsa dei sintomi dell’Alzheimer anche di cinque anni nelle persone anziane”. Risultato non raggiunto da alcun farmaco esistente.

Complimenti! 2000 anni dopo scoprono “mens sana in corpore sano”!

E ci volevano esperimenti su animali, anni di ricerche e plotoni di scienziati per sapere quello che si sa dai tempi dei Romani? Che l’esercizio fa bene anche allo sviluppo e alle funzionalità cerebrali e intellettuali?

Rimango sempre stupito per certe riscoperte dell’acqua calda!

Riporto l’articolo di pochi giorni fa del New York Times

How Exercise Could Lead to a Better Brain

By GRETCHEN REYNOLDS

Published: April 18, 2012

The value of mental-training games may be speculative, as Dan Hurley writes in his article on the quest to make ourselves smarter, but there is another, easy-to-achieve, scientifically proven way to make yourself smarter. Go for a walk or a swim. For more than a decade, neuroscientists and physiologists have been gathering evidence of the beneficial relationship between exercise and brainpower. But the newest findings make it clear that this isn’t just a relationship; it is the relationship. Using sophisticated technologies to examine the workings of individual neurons — and the makeup of brain matter itself — scientists in just the past few months have discovered that exercise appears to build a brain that resists physical shrinkage and enhance cognitive flexibility. Exercise, the latest neuroscience suggests, does more to bolster thinking than thinking does.

The most persuasive evidence comes from several new studies of lab animals living in busy, exciting cages. It has long been known that so-called “enriched” environments — homes filled with toys and engaging, novel tasks — lead to improvements in the brainpower of lab animals. In most instances, such environmental enrichment also includes a running wheel, because mice and rats generally enjoy running. Until recently, there was little research done to tease out the particular effects of running versus those of playing with new toys or engaging the mind in other ways that don’t increase the heart rate.

So, last year a team of researchers led by Justin S. Rhodes, a psychology professor at the Beckman Institute for Advanced Science and Technology at the University of Illinois, gathered four groups of mice and set them into four distinct living arrangements. One group lived in a world of sensual and gustatory plenty, dining on nuts, fruits and cheeses, their food occasionally dusted with cinnamon, all of it washed down with variously flavored waters. Their “beds” were colorful plastic igloos occupying one corner of the cage. Neon-hued balls, plastic tunnels, nibble-able blocks, mirrors and seesaws filled other parts of the cage. Group 2 had access to all of these pleasures, plus they had small disc-shaped running wheels in their cages. A third group’s cages held no embellishments, and they received standard, dull kibble. And the fourth group’s homes contained the running wheels but no other toys or treats.

All the animals completed a series of cognitive tests at the start of the study and were injected with a substance that allows scientists to track changes in their brain structures. Then they ran, played or, if their environment was unenriched, lolled about in their cages for several months.

Afterward, Rhodes’s team put the mice through the same cognitive tests and examined brain tissues. It turned out that the toys and tastes, no matter how stimulating, had not improved the animals’ brains.

“Only one thing had mattered,” Rhodes says, “and that’s whether they had a running wheel.” Animals that exercised, whether or not they had any other enrichments in their cages, had healthier brains and performed significantly better on cognitive tests than the other mice. Animals that didn’t run, no matter how enriched their world was otherwise, did not improve their brainpower in the complex, lasting ways that Rhodes’s team was studying. “They loved the toys,” Rhodes says, and the mice rarely ventured into the empty, quieter portions of their cages. But unless they also exercised, they did not become smarter.

Why would exercise build brainpower in ways that thinking might not? The brain, like all muscles and organs, is a tissue, and its function declines with underuse and age. Beginning in our late 20s, most of us will lose about 1 percent annually of the volume of the hippocampus, a key portion of the brain related to memory and certain types of learning.

Exercise though seems to slow or reverse the brain’s physical decay, much as it does with muscles. Although scientists thought until recently that humans were born with a certain number of brain cells and would never generate more, they now know better. In the 1990s, using a technique that marks newborn cells, researchers determined during autopsies that adult human brains contained quite a few new neurons. Fresh cells were especially prevalent in the hippocampus, indicating that neurogenesis — or the creation of new brain cells — was primarily occurring there. Even more heartening, scientists found that exercise jump-starts neurogenesis. Mice and rats that ran for a few weeks generally had about twice as many new neurons in their hippocampi as sedentary animals. Their brains, like other muscles, were bulking up.

But it was the ineffable effect that exercise had on the functioning of the newly formed neurons that was most startling. Brain cells can improve intellect only if they join the existing neural network, and many do not, instead rattling aimlessly around in the brain for a while before dying.

One way to pull neurons into the network, however, is to learn something. In a 2007 study, new brain cells in mice became looped into the animals’ neural networks if the mice learned to navigate a water maze, a task that is cognitively but not physically taxing. But these brain cells were very limited in what they could do. When the researchers studied brain activity afterward, they found that the newly wired cells fired only when the animals navigated the maze again, not when they practiced other cognitive tasks. The learning encoded in those cells did not transfer to other types of rodent thinking.

Exercise, on the other hand, seems to make neurons nimble. When researchers in a separate study had mice run, the animals’ brains readily wired many new neurons into the neural network. But those neurons didn’t fire later only during running. They also lighted up when the animals practiced cognitive skills, like exploring unfamiliar environments. In the mice, running, unlike learning, had created brain cells that could multitask.

Just how exercise remakes minds on a molecular level is not yet fully understood, but research suggests that exercise prompts increases in something called brain-derived neurotropic factor, or B.D.N.F., a substance that strengthens cells and axons, fortifies the connections among neurons and sparks neurogenesis. Scientists can’t directly study similar effects in human brains, but they have found that after workouts, most people display higher B.D.N.F. levels in their bloodstreams.

Few if any researchers think that more B.D.N.F. explains all of the brain changes associated with exercise. The full process almost certainly involves multiple complex biochemical and genetic cascades. A recent study of the brains of elderly mice, for instance, found 117 genes that were expressed differently in the brains of animals that began a program of running, compared with those that remained sedentary, and the scientists were looking at only a small portion of the many genes that might be expressed differently in the brain by exercise.

Whether any type of exercise will produce these desirable effects is another unanswered and intriguing issue. “It’s not clear if the activity has to be endurance exercise,” says the psychologist and neuroscientist Arthur F. Kramer, director of the Beckman Institute at the University of Illinois and a pre-eminent expert on exercise and the brain. A limited number of studies in the past several years have found cognitive benefits among older people who lifted weights for a year and did not otherwise exercise. But most studies to date, and all animal experiments, have involved running or other aerobic activities.

Whatever the activity, though, an emerging message from the most recent science is that exercise needn’t be exhausting to be effective for the brain. When a group of 120 older men and women were assigned to walking or stretching programs for a major 2011 study, the walkers wound up with larger hippocampi after a year. Meanwhile, the stretchers lost volume to normal atrophy. The walkers also displayed higher levels of B.D.N.F. in their bloodstreams than the stretching group and performed better on cognitive tests.

In effect, the researchers concluded, the walkers had regained two years or more of hippocampal youth. Sixty-five-year-olds had achieved the brains of 63-year-olds simply by walking, which is encouraging news for anyone worried that what we’re all facing as we move into our later years is a life of slow (or not so slow) mental decline.

Child Early Development Comes from Touching and Playing, not Media Exposure

This below is an “abridged version” of the full post available here

“Baby Einstein” is no Genius

Finally! An insidious product, cleverly marketed for over a decade to parents at the expense of our children, is being outed. But will parents wise up?

First, the good news: According to a recent article in the New York Times,“Disney Expands Refunds on ‘Baby Einstein’ DVDs,” The Walt Disney Company is widely refunding users of its ”Baby Einstein” videos in response to challenges about the legitimacy of its educational claims. For years the “Baby Einstein” packaging included assertions that the videos would encourage language development, even “[teach] words to babies under 2 years old.”

The hero in this case is The Campaign for a Commercial-Free Childhood, a Boston-based advocacy group that brought the DVD’s bogus claims to the Federal Trade Commission in 2006. It has been fighting ever since to take “Baby Einstein” to task for misleading consumers with false advertising on the product’s packaging and web site. Under FTC scrutiny and the added pressure of a threatened class-action suit, the company removed certain wording from the packaging asserting that the DVD has some positive effect on a baby’s development.

Obviously, these claims are not — nor have they ever have been — supported by scientific research. In fact, studies conclude the opposite: increased TV and video watching is linked to delayed language skills and learning disorders (not to mention obesity). Most parents are now aware that The American Academy of Pediatrics (a really smart group) warns against any media for children under the age of 2. Of course, this is “Baby Einstein’s” target audience.

Now for the bad news: recent studies show that decades of warnings against TV and video viewing for babies have had little effect on parents. A recent article in the Los Angeles Times entitled “Kids’ Eyes are Glued to TV” also covers the “Baby Einstein” marketing scam and reports grim findings: “The amount of television usage by children (has) reached an eight-year high…”

Why are parents hooked on getting kids hooked on TV? In the many papers I have read, experts assign guilt to parents without providing solutions.

Experts offer vague directives like, “Children should be playing outdoors. Watch TV with your kids. Read to your children. ”

Bingo. But none of this information is particularly helpful, because it does not offer any specific alternative to giving a baby passive entertainment when the parents need a well-deserved break. No question, parents need breaks, and the last thing they need is guilt.

Magda Gerber’s non-profit organization approach to child care is the real genius.

Picture this: our week old baby is on the changing table after a diaper change. He is looking at the ceiling, calmly and quietly. He is content. Instead of picking him up because we’re done and want to move on, we wait and watch. Five minutes go by before he looks toward us. We then say, “Okay, now I will pick you up.” Our son has just enjoyed his first session of uninterrupted play time, and he has given us a non-verbal signal that he is ready to move on.

The key to guilt-free breaks: never interrupt a contented baby.

An infant’s uninterrupted play time must be balanced with plenty of intimate one-on-one time with loved ones, and Magda Gerber encourages parents to provide focused togetherness each day while mutually accomplishing chores like diapering, feeding, and bathing. When we take advantage of these activities, rather than rushing through them to make way for ‘playtime,’ and when we give our baby undivided attention, slow down, and invite the baby to participate as much as possible, then both parent and child are refueled by the shared experience. A child who receives a parent’s full attention several times a day can then spend hours happily occupied with independent play, and give parents time for breaks.

Parents must understand that early exposure to media and other passive entertainment will immediately undermine a child’s innate ability to create play on his own and will perpetuate the very problem the parent is attempting to solve: a child who cannot occupy himself. Children are creatures of habit, and they quickly become used to a life of passivity when we expose them to media. TV and videos are harmful to a baby, period. There are no benefits.

TV and videos are a passive experience for an infant. They do not ‘learn’ from them because they do not understand them. The only way an infant does gain knowledge is by exploring the world around him with all his senses, in his own way and in his own time. This is active learning, and it is as simple as having the freedom to look around a room or examine his fingers and toes. Compare this to being strapped in a booster seat, mesmerized by meaningless words and images cascading from TV set. Surely, no sane or educated person could claim this as ‘educational’.