L’ homme et la mouche

Que l’homme prenne la mouche ne surprend personne. Que l’homme et la mouche partagent des comportements peut étonner. C’est pourtant le cas si l’on se fie aux travaux du professeur Zars[1] de l’Université du Missouri, spécialiste en neurobiologie. Le professeur Zars a étudié le comportement des mouches à fruit males, Drosophila melanogaster, et a découvert que les males privés de sexe noient leur dépit dans l’alcool : parallèle évident avec le comportement des hommes !

[1] G. Shohat-Ophir, K. R. Kaun, R. Azanchi, U. Heberlein. Sexual Deprivation Increases Ethanol Intake in Drosophila. Science, 2012; 335 (6074): 1351 DOI: 10.1126/science.1215932

Les trous noirs auraient-ils un cœur?

Les trous noirs,  objets célestes ô combien mystérieux puisque les lois physiques n’ont plus de sens en leur intérieur, auraient-ils un cœur, un pouls?

Un doctorant de Harvard, Joey Nielsen et ses collègues, ont étudié les émissions de rayons X du trou noir GRS1915+105.Celui-ci se trouve dans la Voie Lactée et dispose d’une étoile comme compagnon  et garde-manger dans lequel il puise son alimentation en gaz et particules.

En combinant les observations de ce trou noir faites par deux satellites, Chandra et Rossi (RXTE), Nielsen et son équipe ont découvert que le trou noir émet des pulsations en rayons X toutes les 50 secondes variant en intensité d’un facteur de 1 à 3.Il se trouve que ce rythme, quoiqu’un peu plus lent, ressemble fort au rythme cardiaque tel qu’il apparait sur les électrocardiogrammes de cœurs humains! De là, Nielsen et son directeur de thèse, le professeur Julia Lee, ont pu mesurer le montant de matière absorbé puis rejeté par le trou noir à chaque battement.

Pour plus amples détails : Chandra X-ray Center (2011, January 14). Taking the pulse of a black hole system. ScienceDaily. Retrieved January 14, 2011, from http://www.sciencedaily.com­ /releases/2011/01/110112175523.htm

Bilingualism: boon or bane?

In this weekend’s New York Times Magazine, Guy Deutscher, author of « Through the Language Glass: Why the World Looks Different in Other Languages », reviewed the current state of research to answer the question: » Does your Language Shape How You Think? » Mr.Deutscher gives interesting examples showing that language does indeed compel the speakers to express thoughts in a particular way or to provide the listener with certain information, whether about the gender as in French or German as opposed to English or about how the speaker came to know the facts they are reporting as for the Matses in Peru. Click here to read the article.

As the first bilingual French-English charter school in New York City, the New York French American Charter School, will open in September ,2010 we may well ask, following Mr. Deutscher’s inquiries, whether bilingualism shapes how the speakers think, whether there are any benefits, aside from the obvious cultural ones, to learning another language from the earliest age? Wouldn’t such bilingualism overtax the abilities of some children and render them less proficient in both languages? To answer some of the questions one may have about bilingualism, I did a cursory ,and wholly unscientific, survey of the literature in the last 3 years and share here what caught my attention.

What are the benefits of an early bilingual education?

According to studies of kindergartners done at Harvard by Prof.Silverman[1] pupils who speak another language at home and who learn English as a second language acquire a general vocabulary in English at a faster rate than English-only pupils of the same age.

Early bilinguals are able to learn another language faster than monolinguals and are better able to learn new words in their own language as shown by Viorica Marian and Margarita Kaushanskaya, professors of communication science at Northwestern University[2].

Professors Marian and Kaushanskaya’s research also answers a question many parents have when deciding whether to educate their children bilingually: will bilingual education confuse or slow down my child’s learning? In their article « Bilingualism reduces native-language interference during novel-word learning »[3], they show that bilinguals are better able than monolinguals to filter out « noise »-irrelevant information- when learning a new language.Accordingly, bilingual education from an early age helps rather than hinders a child’s development.

Parents may be wondering if it is worth going to the trouble of providing an early bilingual education to their offsprings if the child then loses the second language through lack of use. Recent research by Bristol University researchers[4] suggests that people who were exposed to another language when young not only relearn the forgotten language more rapidly but retain the ability to pronounce difficult sounds of the second language. They used Hindi and Zulu as second languages because these languages have phonemes –sound units- that are very difficult for native English speakers to recognize and reproduce. They found that the subject quickly relearnt to recognize and pronounce those foreign phonemes. We have all observed cases of people who lost a language learnt as a child who, when relearning it as adults, are able to pronounce it like native speakers.

Monolingual education of children from homes where another language is spoken has another very real negative impact on the construction of the child’s identity, language learning and critical thinking development as Elena Constantinou, doctoral student at the University of Leicester showed in her June 24,2010 presentation « Exclusion of mother tongue problematises identity construction » at the Festival of Postgraduate Research of the University[5].

How early should bilingual education start?

The short answer is as early as possible, even during pregnancy! As shown by psychologists Krista Byers-Heinlein, and Janet Werker (University of British Columbia) and Tracey Burns of the OECD who studied mothers speaking both English and Tagalog during pregnancy[6] and mothers who spoke only English, monolingual babies were only interested in English whereas bilingual babies showed no preference for one language or the other suggesting that those infants have a predisposition for bilingual learning.

Their research showed also that infants are able to discriminate between the two languages and to keep them apart. This research extends the earliest age at which infants can tell apart two languages. A previous study showed that 4- and 6-month-old infants can discriminate languages (English from French) just from viewing silently presented articulations. By the age of 8 months, only bilingual (French-English) infants succeed at this task.[7]

Bilingualism’s impact on brain structure and use of brain resources

« Can early language exposure modify neural tissue? Does extensive and maintained exposure to two languages from early life leave a « bilingual signature » on the human brain? How do bilinguals avoid confusing their two languages as they rapidly process their languages and /or move from one language context to another? Do early proficient bilinguals process language differently from monolinguals and recruit different neural tissue across all contexts, including one language at a time and two languages in rapid alternation?[8] Or do such bilinguals process language similarly to monolinguals and recruit similar neural tissue but not across all contexts?[9] » These are the questions that Professor Ioulia Kovelman and her co-workers set out to answer using novel neuro-imaging techniques[10].Her conclusions are well worth quoting in full:

« Early and extensive dual language exposure appears to have an impact on how the bilingual brain processes language within classical language areas (IFC, BA) as well as brain areas that support language processing (DLPFC, BA46/9 and IFC BA 47/11).The overall implication is that this neural change is entirely positive-bilinguals can read and listen to semantic information in each of their languages with the same effectiveness as monolinguals. The bilingual brain also develops mechanisms that allow for successful processing of two languages concurrently in a bilingual mode. We therefore hope that scientists, educators and bilingual policymakers, alike, will take notice of the present findings-especially those who decide on educational settings for the nation’s young bilinguals and whether early bilingual language learning as a child harms one’s dual language, reading, and cognitive processing as an adult. To be sure, we found no evidence of harm and instead found evidence that the bilingual brain processes each of the two languages with the aplomb of a monolingual brain processing one. »[11]

These results were confirmed in a study carried out by Professor Ibrahim of the Department of Learning Disabilities of Haifa University[12] who investigated whether one or both languages of an Arabic-Hebrew bilingual individual are disrupted following brain damage. In this case, his investigation led to the conclusion that the Arabic and Hebrew language capabilities of the patient resided in two different areas of the brain even though the two languages are semantically very close.[13]

Are there any benefits of bilingualism in adulthood?

Indubitably yes. Indeed, Alzheimer’s has been shown by Prof. Bialystok to be delayed by an average of four years in bilinguals versus monolinguals[14].Similarly, Dr.Gilit Kavé and her co-workers at the Herczeg Institute on Aging at Tel Aviv University have shown that senior citizens who speak several languages show less mental aging than monolinguals: the more languages you speak the better your cognitive states are when you get older. The study was conducted on people between the ages of 75 and 95.[15]

Last, but not least, according to a 2009 report by research team appointed by the European Commission entitled « The Contribution of Multilingualism to Creativity »[16], click here to read the Report, multilinguals show superior performance in handling complex and demanding problem-solving tasks, higher creativity and mental flexibility compared to monolinguals.

©2010 Pierre F. de Ravel d’Esclapon

[1]Elementary School Journal, 107(4), 365-383 (2007): Rebecca Deffes Silverman: »Vocabulary Development of English-Language and English-Only Learners in Kindergarten ».

[2] « The Bilingual Advantage in Novel Word Learning » (2009) Psychonomic Bulletin & Review,   16, 705-710.

[3] J Exp Psychol Learn Mem Cogn. 2009 May; 35(3):829-35.

[4] J.Bowers,S.Mattys and S.Gage « Preserved Implicit Knowledge of a Forgotten Childhood Language » Psychological Science 2009;20(9):1064

[5] http://www2.le.ac.uk/ebulletin/news/press-releases/2010-2019/2010/06/nparticle.2010-06-09.4016247525. While her research focused on children whose home language is the Cypriot dialect, her findings should apply to other communities as well.

[6] Byers-Heinlein, K., Burns, T.F., & Werker, J.F. ( 2010). « The roots of bilingualism in newborns ». Psychological Science, 21(3), 343-348,(2010) doi: 10.1177/0956797609360758

[7]« Visual Language Discrimination in Infancy » Whitney M. Weikum, Athena Vouloumanos, Jordi Navarra, Salvador Soto-Faraco, Núria Sebastián-Gallés, and Janet F. Werker Science 25 May 2007:Vol. 316. no. 5828, p. 1159 DOI: 10.1126/science.1137686.

[8] The neuroscientists refer to this as the Neural Signature Hypothesis

[9] This is the so-called Functional Switching Hypothesis.

[10] « Shining New Light on the Brain’s « Bilingual Signature »: a Functional Near Infrared Spectroscopy Investigation of Semantic Processing » I. Kovelman, M.H. Shalinsky, M.S.Berens and L.Petitto  Neuroimage 39(2008) 1457-1471.To read the article click here.Interested readers may also enjoy her other papers:« Age of first bilingual language exposure as a new window into bilingual reading development« Bilingualism: Language and Cognition 11 (2), 2008, 203–223 ; »Dual language use in sign-speech bimodal bilinguals: fNIRS brain-imaging evidence« Brain & Language 109 (2009) 112–123;L.Petitto « New Discoveries From the Bilingual Brain and Mind Across the Life Span: Implications for Education »MIND, BRAIN, AND EDUCATION vol.4

[11] Id.p.1468.

[12] « Selective deficit of second language: a case study of a brain-damaged Arabic-Hebrew bilingual patient » Behavioral and Brain Functions 2009, 5:17doi:10.1186/1744-9081-5-17

[13] Interested readers will benefit from studying the literature quoted in Professor Ibrahim’s footnotes.

[14] « Bilingualism as a protection against the onset of symptoms of dementia » Bialystok E., Craik F.I. & Freedman M. Neuropsychologia 45(7),2007 ,459-464

[15] Kavé, G., Eyal, N., Shorek, A., & Cohen-Mansfield, J. (2008). Multilingualism and cognitive state in the oldest old. Psychology and Aging, 23(1), 70-78.

[16] EC Public Service Contract No EACEA/2007/3995/2 16 July 2009

Expatriés: votre accent vous rend-il moins crédible?

Selon les recherches effectuées par Boaz Keysar, professeur de psychologie à l’Université de Chicago et par le chercheur  Shiri Lev-Ari de la même université la réponse est affirmative aux Etats-Unis. C’est ce qui ressort de l’article qu’ils viennent de publier dans le denier numéro du Journal of Experimental Social Psychology [1]intitulé « Why Don’t We Believe Non-Native Speakers? The influence of Accent on Credibility »

Pour découvrir cette conséquence insidieuse de l’accent, ils ont fait lire le même texte par des locuteurs de langue maternelle anglaise et par des locuteurs dont l’anglais n’est pas la langue maternelle. Une des phrases utilisée était : »A giraffe can go without water longer than a camel can ».Bien que les américains évaluant la crédibilité des locuteurs aient été prévenus que l’information contenue dans la phrase ne reflétait par les connaissances personnelles des locuteurs, l’expérience a démontré que les américains évaluant la crédibilité des locuteurs ont estimé que plus l’accent était fort, moins le locuteur était crédible. Selon le professeur Keysar, plus l’accent est prononcé moins l’auditeur comprend et plus il a tendance à attribuer la difficulté de compréhension à un manque de crédibilité du locuteur.

Ne faut-il pas tirer des leçons de ces recherches pour la composition des jurys, au pénal comme au civil, en fonction de la sévérité de l’accent des témoins? L’appréciation de telles recherches ne devrait-elle pas faire partie de la formation des juges?

Il serait intéressant de savoir si les résultats obtenus par MM. Keysar et  Lev-Ari avec des évaluateurs américains seraient les mêmes si l’expérience était menée d’abord entre américains parlant avec un fort accent régional-un locuteur avec un fort accent du Tennessee ou de l’Alabama est-il perçu comme moins crédible par un auditeur du Maine et vice versa- et ensuite avec des personnes de langue française devant évaluer la crédibilité de locuteurs dont le français n’est pas la langue maternelle[2]. Selon les résultats, on peut envisager un vaste chantier de réflexion sur la façon dont les  sociétés perçoivent et traitent les immigrants.

[1] Journal of Experimental Social Psychology,2010;DOI:10.1016/j.esp.2010.05.025

[2] Le lecteur pourra également consulter les travaux des professeurs Rafiq Ibrahim, Mark Leikin et Zohar Eviatar de l’Université de Haïfa Ibrahim, R., Eviatar, E., & Leikin, M. (2008). » Speaking Hebrew with an accent: Empathic capacity or other non-personal factors. » International Journal of Bilingualism, 12(3), 195-207 et Leikin, M., Ibrahim, R., Eviatar, Z., & Sapir, S. (2009). « Listening with an accent: Speech perception in a second language by late bilinguals ». Journal of Psycholinguistic Research, 38, 447-457.

Jeu mathématique #2

Un cas de jurisprudence en Californie il y a quelques années soulève un problème mathématique intéressant Voulant attirer dans ses rêts les gros joueurs, un casino avait recruté un joueur professionnel aux conditions suivantes: vous disposez de jetons d’une valeur de $ 5 millions pour “flamber” dans notre casino. Tout ce que vous gagnez au delà de 5 millions vous est acquis et si vous perdez les 5 millions vous ne nous devez rien. Il joua et perdit tout. Comme de bien entendu, le fisc s’en est mêlé arguant qu’il devait l’impôt sur un revenu de $ 5 millions. En première instance, le tribunal s’est rangé à l’avis du fisc mais en appel, la cour a cassé, raisonnant que les $ 5 millions ne constituaient pas  réellement un revenu entre les mains du joueur e t  et celui-ci   ne devait donc pas d’impôt sur le revenu sur ces $ 5 millions.

D’un point de vue strictement mathématique, faisant l’hypothèse que le joueur jouait au casino la stratégie lui donnant les meilleures chances contre le casino ( le “pass-line bet” au jeu de “craps”,en arrondissant, donne 50,3% pour le casino  et 49,7% pour le joueur et paye $1 pour chaque $1 joué si le joueur gagne) la décision de la cour d’appel était-elle justifiée? En d’autres termes, dans l’hypothèse précitée, la mise à disposition de $5 millions avait-elle néanmoins une valeur?

Supposons maintenant qu’un joueur décavé en est à son dernier billet de $100 et qu’il lui faut $200  pour pouvoir rentrer chez lui, somme qu’il ne veut pas, pour des raisons évidentes, demander à sa chère et tendre. Prenant pour acquis qu’il va jouer la stratégie du pass line bet avec à chaque fois 49,7% de chances de gagner et l’espérance de toucher une somme égale à sa mise s’il gagne, quelle est sa stratégie optimale s’il veut gagner juste assez pour rentrer chez lui: jouer $5 chaque fois,$20 chaque fois ? De la réponse, mathématiquement justifiée, quelles conclusions peut-on  tirer sur les stratégies optimales à adopter  pour maximiser ses chances de gagner   dans un jeu à somme zéro où l’on est soit le joueur le plus fort soit le joueur le plus faible?

Réponse au jeu mathématique #1

Il s’agissait de déterminer, de tête de préference et en tous les cas sans calculatrice ou ordinateur ,quel est le plus grand des nombres entre:

Cas 1: Eqn001 et Eqn002,cas 2 :  Eqn019et  Eqn007,cas 3:, Eqn014,Eqn019et Eqn007

Aucun de mes amis sortis des grandes écoles scientifiques ne m’a envoyé l’élégante solution qui permet,au moins pour les cas 1 et 2 de trouver de tête la solution.Silence également de la part de mes lecteurs anonymes.

Voici donc la solution:les 3 racines peuvent s’écrire ,Eqn008,Eqn009et Eqn010 .Dans tous les cas,il suffit de trouver le plus grand commun diviseur  (pgcd) des exposants (rappelons nous les cours d’arithmétique de Math Elem! ).Ainsi,pour le cas 1,il suffit de monter à la puissance du pgcd (2,3)=6 soit,Eqn012 et Eqn011.Comme 9 est plus grand que 8 ,il s’en suit que  Eqn019> Eqn014.Pour le cas 2, Eqn015= Eqn016= 243 et Eqn017=Eqn018=125 donc  Eqn019>Eqn004.Voila!

P.S. Pour le cas 3,l’emploi d’une feuille de papier est permis!

In vino sanitas: the French paradox

The French are known to enjoy wine and to eat a rich diet featuring such delicacies as foie gras, sweetbread or kidneys.Yet, on average, the French have a lower incidence of cardiovascular disease than teetotalers: this is what medical researchers call the French paradox explained by the red wine consumption of the French. For a number of years, it has been known that the molecule responsible for the French paradox is resveratrol, a naturally occurring molecule in wine which acts as an anti-oxidant[1].Resveratrol was isolated in 1940 by Professor Tokoaka in white hellebore, showing how good an intuition La Fontaine had when his rabbit suggested to the tortoise that it should eat some white hellebore to restore its sanity put in question by the tortoise’s challenge to the rabbit to a foot race!

Researchers from the University of the Basque Country have now shown yet another benefit of resveratrol by demonstrating its beneficial action in the reduction of fat accumulation in the liver for reasons other than alcoholism[2] .It was known that the consumption of red wine reduces the risk of lung cancer[3],protect the prostate (those who drink 4-7 glasses of red wine per week have half the risk of prostate cancer of non-drinkers)[4],and, at least for men ( a way of thanking Noah for having planted a vineyard[5]?),can add 5 years to the life expectancy[6] (half a glass a day versus no drinking at all).According to researchers from the Yale School  of Public Health, patients with non-Hodgkin’s lymphoma who drink wine have have a better survival rate after 5 years than non-drinkers, that those patients who have been drinking wine for at least 25 years before being diagnosed have  25-35%less risk of relapse, death or development of secondary cancer than non-drinkers 5 years after and that if the cancer is a B-cell lymphoma the risk difference is 60%[7].A recent  study carried out at the Cornell School of Medicine shows that this splendid molecule greatly reduces the formation of plaques, thought to be responsible for Alzheimer’s, in the brains of the tested animals[8].The action on plaques might be due to the chelation of copper. According to Professor Greenberger, Head of the Radiation Oncology Department of the Scholl of Medicine at the University of Pittsburgh, resveratrol in acetylated form may offer protection against radiation exposure[9].

Last, but not least, a study of food consumption patterns of wine and beer drinkers in Danemark,France and the United States, published in the British Medical Journal [10]in 2006 shows that wine drinkers have better dietary habits than beer drinkers. Wine drinkers eat more fruits, vegetables, olives (for extra dry martinis?), white meat and use less fat in cooking than beer drinkers. Beer drinkers buy more prepared foods, chips, cold cuts, sausages, butter and margarine and soft drinks!

Resveratrol laudamus te!

[1] Some think the molecule’s action is due to the activation of the Sirtuin 1 gene: Lagouge M, Argmann C, Gerhart-Hines Z, et al (December 2006). « Resveratrol improves mitochondrial function and protects against metabolic disease by activating SIRT1 and PGC-1α« . Cell 127 (6): 1109–22.

[2] Basque Research (2009, May 13). Two Glasses Of Wine A Day Helps To Reduce Quantity Of Fat In Liver. ScienceDaily. Retrieved May 13, 2009, from http://www.sciencedaily.com­ /releases/2009/05/090512111157.htm. Ms Elizabeth Hijona Muruamendiaraz  experimented on mice suffering from non-alcoholic hepatic esteatosis.For additional references on the beneficial action of resveratrol on liver fonctions :cf. University of California, San Diego Health Sciences (2008, May 22). Daily Glass Of Wine Could Improve Liver Health. ScienceDaily. Retrieved May 13, 2009, from http://www.sciencedaily.com­ /releases/2008/05/080520162239.htm

[3] American Association for Cancer Research (2008, October 7). Red Wine May Lower Lung Cancer Risk. ScienceDaily. Retrieved May 13, 2009, from http://www.sciencedaily.com­ /releases/2008/10/081007073922.htm

[4] Harvard Men’s Health Watch (2007, May 26). Red Wine Protects The Prostate, Research Suggests. ScienceDaily. Retrieved May 13, 2009, from http://www.sciencedaily.com/releases/2007/05/070525215203.htm ; University of Alabama at Birmingham (2007, September 1). Red Wine Compound Shown To Prevent Prostate Cancer. ScienceDaily. Retrieved May 13, 2009, from http://www.sciencedaily.com­ /releases/2007/08/070831131320.htm

[5] Gen.9:20

[6] BMJ-British Medical Journal (2009, April 30). Half A Glass Of Wine A Day May Boost Life Expectancy By Five Years. ScienceDaily. Retrieved May 13, 2009, from http://www.sciencedaily.com­ /releases/2009/04/090429205609.htm

[6] American Association for Cancer Research (2009, April 24). Drinking Wine May Increase Survival Among Non-Hodgkin’s Lymphoma Patients. ScienceDaily. Retrieved May 13, 2009, from http://www.sciencedaily.com­ /releases/2009/04/090421154322.htm

[7] BMJ-British Medical Journal (2009, April 30). Half A Glass Of Wine A Day May Boost Life Expectancy By Five Years. ScienceDaily. Retrieved May 13, 2009, from http://www.sciencedaily.com­ /releases/2009/04/090429205609.htm

[7] American Association for Cancer Research (2009, April 24). Drinking Wine May Increase Survival Among Non-Hodgkin’s Lymphoma Patients. ScienceDaily. Retrieved May 13, 2009, from http://www.sciencedaily.com­ /releases/2009/04/090421154322.htm

[8] Karuppagounder SS, Pinto JT, Xu H, Chen HL, Beal MF, Gibson GE (November 2008). « Dietary supplementation with resveratrol reduces plaque pathology in a transgenic model of Alzheimer’s disease ». Neurochem Int. 54: 111.

[9] [9] University of Pittsburgh Schools of the Health Sciences (2008, September 24). Plant Antioxidant May Protect Against Radiation Exposure. ScienceDaily. Retrieved May 13, 2009, from http://www.sciencedaily.com­ /releases/2008/09/080923181110.htm

[10] BMJ-British Medical Journal (2006, January 20). Wine Drinkers Have Healthier Diets Than Beer Drinkers. ScienceDaily. Retrieved May 13, 2009, from http://www.sciencedaily.com­ /releases/2006/01/060119232848.htm