If at First You Don’t Succeed, Sit Back and Listen

Brain

Few of us remember how easily we learned language as children. Although the acquisition wasn’t always graceful then—‘awry’ never sounds the same way aloud as the way I read it in my head— using our primary language as an adult is as habitual as tying shoelaces and seemingly as instinctual as smiling. Given how involuntarily we adults use our primary language, it’s shocking how difficult learning new languages as an adult can be. The authors of a recent PLOS ONE paper postulated that the very functions we develop as our brains mature as adults may be what hinder us from mastering language the way a child does. We might, in fact, be “trying” too hard.

Researchers have shown in previous studies that adults outperform children in tasks that require attentional focus and effort. This is because the regions of the brain associated with these abilities—the prefrontal and parietal cortices—develop more slowly, and as a result, these abilities become stronger as we age. In other words, adult brains develop abilities that help us “try harder.” These same capabilities may, however, interfere with our capacity to learn some aspects of language as adults, like the tricky networks that underlie grammar.

To test the limits of our adult brains, the authors of “When it hurts (and helps) to try: the role of effort in language learning” tested participants on how well they learned an artificial language. In the first experiment, participants were instructed to simply listen to the word stream. In the second experiment, participants were told to identify patterns and categories within the artificial language.

The researchers stimulated “effort” in the second experiment by tasking participants with a series of learning drills. Learners pressed buttons to indicate when they thought they had mastered a series of words or a grammar pattern. On the other hand, participants in the first group were explicitly distracted from learning. These participants colored during the experiment.

After the experiment, researchers scored both sets of participants on their ability to identify words, categories of words presented (for example: nouns), and the correct order of words in test sentences.

Based on the results of the test, the participants who were told to learn the language did not outperform the participants who merely listened in all categories. The “learners” were better than the “listeners” at identifying specific words of the artificial language, but both “learners” and “listeners” were equally successful in indicating the order patterns of words in test sentences. When it came to learning categories of words, only the listeners were significantly better than chance. The authors concluded that trying to learn may be a detriment to participants in this aspect of language learning.

Although fully developed prefrontal and parietal cortices endow adults with many advantages (think the ability to plan, reason, and problem solve, among others), according to the authors, these same adult brains may hinder us from learning some aspects of language. To become masters of the murkier depths of grammar, we may want to tap into the more intuitive methodology employed by children. In the meantime, we adults will continue to struggle with the differences between ‘who’ and ‘whom,’ ‘further’ and ‘farther,’ and the best way to retain complex information presented by grammar.

Citation: Finn AS, Lee T, Kraus A, Hudson Kam CL (2014) When It Hurts (and Helps) to Try: The Role of Effort in Language Learning. PLoS ONE 9(7): e101806. doi:10.1371/journal.pone.0101806

Image 1: Exercise Plays Vital Role Maintaining Brain Health by Saad Faruque

Category: Fun, General, Internet/Blogging | Tagged , , , , , | Leave a comment

Not Just a Pretty Face: Island Poppies Defend With Prickles

PoppyAlthough the vibrant, waifish petals of the poppy may appear inviting to the casual observer, a closer look reveals a pricklier message: Stay away! To discourage plant eaters like insects and birds from biting into their leafy appendages, many plant species protect themselves with defense mechanisms, like tougher leaves, distasteful latex, and armor made of prickles. Developing these defense features is part of a plant’s natural growth throughout its lifetime. Some plants, however, are able to activate additional protection when faced with attacking herbivores. The authors of a recent PLOS ONE paper investigated these defense mechanisms in two species of poppy currently found in Hawaii, where natural herbivores have long been extinct. The authors’ results reveal that island poppies may have more “nettle” in the face of simulated adversity than previously predicted.

The authors chose two species of poppy for testing, Argemone glauca, a species native to Hawaii, and Argemone mexicana, a species originally hailing from the North American continent and a recent inhabitant of the Hawaiian islands. Both species come pre-equipped with permanent features that may function as defense strategies. However, permanent defenses are costly to maintain for a plant: They divert energy away from other functions, like reproduction and growth, and are therefore an energy investment for the plant. To combat the cost of maintaining a full suite of permanent defenses, some plants respond to attacks from plant eaters only when they occur by activating additional defenses, known as inducible defenses. Unlike defense features that develop throughout the course of a plant’s lifetime, also known as constitutive defenses, inducible defenses are not permanent, only prompted by specific need.

In this study, the researchers simulated the need for additional defenses by subjecting the two species to various “attacks” to see how the poppies would respond. Plants were assigned to one of four random treatment groups:

  1. The control group, which received no treatment
  2. The damage group, where the authors clipped off portions of the leaves
  3. The Jasmonic acid group, where researchers sprayed the leaves with a harmful solution that inhibits growth
  4. And the combination group, where authors defoliated plants first and then sprayed them with Jasmonic acid

The researchers then allowed for two new leaves to grow to ensure that the plants had an adequate amount of time to respond.

Although neither species developed additional leaf toughness or produced more natural latex in response to treatments, both species exhibited increased prickle density on new leaves that grew after treatment. To evaluate prickle density, the authors harvested new leaves and counted all the new prickles on the surfaces of the leaves, excluding prickles found along the leaf edge. They also quantified the leaf area and performed statistical analyses to identify patterns in the various groups.

The authors found that Hawaiian native A. glauca responded more intensely to treatment by developing significantly more prickles than its continental North American counterpart, A. mexicana. The authors report that prickles for A. glauca were 20x more dense and 2.7x higher than A. mexicana.

Plant defenses are selected for over time due to snacking pressures from herbivores. On the Hawaii islands, however, natural herbivores of A. glauca, such as flightless ducks and beetles, are now extinct. The lack of natural predators for island plants has given rise to the idea that island plants have ‘gone soft’ over time. The authors consider A. glauca’s robust response to external attacks evidence that island plants may be better defended than previously thought.

Although it may be impossible to determine whether these island defenses have been selected for by herbivores of the past, no longer present, the inducibility of prickles in A. glauca and A. mexicana demonstrates that these poppies have the mettle to fight back against attackers and snackers.

For more on how herbivores and plants interact, check out this EveryONE blog post on snail mucus.

Citation: Hoan RP, Ormond RA, Barton KE (2014) Prickly Poppies Can Get Pricklier: Ontogenetic Patterns in the Induction of Physical Defense Traits. PLoS ONE 9(5): e96796. doi:10.1371/journal.pone.0096796

Image 1: Agemone glauca by Forest and Kim Starr

Category: Fun, General, Media | Tagged , , , , , | Leave a comment

PLOS launches Responding to Climate Change Collection

Today PLOS ONE launches the Responding to Climate Change Collection. At its centre is a paper published last December, “Assessing ‘Dangerous Climate Change’:  Required Reduction of Carbon Emissions to Protect Young People, Future Generations and Nature” by James Hansen and colleagues. The paper presented a disruptive call to action on climate change through cohesive, unified steps to reduce fossil fuel emissions to pre-industrial era levels.

Responding to climate change

Image Credits (clockwise from top left): Matt Rudge, Flickr.com; Vik Walker, Flickr.com; Vera Kratochvil, PublicDomainPictures.net; NASA Goddard Space Flight Center

The publication was accompanied by a call for papers for the PLOS ONE Collection, focussing on research that examines the practicalities of reducing fossil fuel emissions; returning the Earth to a state of energy balance; and climate and conservation management strategies that counter the impact of climate change and preserve natural habitats. Areas covered in the call for papers include atmospheric chemistry, alternative energy research, geoengineering, science policy, behavioural psychology, and ecosystem and habitat conservation.

“Minimizing human-made climate change requires insight across a broad science and policy spectrum, and ready access to knowledge as understanding is gained.  As an Open Access journal, PLOS ONE provides a vehicle to achieve that,” says Hansen.

The launch of the collection coincides with the publication of the first submission to the call. “Climate Exposure of US National Parks in a New Era of Change” by William B. Monahan and Nicholas A. Fisichelli of the U.S. National Park Service describes a variety of recent extreme climates in some of the nation’s most visited parks. Evaluation of data for 289 natural resource parks administered by the National Park Service shows that parks are overwhelmingly at the extreme warm end of historical temperature distributions. The authors call for intensive climate science education, and inclusion of the general public, in order to help steward parks and park resources in the face of the changing climate: “As climate shifts further outside of the historical range of variability, resistance strategies will likely become less effective and extremely difficult management decisions – with input from the public and stakeholder groups – will be required.”

The Collection also includes 8 related papers that have been published in PLOS ONE since the call was issued. The papers cover such diverse topics as stratospheric aerosol geoengineering, energy potential of bioenergy cropping systems and the impact of climate awareness on dietary choices of young adults in Finland.

Grand Canyon - Luca Galuzzi

Grand Canyon National Park has recently experienced extreme high temperatures compared to its historical range of variability and may require new management strategies to manage resources that are sensitive to changes in temperature. Image Credit: Luca Galuzzi CC BY-SA 2.5 – www.galuzzi.it

The “Responding to Climate Change” Collection remains open for new submissions. Few areas can benefit as much from the force of Open Access as climate change research: the combination of public, scientific, and governmental interest with the mounting misinformation, unsubstantiated opinions, and unsourced data make public access to original, well-reported, and peer-reviewed climate change research of utmost importance.

PLOS ONE’s wide scope and broad publication criteria make it a perfect venue to publish and collate relevant articles in these vastly differing areas of research into one place. Our hope is that by encouraging and facilitating further research, replication, and sharing of both positive and negative results, this Collection will become a catalyst for continued climate research and policy formation.

Image 1: (clockwise from top left) Matt Rudge, Flickr.com; Vik Walker, Flickr.com; Vera Kratochvil, PublicDomainPictures.net; NASA Goddard Space Flight Center

Image 2: Luca Galuzzi CC BY-SA 2.5 – www.galuzzi.it

Category: Aggregators | Leave a comment

What’s in a Look? For Wolves, Maybe Everything

 

WolvesIt’s been said that the eyes are the windows to the soul. They allow us to communicate feelings across a room, direct the attention of others, and express emotion better than words ever could.  The importance of eye contact in non-human species is well known—we’ve all heard that you shouldn’t stare a bear or angry dog in the eyes—but we don’t know a whole lot about how gaze is used between individuals of the same species. Japanese researchers took on this topic in a recent PLOS ONE article, focusing specifically on how eye contact and communication is affected by eye visibility and facial patterning around the eyes of canids.

Their research observed 25 canid species, comparing variations in facial pattern and coloring to observations about their social behavior and evolutionary history. They found that canines may use facial markers to either highlight or de-emphasize their eyes. Species with more distinguishable eyes tended to live and hunt in groups, where gaze-communication facilitates the teamwork that is necessary to bring down large prey and stay safe. Those with camouflaged eyes were more likely to live alone or in pairs, where communication with other members of their species may not be needed in the same way.

facial area maps

Using photos of each species, the authors analyzed the contrast between five areas of the canine face: pupil, iris, eyelid margin, coat around the eyes, and facial area including the eyes, as shown in the figure above. They measured contrast assuming red-green colorblindness of the observer (fun fact: canids cannot see the full spectrum of color). Species were then grouped according to the visibility of their eyes, described in the figure below:

  • Group A contained species with easily visible pupils and eye placement
  • Group B contained species with camouflaged pupils but clearly defined eye placement
  • Group C contained species with fully camouflaged eyes and pupils

group types

The authors found the strongest correlation between eye visibility and living and hunting behavior. More species in Group A, like gray wolves, live and hunt in packs, whereas more species in Groups B and C, like the fennec fox and bush dog, live and hunt alone or in pairs. Species in Group A also spend significantly more time in “gazing postures,” with their sight and body directed at another animal, an action that accentuates their focused attention to other members of the group. The genetic similarity between species was not as useful in explaining these differences, with A-type faces found in 8 of 10 wolf-like species, and in 3 of 10 red fox-like species. The authors suggest that A-type markings developed independently once these groups had evolutionarily split.

Lighter iris coloring is thought to be an adaptation to ultraviolet light in many species, similar to variations in human skin pigmentation. To determine whether this adaptation could explain the variation seen in canid iris color, the researchers compared the eye coloring of three wolf subspecies from Group A originating from arctic, temperate, and subtropical regions, to see if any differences in their lighter coloring could be attributed to geographical origin. They found that iris color did not vary significantly between the subspecies, suggesting that it may have developed to facilitate communication and not as an adaptation to specific geographical locations.

When the authors reviewed social behaviors, they found a number of social species with B- and C-type faces, the groups normally found alone or in pairs. These species are known to use acoustic or other visual signals, like a howl or the flash of a white tail, to communicate with their comrades. This allows them to skirt one possible disadvantage of gaze-communication: when prey can also identify and follow a gaze, and realize they’ve been targeted.

Gaze communication may be an important tool for other canids, including our own companions, domestic dogs. Previous studies have shown that domestic dogs are more likely to make direct eye contact with humans than wolves raised in the same setting. This could mean that after thousands of years of cohabitation, dogs see us in socially useful ways that wolves never will. Luckily for us, that means we get to see this.

Citation: Ueda S, Kumagai G, Otaki Y, Yamaguchi S, Kohshima S (2014) A Comparison of Facial Color Pattern and Gazing Behavior in Canid Species Suggests Gaze Communication in Gray Wolves (Canis lupus). PLoS ONE 9(6): e98217. doi:10.1371/journal.pone.0098217

Images 2 and 3: Figures 1 and 2 from the article

Category: Aggregators, Images | Tagged , , , , , , , | 1 Comment

PLOS ONE Publishes its 100,000th Article

PLOS ONE publishes its 100,000th article – a pretty major milestone for a journal that has seen its fair share of momentous events, and a perfect opportunity to reflect on this journey.

 PLOS ONE began seven and a half years ago. On the day of its launch – as has become the legend in the PLOS offices – there was an earthquake in the Bay Area, heralding the tremors that would be felt through the science world as a result of the disruptive innovation underway. PLOS ONE was an aspirational idea for PLOS from the very beginning: our founders always intended to launch a multi-disciplinary, broad-acceptance journal that would shake off the vestiges of the print tradition – no limits to the scope of research, number of pages, or potential growth.

And grow it did. After two years PLOS ONE had published over 4,000 articles, by four years it was the largest journal in the world, and now seven years after launch has published 100,000 articles. The revolutionary model of PLOS ONE has been emulated the world over: virtually every publisher now has its own equivalent “megajournal.”

PLOS ONE is now a major force in the scientific literature. The top 2% PLOS ONE papers (by number of views) have been collectively viewed nearly 39 million times, cited on Scopus over 80,000 times, bookmarked by Mendeley readers over 150,000 times, tweeted over 59,000 times, cited 2,800 times on Wikipedia, and recommended over 300 times on F1000 Prime.

The enduring value of PLOS ONE to the scientific process lies in the solid union between the three following factors: speed to publication, high standards of science, and unrestricted scope of research.

Speed to publication:

Faster time to publication was the founding principle of PLOS ONE. It doesn’t just entail going from submission to publication more quickly (although that is also important). It means dramatically reducing the time from an author’s decision to publish their findings to the time those results appear in public. That time is often years in the old system of review, where subjective opinions of significance and scope lead to unnecessary rejections and resubmission to different journals. With PLOS ONE, where scientific rigor alone is assessed, this time window shortens to a few months.

High standards:

PLOS ONE instituted rigorous standards from the start. As the volume exponentially increased and the quality of the submissions became more variable, these checks became more important and more rigorous. For every paper the journal staff (over 100 strong, including 14 editors) now check each of the following before a manuscript is sent for review:

  • Competing interests
  • Financial disclosures
  • Quality of English language
  • Ethical approval for animal experiments
  • IRB approval for human experiments
  • Protocols and CONSORT for clinical trials
  • PRISMA for systematic reviews and meta-analyses
  • Cell line provenance
  • Field sample provenance
  • Humane endpoints in animal studies
  • Data availability
  • Plagiarism

The care that we take in reporting and oversight is rooted in PLOS’ commitment to this editorial responsibility.

Because of these checks, every PLOS ONE citation on a researcher’s CV shows that their work has reached high standards of reporting and oversight – something that matters a great deal to funders and institutions as the need for reproducibility becomes increasingly a part of their overall mission. This is an area where we feel journals can take a lead: high standards of reporting are the best way for the scientific community to regain the trust of the public and politicians in the wake of the recent spate of failures in replicating high-profile discoveries.

Unrestricted scope:

So many of the delays in sharing results are a result of journals putting unnecessary restrictions on the scope of the research they are willing to publish. Journals often withhold the release of negative findings because they are likely to be cited less, and will therefore lower their impact factor. Or they exclude papers purely due to the application of disciplinary boundaries. In this digital age, with no space restrictions on what can be published, such artificial limits only impede the flow of information. At PLOS ONE, we have thrown out these notions and will consider vital research across all subject areas (even seemingly strange and multi-disciplinary).

A heartfelt 100k thank you

The impact of PLOS ONE on scientific publishing has been tremendous and revolutionary. The world of scientific communication is a different place because of it, and that is something PLOS and its entire community of collaborators should be proud of.

The extraordinary PLOS ONE Editorial Board, reviewers and authors – who believed in the PLOS mission to accelerate research communication and gave their own time to review, edit and revise manuscripts – were critical to this transformation and share in this milestone. To each and every one of them PLOS ONE is eternally grateful.

So here’s to the 100,000th PLOS ONE article. Though thrilled to have reached this milestone, we are even more excited to see where the next 100,000 will lead.

Category: Aggregators, Events, Media, Submissions, Topic Focus | Tagged , , , | 8 Comments

Magnifying Power to the People with the Foldscope

The microscope holds a place on the short list of inventions that have changed the world and revolutionized our understanding of science. Microscopes are crucially important public health tools, allowing workers to identify pathogens and correctly diagnose the cause of illnesses. As educational tools, they can excite and engage students, revealing a world invisible to the naked eye. And, as many people who’d love a microscope but don’t have one can tell you, they are also expensive. Millions of doctors, health workers, and patients worldwide lack the resources to benefit from this vital tool, and millions of students have never seen a microscope before. In a dramatic step to address this problem, researchers from Stanford University have designed ultra-low-cost microscopes built from an inexpensive yet durable material: paper. They recently published their designs and data in PLOS ONE.

Foldscope template

Meet the Foldscope. Borrowing from the time-honored tradition of origami, the Foldscope is a multi-functional microscope that can be assembled much like a paper doll. Users cut the pieces from a pattern of cardstock, fold it according to the printed lines, and add the battery, LED, and lens, and−voilà−a microscope. Foldscope schematicClick here to watch a video of how one is assembled. Some of their coolest features are as follows:

  • Foldscopes are highly adaptable and can be configured for bright-field and dark-field microscopy, to hold multiple lenses, or to illuminate fluorescent stains (with a special LED).

Foldscope Configurations

  • They can be designed for low or high powers and are capable of magnifying an image more than 2,000-fold.
  • They accept standard microscope slides, and the viewer can move the lens back and forth across the slide by pushing or pulling on paper tabs.
  • Users can focus the microscope by pushing or pulling paper tabs that change the lens’ position.
  • Foldscopes are compact and light, especially when compared with conventional field microscopes. They also weigh less than 10 grams each, or about the weight of two nickels.
  • They are difficult to break. You can stomp on them without doing much damage, and they can survive harsh field environments and encounters with children.

Stepping on FoldscopeWhat’s the total cost, you ask? According to authors, it’s less than a dollar.  At that price, it’s easy to imagine widespread use of Foldscopes by many who previously could not afford traditional microscopes. In this TED Talk, Manu Prakash demonstrates the Foldscopes and explains his hopes for them. The authors envision mass producing them and distributing different designs optimized for detecting the pathogens that cause specific diseases, such as Leishmaniasis and E. coli.  They could even include simple instructions for how to treat and prepare slides for specific diagnostic tests or provide pathogen identification guides to help health workers in the field make diagnoses.  This is just one way in which the ability to see tiny things could make a huge difference in the world.

Related links:

Low-Cost Mobile Phone Microscopy with a Reversed Mobile Phone Camera Lens

Community Health Workers and Mobile Technology: A Systematic Review of the Literature

Citation: Cybulski JS, Clements J, Prakash M (2014) Foldscope: Origami-Based Paper Microscope. PLoS ONE 9(6): e98781. doi:10.1371/journal.pone.0098781

Images: Images are from Figures 1 and 2 of the published paper

Category: Aggregators | Tagged , , , , | 2 Comments

Music, Language, and the Brain: Are You Experienced?

Have you ever thought about everything that goes into playing music or speaking two languages? Musicians for example need to listen to themselves and others as they play, use this sensory information to call up learned actions, decide what is important and what isn’t for this specific moment, continuously integrate these decisions into their playing, and sync up with the players around them. Likewise, someone who is bilingual must decide based on context which language to use, and since both languages will be fairly automatic, suppress one while recalling and speaking the other, all while continuously modifying their behavior based on their interactions with another listener/speaker. All of this must happen quickly enough for the conversation or song to flow and sound natural and coherent. It sounds exhausting, yet it all happens in milliseconds!

Playing music or speaking two languages are challenging experiences and complex tasks for our brains. Past research has shown that learning to play music or speak a second language can improve brain function, but it is not known exactly how this happens. Psychology researchers in a recent PLOS ONE article examined how being either a musician or a bilingual changed the way the brain functions. Although we sometimes think of music as a universal language, their results indicate that the two experiences enhance brain function in different ways.

heat map

One way to test changes in brain function is by using Event Related Potentials (ERPs). ERPs are electrical signals (brain waves) our brains give off immediately after receiving a stimulus from the outside world. They occur in fairly predictable patterns with slight variations depending on the individual brain. These variations, visualized in the figure above with the darkest red and blue areas showing the most intense electrical signals, can clue researchers into how brain function differs between individuals and groups, in this case musicians and bilinguals.

The ERP experiment performed here consisted of a go/nogo task that is frequently used to study brain activity when it is actively suppressing a specific behavior, also called inhibition. In this study, the authors asked research participants to sit in front of a computer while simple shapes appeared on screen, and they were to press a key when the shape was white—the most common-colored shape in the task—but not when purple, the least frequent color in the task. In other words, they responded to some stimuli (go) and inhibited their response to others (nogo). This is a similar task to playing music or speaking a second language because the brain has to identify relevant external sensory information, call on a set of learned rules about that information, and make a choice about what action to take.

 waves

The authors combined and compared correct responses to each stimulus type in control (non-musician, non-bilingual) groups, musician groups, and bilingual groups. The figure above compares the brainwaves of different groups over time using stimulus related brainwave components called N2, P2, and LP. As can be seen above, these peaks and valleys were significantly different between the groups in the nogo instances. The N2 wave is associated with the brain’s initial recognition of the meaning or significance of the stimulus and was strongest in the bilingual group. The P2 on the other hand, is associated with the early stages of putting a stimulus into a meaningful context as it relates to an associated behavior, and was strongest in the musician group. Finally, the authors note a wave called LP wave, which showed a prolonged monitoring response in the bilingual group. The authors believe this may mean bilinguals take more time to make sure their initial reaction is correct.

In other words, given a task that involved identifying a specific target and subsequently responding or not responding based on learned rules, these results suggest that musicians’ brains may be better at quickly assigning context and an appropriate response to information because they have a lot of practice turning visual and auditory stimuli into motor responses. Bilinguals, on the other hand, show a strong activation response to stimuli along with prolonged regulation of competing behaviors, likely because of their experience with suppressing the less relevant language in any given situation. Therefore, despite both musicianship and bilingual experiences improving brain function relative to controls, the aspects of brain function they improve are different. As games and activities for the purpose of “brain training” become popular, the researchers hope this work will help with testing the effectiveness of brain training.

Citation: Moreno S, Wodniecka Z, Tays W, Alain C, Bialystok E (2014) Inhibitory Control in Bilinguals and Musicians: Event Related Potential (ERP) Evidence for Experience-Specific Effects. PLoS ONE 9(4): e94169. doi:10.1371/journal.pone.0094169 

Images are Figures 1 and 2 from the article.

Category: Aggregators, Fun, General, Images, Topic Focus, Worth A Thousand Words | Tagged , , , , , , , , , , | Leave a comment

Signs of Change: Regional and Generational Variants in British Sign Language

British Sign Language chart

British Sign Language chart

As societies change, so too do its languages. In the English-speaking world, we often make note of changes in language by recognizing the rise of new words, like “selfie,” and the repurposing of familiar words, such as “because.” It may not be a surprise, then, to learn that this “evolution” isn’t limited to the spoken word: sign languages can also change over time. In a recent PLOS ONE study, scientists examined regional variations within British Sign Language (BSL), and found evidence that the language is evolving and moving away from regional variation.

To assist in this undertaking, the authors used data collected and recorded for the British Sign Language Corpus Project. About 250 participants took part in the project, recruited from eight regions in the UK. In addition to hailing from different parts of the country, participants came from various social, familial, and educational backgrounds.

When the first deaf schools were established across the UK in 1760, there was little standardization in signing conventions. Consequently, depending on the school you were attending, schools sometimes taught pupils to use different signs to convey the same concepts or words. The authors posit that this lack of standardization may be the basis for today’s regionalism in BSL.

The participants were given visual stimuli, such as colors or numbers, and then asked to provide the corresponding sign, one that they would normally use in conversation. The researchers also recorded participants engaging in unscripted conversations, a more formal interview, and in the delivery of a personal narrative, all of which were incorporated into the authors’ study and analyzed.

Example of the stimuli shown to participants.

Example of the stimuli shown to participants.

In their analysis, researchers focused on four concepts: UK place names, numbers, colors, and countries. The participants’ responses to the visual stimuli were compared to with their recorded conversation to control for any confounding variables, or unforeseen social pressure to sign in a particular way. The responses were also coded as being either “traditional” or “non-traditional” according to the regional signing conventions.

Results indicated that age may play a role in whether a participant uses traditional or non-traditional signs. Particularly when signing for countries, about half the responses given by younger participants were non-traditional signs. In addition, some participants—young and old—explained that they changed the country sign they used as they grew older. The researchers posit that this may be due to changing definitions of political correctness, in which older, more traditional signs are now perceived to be politically incorrect.

The authors also found that age may also play an important role in the participant’s use of color and number signs. As was the case for signing countries, younger participants were more likely to use non-traditional signs, and older participants more likely to use traditional signs. The researchers noted that younger participants using signs non-traditional to their region seemed to be adopting signing conventions from southern parts of the country, such as London, or from multiple regions. In other cases, younger participants responded by signing the first letter of the word, such as ‘p’ for purple. The authors attribute this generational shift to the participants’ increased exposure to different signing conventions, ushered in by technological developments, such as the Internet, and increased opportunities for travel.

Changing social norms, technologies, and opportunities—these are no strangers to us by now. As the world changes, so too do the ways in which we communicate, verbally and physically.

 

Citation:Stamp R, Schembri A, Fenlon J, Rentelis R, Woll B, et al. (2014) Lexical Variation and Change in British Sign Language. PLoS ONE 9(4): e94053. doi:10.1371/journal.pone.0094053

Image 1: British Sign Language chart by Cowplopmorris, Wikimedia Commons

Image 2: Figure 3 from article

Category: Aggregators, Topic Focus | Tagged , , , , , , , | 2 Comments

Statistics Predicted a Healthier Medieval London Following the Black Death

Black_Death

The Black Death, a pandemic at its height in Europe during the mid-14th century, was a virulent killer. It was so effective that it wiped out approximately one third of Europe’s population. Recent studies have shown that the elderly and the sick were most susceptible. But was the Black Death a “smart” killer?

A recent PLOS ONE study indicates that the Black Death’s virulence might have affected genetic variation in the surviving human population by reducing frailty, resulting in less virulent subsequent outbreaks of the plague. By examining the differences in survival rates and mortality risks in both pre-Black Death and post-Black Death samples of a London population—in combination with other, extrinsic factors, like differences in diet between the two groups—the researcher found that in London, on average, people lived longer following the plague than they did before it, despite repeated plague outbreaks. In other words, in terms of genetic variation, the Black Death positively affected the health of the surviving population.

To uncover differences in the health of medieval Londoners, Dr. Sharon DeWitte of the University of South Carolina examined 464 pre-Black Death individuals from three cemeteries and 133 post-Black Death individuals from one. She chose a diverse range of samples for a comprehensive view of the population, including both the rich and the poor, and women and children, but targeted one geographic location: London.

The ages-at-death of the samples were determined by calculating best estimates—in statistics these are called point estimates—based on particular indicators of age found on the skeletons’ hip and skull bones. Individuals’ ages were then evaluated against those in the Anthropological Database of Odense University, a pre-existing database comprising the Smithsonian’s Terry Collection and prior age-at-death data from 17th-century Danish parish records.

After estimating how old these individuals were when they died and comparing the age indicators against the Odense reference tool, the author conducted statistical analyses on the data to examine what the ages-at-death could tell us about the proportion of pre- and post- Black Death medieval Londoners who lived to a ripe old age, as well as the likelihood of death.

Survivorship was estimated using the Kaplan-Meier Estimator, a function used to indicate a quantity based on known data; in this case the function evaluated how long people lived in a given time period (pre-Black Death or post-Black Death). The calculated differences were significant: In particular, the proportion of adults who lived beyond the age of 50 from the post-Black Death group was much greater than those from the pre-Black Death group.

Age-at-death Distributions

Age-at-death Distributions

In the pre-Black Death group, death was most likely to occur between the ages of 10 and 19, as seen above.

The Kaplan-Meier survival plot shows how the chances of survival, which decrease with age, differ for Pre-Black Death and Post-Black Death groups, as seen below.

Survival Functions

Survival Functions

As the survival plot indicates, post-Black Death Londoners lived longer than there Pre-Black Death predecessors.

Finally, Dr. DeWitte estimated the risk of mortality by applying the age data to the statistical model known as the Gompertz hazard, which shows the typical pattern of increased risk in mortality with age. She found that overall post-Black Death Londoners faced lower risks of mortality than their pre-Black Death counterparts.

To make long and complicated methodology short, these analyses indicate that post-Black Death Londoners appear to have lived longer than pre-Black Death Londoners. The author estimates that the general population of London enjoyed a period of about 200 years of improved survivorship, based on these results.

The virulent killer, the Black Death, may have helped select for a healthier London by influencing genetic variation, at least in the short term. However, to better understand the improved quality of life of post-Black Death London, the author suggests further study to disentangle two major factors: the selectivity of the Black Death, coupled with improvements in lifestyle for post-Black Death individuals. For example, the massive depopulation in Europe resulted in increased wages for workers and improvements to diet following the plague, which also likely improved health for medieval Londoners. By unraveling intrinsic, biological changes in genetic variation from outside extrinsic factors like improvements in diet, it may be possible to better understand the aftermath of one of the most devastating killers in infectious disease history.

The EveryONE blog has more on the medieval killer here.

Citation: DeWitte SN (2014) Mortality Risk and Survival in the Aftermath of the Medieval Black Death. PLoS ONE 9(5): e96513. doi:10.1371/journal.pone.0096513

Image 1: The Black Death from Simple Wikipedia

Image 2: pone.0096513

Image 3: pone.0096513

Category: Aggregators, Fun | Tagged , , , , | 3 Comments