Tag: Daily Mail

Mixing cannabis with tobacco increases dependence risk, suggests study

Selected coverage: The Guardian, Culture Magazine, Daily Mail

People who mix tobacco with cannabis are less motivated to seek help to quit

Tobacco and cannabis are two of the world’s most popular drugs, used respectively by 1 billion and 182 million people worldwide (World Health Organization; United Nations Office on Drugs and Crime). The adverse health effects of tobacco are well known. Short-term effects of cannabis are transient impairments in motor function and working memory, planning, and decision-making, while possible long-term health effects of heavy cannabis use include physical and psychological dependence, permanent reductions in cognitive performance, cardiovascular and respiratory diseases, and some cancers (WHO).

Many users mix cannabis with tobacco, not only to save money but also because tobacco can increase the efficiency of cannabis inhalation. But such mixing can increase the risk of dependence, suggests a new study in Frontiers in Psychiatry.

“Cannabis dependence and tobacco dependence manifest in similar ways, so it is often difficult to separate these out in people who use both drugs,” says lead author Chandni Hindocha, a doctoral student at the Clinical Psychopharmacology Unit of University College London. “Cannabis is less addictive than tobacco, but we show here that mixing tobacco with cannabis lowers the motivation to quit using these drugs.”

Together with collaborators from University College London, the University of Queensland, King’s College London, and the South London and the Maudsley NHS Trust, Hindocha analyzed responses from 33,687 cannabis users who participated in the 2014 Global Drug Survey, an anonymous online survey of drug use, conducted each year in partnership with international media such as Die Zeit, The Guardian, Libération, and the Huffington Post. Participants came from a total of 18 countries in Europe, North and South America, and Australasia. The new study is the first to survey the popularity of different methods of cannabis consumption – so-called routes of administration – around the world.

Routes of administration vary widely between countries, show Hindocha and colleagues. For example, tobacco routes for cannabis – for example in joints, blunts, or pipes — are much more popular in Europe than elsewhere. Depending on the country, between 77.2% and 90.9% of European cannabis users use tobacco routes, while only 51.6% of Australian and 20.7% of New Zealand cannabis users do. Tobacco routes are least popular in the Americas, used by only 16% of Canadian, 4.4% of US, 6.9% of Mexican, and 7.4% of Brazilian cannabis users. In contrast, the use of cannabis vaporizers, a strictly non-tobacco route, is quite common in Canada (13.2% of cannabis users) and the United States (11.2%), but rare everywhere else (0.2 to 5.8%).

Importantly, preferences for routes of administration strongly affected the motivation to quit and to seek professional help for doing so. In particular, cannabis users who favor non-tobacco routes had 61.5% higher odds of wanting professional help to use less cannabis, and 80.6% higher odds of wanting help to use less tobacco, than users who prefer tobacco routes. Similarly, cannabis users who prefer non-tobacco routes had 10.7% higher odds of wanting to use less tobacco, and 103.9% higher odds of actively planning to seek help to use less tobacco.

These results suggest that people who regularly mix tobacco with cannabis are more at risk of psychological dependence than people who use cannabis and tobacco separately, without mixing them.

“Our results highlight the importance of routes of administration when considering the health effects of cannabis and show that the co-administration of tobacco and cannabis is associated with decreased motivation to cease tobacco use, and to seek help for ceasing the use of tobacco and cannabis,” says Michael T. Lynskey, Professor of Addictions in the National Addictions Centre of the Institute of Psychiatry, Psychology & Neuroscience at King’s College London. “Given a changing legislative environment surrounding access to cannabis in many jurisdictions, increased research focus should be given to reducing the use of routes of administration that involve the co-administration of tobacco.”

Other results include:

  • Worldwide, the most popular tobacco route of administration for cannabis is the joint, preferred by 93.4% of users of tobacco routes.
  • Pipes are the most popular non-tobacco route, preferred by 11.7% of users of non-tobacco routes.
  • Non-inhaled routes, such as bucket bongs, hot knifes, or in food or drink, were uncommon in every country surveyed (2.4% of cannabis users worldwide).
  • Men are more likely (68.2% of surveyed male cannabis users) than women (63.8% of surveyed female cannabis users) to use tobacco routes.
  • Users of tobacco routes tend to be younger (mean 26.2 years) than users of non-tobacco routes (mean 30.8 years).
  • 16.3% of respondents had never tried smoking tobacco independently of cannabis.

EurekAlert! PR: http://www.eurekalert.org/pub_releases/2016-07/f-mcw070116.php

Study: http://journal.frontiersin.org/article/10.3389/fpsyt.2016.00104/full

 

Linguists discover the best word order for giving directions

Selected coverage: NY Times, Christian Science Monitor, The Telegraph, The Independent, Daily Mail

Good directions start — literally — with the most obvious

To give good directions, it is not enough to say the right things: saying them in the right order is also important, shows a study in Frontiers in Psychology. Sentences that start with a prominent landmark and end with the object of interest work better than sentences where this order is reversed. These results could have direct applications in the fields of artificial intelligence and human-computer interaction.

“Here we show for the first time that people are quicker to find a hard-to-see person in an image when the directions mention a prominent landmark first, as in ‘Next to the horse is the man in red’, rather than last, as in ‘The man in red is next to the horse’,” says Alasdair Clarke from the School of Psychology at the University of Aberdeen, the lead author of the study.

Clarke et al. asked volunteers to focus on a particular human figure within the visually cluttered cartoons of the ‘Where’s Wally?’ children’s books (called ‘Where’s Waldo?’ in the USA and Canada). The volunteers were then instructed to explain, in their own words, how to find that figure quickly — no trivial task, as each cartoon contained hundreds of items. As expected, the volunteers often opted to indicate the position of the human figure relative to a landmark object in the cartoon, such as a building.

fpsyg-06-01793-g001
Example of “Where’s Wally?” image used in the experiment

What was surprising, however, was that they tended to use a different word order depending on the visual properties of the landmark. Landmarks that stood out strongly from the background — as measured with imaging software — were statistically likely to be mentioned at the beginning of the sentence, while landmarks that stood out little were typically mentioned at its end. But if the target figure itself stood out strongly, most participants mentioned that first.

In a separate experiment, the researchers show that the most frequently used word order, ‘landmark first-target-second’, is also the most effective: people who heard descriptions with this order needed on average less time to find the human figure in the cartoon than people who heard descriptions with the reverse order.

These results suggest that people who give directions keep a mental record of which objects in an image are easy to see, prefer to use these as landmarks, and treat them differently than harder-to-see objects when planning the word order of descriptions. This strategy helps listeners to find the target quickly.

“Listeners start processing the directions before they’re finished, so it’s good to give them a head start by pointing them towards something they can find quickly, such as a landmark. But if the target your listener is looking for is itself easy to see, then you should just start your directions with that,” concludes co-author Micha Elsner, Assistant Professor at the Department of Linguistics, Ohio State University.

These results could help to develop computer algorithms for automatic direction-giving. “A long-term goal is to build a computer direction-giver that could automatically detect objects of interest in the scene and select the landmarks that would work best for human listeners,” says Clarke.

EurekAlert! PR: http://www.eurekalert.org/pub_releases/2015-12/f-ldt120315.php

Study: http://journal.frontiersin.org/article/10.3389/fpsyg.2015.01793/full

 

Scientists date the origin of the cacao tree to 10 million years ago

Selected coverage: Science Magazine, The Times Scotland, Daily Mail, Tech Times, Live Science,

With Shauna Hay, Royal Botanic Garden Edinburgh, UK

New research shows that cacao trees evolved around 10 million years ago, earlier than previously believed. Considerable genetic variation might remain to be discovered among wild cacao populations, which could be crossbred with cultivated cacao for greater resistance to disease and climate change.

Chocolate, produced from seeds of the cacao tree Theobroma cacao, is one of the most popular flavors in the world, with sales around 100$ billion dollars per year. Yet, as worldwide demand increases, there are fears the industry will fail to cope with growing public hunger for the product. The main problem, common to many crops, is the lack of genetic variation in cultivated cacao, which makes it vulnerable to pests and blights. Lack of genetic variation also puts cacao trees at risk from climate change, jeopardizing the long-term sustainability of the industry.

Now, however, new research suggests the cacao tree is much older than previously realised — and may have close relations capable of sustaining our sweet-toothed appetites.

“Studies of the evolutionary history of economically important groups are vital to develop agricultural industries, and demonstrate the importance of conserving biodiversity to contribute towards sustainable development. Here we show for the first time that the source of chocolate, Theobroma cacao, is remarkably old for an Amazonian plant species,” says Dr James Richardson, a tropical botanist at the Royal Botanic Garden Edinburgh, UK, and lead author of the study.

Together with researchers from the University of Rosario and the University of the Andes in Colombia, the University of Miami, USA, and the United States Department of Agriculture (USDA), Richardson found that Theobroma cacao is one of the oldest species in the genus Theobroma, having evolved around 10 million years ago. At the time, the Andes were not yet fully elevated, which explains why cacao trees today occur on both sides of the Andes.

The species’ early evolutionary origin is good news: it suggests that cacao has had enough time to diversify genetically, with each wild population adapting to its local habitat. Wild populations of cacao across the Americas may therefore be treasure troves of genetic variation, which could be bred into cultivated strains to make the latter more resistant to disease and climate change, and perhaps even create new flavors of chocolate.

“After ten million years of evolution we should not be surprised to see a large amount of variation within the species, some of which might exhibit novel flavours or forms that are resistant to diseases. These varieties may contribute towards improving a developing chocolate industry,” says James Richardson.

The researchers already plan to return to South America to sample all species related to cacao and investigate the characteristics of their native populations.

“We hope to highlight the importance of conserving biodiversity so that it can be used to augment and safeguard the agricultural sector. By understanding the diversification processes of chocolate and its relatives we can contribute to the development of the industry and demonstrate that this truly is the Age of Chocolate,” says coauthor Dr Santiago Madriñán of the University of the Andes in Bogotá, Colombia.

The study is published in the open-access journal Frontiers in Ecology and Evolution.

EurekAlert! PR: http://www.eurekalert.org/pub_releases/2015-11/f-sdt110515.php

Study: http://journal.frontiersin.org/article/10.3389/fevo.2015.00120/full

Unlike people, monkeys aren’t fooled by expensive brands

Selected coverage: Le Monde, Yale News, L’Obs, Yahoo, Discover Magazine, Sydney Morning Herald, Herald Scotland, Daily Mail, Tech Times

In at least one respect, Capuchin monkeys are smarter than humans — they don’t assume a higher price tag means better quality, according to a new Yale study appearing in the open-access journal Frontiers in Psychology.

People consistently tend to confuse the price of a good with its quality. For instance, one study showed that people think a wine labeled with an expensive price tag tastes better than the same wine labeled with a cheaper price tag. In other studies, people thought a painkiller worked better when they paid a higher price for it.

The Yale study shows that monkeys don’t buy that premise, although they share other irrational behaviors with their human relatives.

“We know that capuchin monkeys share a number of our own economic biases. Our previous work has shown that monkeys are loss-averse, irrational when it comes to dealing with risk, and even prone to rationalizing their own decisions, just like humans,” said Laurie Santos, a psychologist at Yale University and senior author of the study. “But this is one of the first domains we’ve tested in which monkeys show more rational behavior than humans do.”

Rhia Catapano, a former Yale undergraduate who ran the study as part of her senior honors thesis, along with Santos and colleagues designed a series of four experiments to test whether capuchins would prefer higher-priced but equivalent items. They taught monkeys to make choices in an experimental market and to buy novel foods at different prices. Control studies showed that monkeys understood the differences in price between the foods. But when the researchers tested whether monkeys preferred the taste of the higher-priced goods, they were surprised to find that the monkeys didn’t show the same bias as humans.

Santos and colleagues think that differences in the response of humans and capuchins could stem from the different experiences that monkeys and people have with markets and how they behave.

“For humans, higher price tags often signal that other people like a particular good.” Santos noted. “Our richer social experiences with markets might be the very thing that leads us — and not monkeys — astray in this case.”

EurekAlert! PR: http://www.eurekalert.org/pub_releases/2014-12/yu-upm120114.php

Study: http://journal.frontiersin.org/article/10.3389/fpsyg.2014.01330/full

Citizens help researchers to challenge scientific theory

Selected coverage: The Independent, Daily Mail

Science crowdsourcing was used to disprove a widely held theory that “supertasters” owe their special sensitivity to bitter tastes to an usually high density of taste buds on their tongue, according to a study published in the open-access journal Frontiers in Integrative Neuroscience.

Supertasters are people who can detect and are extremely sensitive to phenylthiocarbamide and propylthiouracil, two compounds related to the bitter molecules in certain foods such as broccoli and kale. Supertasting has been used to explain why some people don’t like spicy foods or “hoppy” beers, or why some kids are picky eaters.

The sensitivity to these bitter tastants is partly due to a variation in the taste receptor gene TAS2R38. But some scientists believe that the ability to supertaste is also boosted by a greater-than-average number of “papillae”, bumps on the tongue that contain taste buds. Nicole Garneau, Curator and Chair of the Department of Health Sciences, Denver Museum of Nature & Science, and colleagues tested if this is true.

“There is a long-held belief that if you stick out your tongue and look at the bumps on it, then you can predict how sensitive you are to strong tastes like bitterness in vegetables and strong sensations like spiciness,” says Garneau. “The commonly accepted theory has been that the more bumps you have, the more taste buds you have and therefore the more sensitive you are.”

Over 3000 visitors to the museum’s Genetics of Taste Lab volunteered to stick their tongue out so that their papillae could be counted and their sensitivity to phenylthiocarbamide and propylthiouracil measured. In total, 394 study subjects were included in the analysis. Cell swabs from volunteers were taken to determine their DNA sequence at TAS2R38. Results confirmed that certain variations in TAS2R38 make it more likely that somebody is sensitive to bitter, but also proved that the number of papillae on the tongue does not affect increased taste sensitivity.

“No matter how we looked at the data, we couldn’t replicate this long held assumption that a high number of papillae equals supertasting,” says Garneau.

The authors argue against the continued misuse of the term supertaster, and for the use of the more objective term hypergeusia – abnormally sensitized taste – to describe people who are sensitive to all tastes and sensations from food.
“What we know and understand about how our bodies work improves greatly when we challenge central dogmas of our knowledge. This is the nature of science itself,” adds Garneau. “As techniques improve, so too does our ability to do science, and we find that what we accepted as truth 20, 30, or 100 years ago gets replaced with better theories as we gather new data, which advances science. In this case, we’ve proven that with the ‘Denver Papillae Protocol’, our new method for objective analysis for papillae density, we were unable to replicate well-known studies about supertasting.”

What make this study unique is that most of the results were collected by citizen scientists including over 130 volunteers who had been specially trained by Garneau and her colleagues. The Genetics of Taste Lab is located in the heart of the museum, uniquely situated to attract volunteers and dedicated citizen scientists who conduct population-based research about human genetics, taste, and health.

EurekAlert! PR: http://www.eurekalert.org/pub_releases/2014-05/f-chr052314.php

Study: http://journal.frontiersin.org/article/10.3389/fnint.2014.00033/full

How similar are the gestures of apes and human infants? More than you might suspect

Selected coverage: Smithsonian Magazine, Der Spiegel, LA Times, Slate, NBC, Discovery News, Yahoo, The Telegraph, Daily Mail

With Gozde Zorlu (Frontiers); Stuart Wolpert, Kristen Gillespie & Patricia Greenfield (UCLA Media Relations) 

Psychologists who analyzed video of a female chimpanzee, a female bonobo and a female human infant in a study to compare different types of gestures at comparable stages of communicative development found remarkable similarities among the three species.

This is the first time such data have been used to compare the development of gestures across species. The chimpanzee and bonobo, formerly called the “pygmy chimpanzee,” are the two species most closely related to humans in the evolutionary tree.

“The similarity in the form and function of the gestures in a human infant, a baby chimpanzee and a baby bonobo was remarkable,” said Patricia Greenfield, a distinguished professor of psychology at UCLA and co-author of the study.

Gestures made by all three species included reaching, pointing with fingers or the head, and raising the arms to ask to be picked up. The researchers called “striking” the finding that the gestures of all three species were “predominantly communicative,” Greenfield said.

To be classified as communicative, a gesture had to include eye contact with the conversational partner, be accompanied by vocalization (non-speech sounds) or include a visible behavioral effort to elicit a response. The same standard was used for all three species. For all three, gestures were usually accompanied by one or more behavioral signs of an intention to communicate.

Charles Darwin showed in his 1872 book “The Expression of the Emotions in Man and Animals” that the same facial expressions and basic gestures occur in human populations worldwide, implying that these traits are innate. Greenfield and her colleagues have taken Darwin’s conclusions a step further, providing new evidence that the origins of language can be found in gestures and new insights into the co-evolution of gestures and speech.

The findings are published today in the open-access journal Frontiers in Psychology.

The apes included in the study were named Panpanzee, a female chimpanzee (Pan troglodytes), and Panbanisha, a female bonobo (Pan paniscus). They were raised together at the Language Research Center in Atlanta, which is co-directed by Sue Savage-Rumbaugh, a co-author of the study. There, the apes learned to communicate with caregivers using gestures, vocalizations and visual symbols (mainly geometric shapes) called lexigrams.

“Lexigrams were learned, as human language is, during meaningful social interactions, not from behavioral training,” said the study’s lead author, Kristen Gillespie-Lynch, an assistant professor of psychology at the City University of New York and a former UCLA graduate student in Greenfield’s laboratory.

The human girl grew up in her parents’ home, along with her older brother. Where the apes’ symbols were visual, the girl’s symbols took the form of spoken words. Video analysis for her began at 11 months of age and continued until she was 18 months old; video analysis for the two apes began at 12 months of age and continued until they were 26 months old. An hour of video was analyzed each month for the girl, the chimpanzee and the bonobo.

Overall, the findings support the “gestures first” theory of the evolution of language. During the first half of the study, communicating with gestures was dominant in all three species. During the second half, all three species increased their symbol production — words for the child and lexigrams for the apes.

“Gesture appeared to help all three species develop symbolic skills when they were raised in environments rich in language and communication,” said Gillespie-Lynch, who conducted the research while she was at UCLA. This pattern, she said, suggests that gesture plays a role in the evolution, as well as the development, of language.

At the beginning stage of communication development, gesture was the primary mode of communication for human infant, baby chimpanzee and baby bonobo. The child progressed much more rapidly in the development of symbols. Words began to dominate her communication in the second half of the study, while the two apes continued to rely predominantly on gesture.

“This was the first indication of a distinctive human pathway to language,” Greenfield said.

All three species increased their use of symbols, as opposed to gestures, as they grew older, but this change was far more pronounced for the human child. The child’s transition from gesture to symbol could be a developmental model of the evolutionary pathway to human language and thus evidence for the “gestural origins of human language,” Greenfield said.

While gesture may be the first step in language evolution, the psychologists also found evidence that the evolutionary pathway from gesture to human language included the “co-evolution of gestural and vocal communication.” Most of the child’s gestures were accompanied by vocalization (non-language sounds); the apes’ gestures rarely were.

“This finding suggests that the ability to combine gesture and vocalization may have been important for the evolution of language,” Greenfield said.

The researchers conclude that humans inherited a language of gestures and a latent capacity for learning symbolic language from the last ancestor we share with our chimpanzee and bonobo relatives — an ancestor that lived approximately 6 million years ago.

The evolution of human language built on capacities that were already present in the common ancestor of the three species, the psychologists report.

“Our cross-species comparison provides insights into the communicative potential of our common ancestor,” Gillespie-Lynch said.

The article is titled “A cross-species study of gesture and its role in symbolic development: implications for the gestural theory of language evolution.” Other co-authors were Yunping Feng and Heidi Lyn.

EurekAlert! PR: http://www.eurekalert.org/pub_releases/2013-06/uoc–hsa060313.php

Study: http://journal.frontiersin.org/article/10.3389/fpsyg.2013.00160/full