Mind your busyness

Selected coverage: Smithsonian Magazine, The Independent, NPR, Huffington Post

Busy seniors have better cognitive function, shows study

Are you busy on an average day? Do you often have too many things to do to get them all done? Do you often have so many things to do that you go to bed later than your regular bedtime?

If you are over 50 and the answer to these questions is a weary yes, here is some good news: older adults with a busy daily lifestyle tend to do better on tests of cognitive function than their less busy peers, shows a new study in Frontiers in Aging Neuroscience. The research is part of the Dallas Lifespan Brain Study, one of the most comprehensive studies of age-related changes in cognition and brain function in healthy adults currently underway in the USA.

“We show that people who report greater levels of daily busyness tend to have better cognition, especially with regard to memory for recently learned information,” says Sara Festini, a postdoctoral researcher at the Center for Vital Longevity of the University of Texas at Dallas and lead author of the study.

“We were surprised at how little research there was on busyness, given that being too busy seems to be a fact of modern life for so many,” says Denise Park, University Distinguished Chair at the Center for Vital Longevity, Director of the Dallas Lifespan Brain Study.

The researchers surveyed 330 participants in the Dallas Lifespan Brain Study – healthy women and men between 50 and 89 from the Dallas/Fort Worth area, Texas, recruited through media advertisements and community notices– about their daily schedule. The participants also visited the Park Aging Mind laboratory at the Center for Vital Longevity, where they took part in a long series of neuropsychological tests to measure their cognitive performance.

The results show that at any age, and regardless of education, a busier lifestyle is associated with superior processing speed of the brain, working memory, reasoning, and vocabulary. Especially strong is the association between busyness and better episodic memory, the ability to remember specific events in the past.

Festini et al. warn that the present data do not allow the conclusion that being busy directly improves cognition. It is also possible that people with better cognitive function seek out a busier lifestyle, or that busyness and cognition reinforce each other, resulting in reciprocal strengthening. But one mediating factor accounting for the relationship might be new learning, propose the researchers. Busy people are likely to have more opportunities to learn as they are exposed to more information and encounter a wider range of situations in daily life. In turn, learning is known to stimulate cognition: for example, a recent study from the Center for Vital Longevity found that a sustained effort in learning difficult new skills, such as digital photography or quilting, boosts episodic memory.

“Living a busy lifestyle appears beneficial for mental function, although additional experimental work is needed to determine if manipulations of busyness have the same effect,” says Festini.

EurekAlert! PR: http://www.eurekalert.org/pub_releases/2016-05/f-myb051016.php

Study: http://journal.frontiersin.org/article/10.3389/fnagi.2016.00098/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.

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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

 

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

New fossils push the origin of flowering plants back by 100 million years to the early Triassic

Selected coverage: Science Magazine, Der Spiegel, BBC, NBC, Discovery News, The Independent

Drilling cores from Switzerland have revealed the oldest known fossils of the direct ancestors of flowering plants. These beautifully preserved 240-million-year-old pollen grains are evidence that flowering plants evolved 100 million years earlier than previously thought, according to a new study in the open-access journal Frontiers in Plant Science.

Flowering plants evolved from extinct plants related to conifers, ginkgos, cycads, and seed ferns. The oldest known fossils from flowering plants are pollen grains. These are small, robust and numerous and therefore fossilize more easily than leaves and flowers.

An uninterrupted sequence of fossilized pollen from flowers begins in the Early Cretaceous, approximately 140 million years ago, and it is generally assumed that flowering plants first evolved around that time. But the present study documents flowering plant-like pollen that is 100 million years older, implying that flowering plants may have originated in the Early Triassic (between 252 to 247 million years ago) or even earlier.

Many studies have tried to estimate the age of flowering plants from molecular data, but so far no consensus has been reached. Depending on dataset and method, these estimates range from the Triassic to the Cretaceous. Molecular estimates typically need to be “anchored” in fossil evidence, but extremely old fossils were not available for flowering plants. That is why the present finding of flower-like pollen from the Triassic is significant, according to the team of researchers who made the discovery.

Peter Hochuli and Susanne Feist-Burkhardt from the University of Zürich studied two drilling cores from Weiach and Leuggern, northern Switzerland, and found pollen grains that resemble fossil pollen from the earliest known flowering plants. With Confocal Laser Scanning Microscopy, they obtained high-resolution images across three dimensions of six different types of pollen.

In a previous study from 2004, Hochuli and Feist-Burkhardt documented different, but clearly related flowering-plant-like pollen from the Middle Triassic in cores from the Barents Sea, south of Spitsbergen. The samples from the present study were found 3000 km south of the previous site. The authors believe that even highly cautious scientists will now be convinced that flowering plants evolved long before the Cretaceous.

What might these primitive flowering plants have looked like? In the Middle Triassic, both the Barents Sea and Switzerland lay in the subtropics, but the area of Switzerland was much drier than the region of the Barents Sea. This implies that these plants occurred across a broad ecological range. The pollen’s structure suggests that the plants were pollinated by insects: most likely beetles, as bees would not evolve for another 100 million years.

EurekAlert! PR: http://www.eurekalert.org/pub_releases/2013-10/f-nfp092513.php

Study: http://journal.frontiersin.org/article/10.3389/fpls.2013.00344/full