Tony Delroy Stories links August 19

Large human brain evolved as a result of ‘sizing each other up’

Planning A businessHumans have evolved a disproportionately large brain as a result of sizing each other up in large cooperative social groups, researchers have proposed.

A team led by computer scientists at Cardiff University suggest that the challenge of judging a person’s relative standing and deciding whether or not to cooperate with them has promoted the rapid expansion of human brain size over the last 2 million years.

In a study published in Scientific Reports today, the team, which also includes leading evolutionary psychologist Professor Robin Dunbar from the University of Oxford, specifically found that evolution favours those who prefer to help out others who are at least as successful as themselves.

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No blue light, please, I’m tired — light color determines sleepiness versus arousal in mice

The color of light matters: blue light keeps mice awake longer, while green light puts them to sleep easily. CREDIT Flickr user Pilottage. License: https://creativecommons.org/licenses/by/2.0/

The color of light matters: blue light keeps mice awake longer, while green light puts them to sleep easily.
CREDIT: Flickr user Pilottage. License: https://creativecommons.org/licenses/by/2.0/

Light affects sleep. A study in mice published in Open Access journal PLOS Biology shows that the actual color of light matters; blue light keeps mice awake longer while green light puts them to sleep easily. An accompanying Primer provides accessible context information and discusses open questions and potential implications for “designing the lighting of the future”.

Light shining into our eyes not only mediates vision but also has critical non-image-forming functions such as the regulation of circadian rhythm, which affects sleep and other physiological processes. As humans, light generally keeps us awake, and dark makes us sleepy. For mice, which are mostly nocturnal, light is a sleep-inducer. Previous studies in mice and humans have shown that non-image-forming light perception occurs in specific photosensitive cells in the eye and involves a light sensor called melanopsin. Mice without melanopsin show a delay in their response to fall asleep when exposed to light, pointing to a critical role for melanopsin in sleep regulation.

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Heading for a fall

Watch Your StepThe link between overconfidence and poor decision making is under the spotlight in an international study by scientists from Monash University and the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig.

People vary widely in their awareness of what they do and don’t know, or metacognitive ability, and in general are too confident when evaluating their performance. This often leads to poor decision making with potentially disastrous consequences, according to the report’s authors.

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‘Chemtrails’ not real, say leading atmospheric science experts

This is a condensation trail, or contrail, left behind an aircraft. Courtesy of Mick West.

This is a condensation trail, or contrail, left behind an aircraft. Courtesy of Mick West.

Some groups and individuals erroneously believe that the long-lasting condensation trails, or contrails, left behind aircraft are evidence of a secret large-scale spraying program. They call these imagined features “chemtrails.” Adherents of this conspiracy theory sometimes attribute this alleged spraying to the government and sometimes to industry.

The authors of this study, including Carnegie’s Ken Caldeira, conducted a survey of the world’s leading atmospheric scientists, who categorically rejected the existence of a secret spraying program. The team’s findings, published by Environmental Research Letters, are based on a survey of two groups of experts: atmospheric chemists who specialize in condensation trails and geochemists working on atmospheric deposition of dust and pollution.

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Physicists confirm possible discovery of fifth force of nature

"If confirmed by further experiments, this discovery of a possible fifth force would completely change our understanding of the universe," says UCI professor of physics & astronomy Jonathan Feng, including what holds together galaxies such as this spiral one, called NGC 6814. CREDIT: ESA/Hubble & NASA; Acknowledgement: Judy Schmidt

“If confirmed by further experiments, this discovery of a possible fifth force would completely change our understanding of the universe,” says UCI professor of physics & astronomy Jonathan Feng, including what holds together galaxies such as this spiral one, called NGC 6814.
CREDIT: ESA/Hubble & NASA; Acknowledgement: Judy Schmidt

Recent findings indicating the possible discovery of a previously unknown subatomic particle may be evidence of a fifth fundamental force of nature, according to a paper published in the journal Physical Review Letters by theoretical physicists at the University of California, Irvine.

“If true, it’s revolutionary,” said Jonathan Feng, professor of physics & astronomy. “For decades, we’ve known of four fundamental forces: gravitation, electromagnetism, and the strong and weak nuclear forces. If confirmed by further experiments, this discovery of a possible fifth force would completely change our understanding of the universe, with consequences for the unification of forces and dark matter.”

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This is your brain on sentences

These brain maps show how accurately it was possible to predict neural activation patterns for new, previously unseen sentences, in different regions of the brain. The brighter the area, the higher the accuracy. The most accurate area, which can be seen as the bright yellow strip, is a region in the left side of the brain known as the Superior Temporal Sulcus. This region achieved statistically significant sentence predictions in 11 out of the 14 people whose brains were scanned. Although that was the most accurate region, several other regions, broadly distributed across the brain, also produced significantly accurate sentence predictions. CREDIT: Andrew Anderson/University of Rochester

These brain maps show how accurately it was possible to predict neural activation patterns for new, previously unseen sentences, in different regions of the brain. The brighter the area, the higher the accuracy. The most accurate area, which can be seen as the bright yellow strip, is a region in the left side of the brain known as the Superior Temporal Sulcus. This region achieved statistically significant sentence predictions in 11 out of the 14 people whose brains were scanned. Although that was the most accurate region, several other regions, broadly distributed across the brain, also produced significantly accurate sentence predictions.
CREDIT: Andrew Anderson/University of Rochester

Researchers at the University of Rochester have, for the first time, decoded and predicted the brain activity patterns of word meanings within sentences, and successfully predicted what the brain patterns would be for new sentences.

The study used functional magnetic resonance imaging (fMRI) to measure human brain activation. “Using fMRI data, we wanted to know if given a whole sentence, can we filter out what the brain’s representation of a word is–that is to say, can we break the sentence apart into its word components, then take the components and predict what they would look like in a new sentence,” said Andrew Anderson, a research fellow who led the study as a member of the lab of Rajeev Raizada, assistant professor of brain and cognitive sciences at Rochester.

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A dog’s dilemma: Do canines prefer praise or food?

Most of the dogs in the experiments preferred praise over food, or liked them both equally. Kady, a Labrador-golden retriever mix, was the top dog when it came to the strength of her preference for praise. CREDIT Photo by Gregory Berns, Emory University

Most of the dogs in the experiments preferred praise over food, or liked them both equally. Kady, a Labrador-golden retriever mix, was the top dog when it came to the strength of her preference for praise. Photo by Gregory Berns, Emory University

Given the choice, many dogs prefer praise from their owners over food, suggests a new study published in the journal Social, Cognitive and Affective Neuroscience.

The study is one of the first to combine brain-imaging data with behavioral experiments to explore canine reward preferences.

“We are trying to understand the basis of the dog-human bond and whether it’s mainly about food, or about the relationship itself,” says Gregory Berns, a neuroscientist at Emory University and lead author of the research. “Out of the 13 dogs that completed the study, we found that most of them either preferred praise from their owners over food, or they appeared to like both equally. Only two of the dogs were real chowhounds, showing a strong preference for the food.”

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Most adults know more than 42,000 words

wordsHow many words do we know? It turns out that even language experts and researchers have a tough time estimating this.

Armed with a new list of words and using the power of social media, a new study published in Frontiers in Psychology, has found that by the age of twenty, a native English speaking American knows 42 thousand dictionary words.

“Our research got a huge push when a television station in the Netherlands asked us to organize a nation-wide study on vocabulary knowledge,” states Professor Marc Brysbaert of Ghent University in Belgium and leader of this study. “The test we developed was featured on TV and, in the first weekend, over 300 thousand Dutch speakers had done it – it really went viral.”

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Using the outside world to save on brainpower

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This illustration depicts metacognitive evaluation of internal vs. external strategies. CREDIT: Evan F. Risko

Every day, we rely on our physical surroundings–friends, gadgets, and even hand gestures–to manage incoming information and retain it.

In a Review published August 16 in Trends in Cognitive Sciences, two researchers explain the myriad ways in which forms of assistance from gestures to GPS affect both what we know and what we think we know.

Evan F. Risko, a Canada Research chair in Cognitive Psychology at the University of Waterloo, and co-author Sam Gilbert, a Royal Society research fellow at University College London, call these behaviors “cognitive offloading”–physical actions that reduce the mental effort needed to perform a task. When required to remember an appointment, for example, people are faced with the choice of internally remembering it or “offloading” it, by writing it down in a calendar or setting a reminder with a smartphone. Similarly, your accountant may choose to use a calculator when going over your finances rather than mentally perform all of the necessary computations.

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