Posts tagged science
Articles and news from the latest research reports.
For early man, walking beat talking
A new fossil discovery shows we did not climb out of the trees until much later than once thought.
To bee an art critic, choosing between Picasso and Monet
Honeybees are also discerning art critics, according to scientists from UQ’s Queensland Brain Institute, the UQ School of Psychology and the Federal University of Sao Carlos, Brazil.
The study, published in the Journal of Comparative Physiology A, found honeybees had remarkable visual learning and discrimination abilities that extended beyond simple colours, shapes or patterns.
QBI researcher Dr Judith Reinhard said honeybees had a highly developed capacity for processing complex visual information, and could distinguish landscape scenes, types of flowers, and even human faces.
“This suggests that in spite of their small brain, honeybees have a highly developed capacity for processing complex visual information, comparable in many respects to vertebrates,” she said.
Dr Reinhard and her team investigated whether this capacity extended to complex images that humans distinguish on the basis of artistic style, including Impressionist paintings by Monet and Cubist paintings by Picasso.
“We were able to show that honeybees learned to simultaneously discriminate between five different Monet and Picasso paintings, and that they did not rely on luminance, colour, or spatial frequency information,” she said.
When presented with novel paintings of the same style, the bees demonstrated an ability to generalise, suggesting they could differentiate Monet from Picasso by extracting and learning the characteristic visual information inherent in each style.
“Our study suggests that discrimination of artistic styles is not a higher cognitive function that is unique to humans, but simply due to the capacity of animals – from insects to humans – to extract and categorise the visual characteristics of complex images,” Dr Reinhard said.
Honeybees can bite as well as sting; venom could be anesthetic
Honeybees have defensive weapons at both ends of their bodies, Greek and French researchers have found: They can not only sting their enemies, as has long been known, but they can also bite them, injecting a venom that paralyzes invaders. The venom might be useful as an anesthetic in humans and other animals, the researchers speculate, and a British company has already patented the application and conducted preliminary tests suggesting that the venom works much like the well-known lidocaine.
The discovery was inadvertent. A team led by biologist Alexandros Papachristoforou of the Aristotle University of Thessaloniki in Greece was studying ways to control wax moths. The moths are a serious problem for beekeepers, invading hives, consuming wax and pollen and often destroying the honeycomb. Using natural products on the moths, the researchers tried 2-heptanone, which is produced naturally by the bees. At first, the team thought exposure to the chemical killed the wax moths. “However, on closer inspection, we realized that the wax moths were merely anesthetized for a period of one to nine minutes,” Papachristoforou said. “This was quite unexpected, so our scientific team set up a series of rigorous experiments to find out what was really happening and came up with our remarkable discovery.”
Their findings were published in the online journal Plos One.
Animals, including dogs, dolphins, monkeys and man, follow gaze. What mediates this bias towards the eyes? One hypothesis is that primates possess a distinct neural module that is uniquely tuned for the eyes of others. An alternative explanation is that configural face processing drives fixations to the middle of peoples’ faces, which is where the eyes happen to be located. We distinguish between these two accounts. Observers were presented with images of people, non-human creatures with eyes in the middle of their faces (`humanoids’) or creatures with eyes positioned elsewhere (`monsters’). There was a profound and significant bias towards looking early and often at the eyes of humans and humanoids and also, critically, at the eyes of monsters. These findings demonstrate that the eyes, and not the middle of the head, are being targeted by the oculomotor system.
How does the brain measure time?
(Image: bzztbomb)
Researchers at the University of Minnesota’s Center for Magnetic Resonance Research (CMRR) have found a small population of neurons that is involved in measuring time, which is a process that has traditionally been difficult to study in the lab.
In the study, which is published October 30 in the open access journal PLOS Biology, the researchers developed a task in which monkeys could only rely on their internal sense of the passage of time. Their task design eliminated all external cues which could have served as “clocks”.
The monkeys were trained to move their eyes consistently at regular time intervals without any external cues or immediate expectation of reward. Researchers found that despite the lack of sensory information, the monkeys were remarkably precise and consistent in their timed behaviors. This consistency could be explained by activity in a specific region of the brain called the lateral intraparietal area (LIP). Interestingly, the researchers found that LIP activity during their task was different from activity in previous studies that had failed to eliminate external cues or expectation of reward.
"In contrast to previous studies that observed a build-up of activity associated with the passage of time, we found that LIP activity decreased at a constant rate between timed movements," said lead researcher Geoffrey Ghose, Ph.D., associate professor of neuroscience at the University of Minnesota. "Importantly, the animals’ timing varied after these neurons were more, or less, active. It’s as if the activity of these neurons was serving as an internal hourglass."
By developing a model to help explain the differences in timing signals they see relative to previous studies, their study also suggests that there is no “central clock” in the brain that is relied upon for all tasks involving timing. Instead, it appears as though each of the brain’s circuits responsible for different actions are capable of independently producing an accurate timing signal.
One important direction for future research is to explore how such precise timing signals arise as a consequence of practice and learning, and whether, when the signals are altered, there are clear effects on behavior.
(Source: medicalxpress.com)
Empathy represses analytic thought, and vice versa
New research shows a simple reason why even the most intelligent, complex brains can be taken by a swindler’s story – one that upon a second look offers clues it was false.
When the brain fires up the network of neurons that allows us to empathize, it suppresses the network used for analysis, a pivotal study led by a Case Western Reserve University researcher shows.
How could a CEO be so blind to the public relations fiasco his cost-cutting decision has made?
When the analytic network is engaged, our ability to appreciate the human cost of our action is repressed.
At rest, our brains cycle between the social and analytical networks. But when presented with a task, healthy adults engage the appropriate neural pathway, the researchers found.
The study shows for the first time that we have a built-in neural constraint on our ability to be both empathetic and analytic at the same time
The work suggests that established theories about two competing networks within the brain must be revised. More, it provides insights into the operation of a healthy mind versus those of the mentally ill or developmentally disabled.
“This is the cognitive structure we’ve evolved,” said Anthony Jack, an assistant professor of cognitive science at Case Western Reserve and lead author of the new study. “Empathetic and analytic thinking are, at least to some extent, mutually exclusive in the brain.”
The research is published in the current online issue of NeuroImage.
Animals learn to fine-tune their sniffs
Animals use their noses to focus their sense of smell, much the same way that humans focus their eyes, new research at the University of Chicago shows.
A research team studying rats found that animals adjust their sense of smell through sniffing techniques that bring scents to receptors in different parts of the nose. The sniffing patterns changed according to what kind of substance the rats were attempting to detect.
The sense of smell is particularly important for many animals, as they need it to detect predators and to search out food. “Dogs, for instance, are quite dependent on their sense of smell,” said study author Leslie Kay, associate professor of psychology and director of the Institute for Mind & Biology at the University of Chicago. “But there are many chemicals in the smells they detect, so detecting the one that might be from a predator or an explosive, for instance, is a complex process.”
Kay was joined in writing the paper by Daniel Rojas-Líbano, a postdoctoral scholar at the University of Chile in Santiago, who received his PhD from UChicago in 2011. Rojas-Líbano, who did the work as a doctoral scholar, was the first author on the publication. Their results are published in an article, “Interplay Between Sniffing and Odorant Properties in the Rat,” in the current issue of the Journal of Neuroscience.
Unique protein bond enables learning and memory
Two proteins have a unique bond that enables brain receptors essential to learning and memory to not only get and stay where they’re needed, but to be hauled off when they aren’t, researchers say.
NMDA receptors increase the activity and communication of brain cells and are strategically placed, much like a welcome center, at the receiving end of the communication highway connecting two cells. They also are targets in brain-degenerating conditions such as Alzheimer’s and Parkinson’s.
In a true cradle-to-grave relationship, researchers have found the scaffolding protein, SAP102, which helps stabilize the receptor on the cell surface, binds with a subunit of the NMDA receptor called GluN2B at two sites, said Dr. Bo-Shiun Chen, neuroscientist at the Medical College of Georgia at Georgia Health Sciences University.
While one binding site is the norm, these proteins have one that’s stronger than the other. When it’s time for the normal receptor turnover, the stronger bond releases and the lesser one shuttles the receptor inside the cell for degradation or recycling.
“One binding site is involved in stabilizing the receptor on the cell surface and the other is important in removing the receptor. We think it’s a paradigm shift; we’ve never thought about the same scaffolding protein having two roles,” said Chen, corresponding author of the study in the journal Cell Reports.