Posts tagged science
Articles and news from the latest research reports.
Brain study shows why some people are more in tune with what they want
Wellcome Trust researchers have discovered how the brain assesses confidence in its decisions. The findings explain why some people have better insight into their choices than others.
Throughout life, we’re constantly evaluating our options and making decisions based on the information we have available. How confident we are in those decisions has clear consequences. For example, investment bankers have to be confident that they’re making the right choice when deciding where to put their clients’ money.
Researchers at the Wellcome Trust Centre for Neuroimaging at UCL led by Professor Ray Dolan have pinpointed the specific areas of the brain that interact to compute both the value of the choices we have in front of us and our confidence in those choices, giving us the ability to know what we want.
The team used functional magnetic resonance imaging (fMRI) to measure activity in the brains of twenty hungry volunteers while they made choices between food items that they would later eat. To determine the subjective value of the snack options, the participants were asked to indicate how much they would be willing to pay for each snack. Then after making their choice, they were asked to report how confident they were that they had made the right decision and selected the best snack.
It has previously been shown that a region at the front of the brain, the ventromedial prefrontal cortex, is important for working out the value of decision options. The new findings reveal that the level of activity in this area is also linked to the level of confidence participants placed on choosing the best option. The study also shows that the interaction between this area of the brain and an adjacent area reflects participants’ ability to access and report their level of confidence in their choices.
Dr Steve Fleming, a Sir Henry Wellcome Postdoctoral Fellow now based at New York University, explains: “We found that people’s confidence varied from decision to decision. While we knew where to look for signals of value computation, it was very interesting to also observe neural signals of confidence in the same brain region.”
Dr Benedetto De Martino, a Sir Henry Wellcome Postdoctoral Fellow at UCL, added: “Overall, we think our results provide an initial account both of how people make choices, and also their insight into the decision process.”
(Source: eurekalert.org)
Bryan Saunders, a performance and visual artist, undertook a high profile experiment in creativity, starting several years ago whereby, according to the artist, he created a series of self-portraits, each one done under the influence of a different substance—pretty much an A to Z assortment, from prescription meds like Abilify and Xanax to crystal meth. Over the weeks he’d create amazing pieces, suffer mild brain damage and end up hospitalized—all for the sake of art and creation.
Left brain people: process info in a linear manner, identify important details, are analytical, move in a sequential order, and use logic to solve problems.
Right brain people: process info holistically, see end results with clarity, are creative, move randomly form task to task, and use intuition to solve problems.
Why the Left-Brain Right-Brain Myth Will Probably Never Die?
The Science of Storytelling: Why Telling a Story is the Most Powerful Way to Activate Our Brains
We all enjoy a good story, whether it’s a novel, a movie, or simply something one of our friends is explaining to us. But why do we feel so much more engaged when we hear a narrative about events?
It’s in fact quite simple. If we listen to a powerpoint presentation with boring bullet points, a certain part in the brain gets activated. Scientists call this Broca’s area and Wernicke’s area. Overall, it hits our language processing parts in the brain, where we decode words into meaning. And that’s it, nothing else happens.
When we are being told a story, things change dramatically. Not only are the language processing parts in our brain activated, but any other area in our brain that we would use when experiencing the events of the story are too.
Exoskeleton suit gives man chance to walk again
Cutting edge technology has a Darien man taking miraculous steps.
He was paralyzed after he was struck by a car while riding his bike, training for an ironman four years ago.
Mike Loura was beaming as he was walking and showcasing this amazing robotic exoskeleton technology. He was doing something he never imagined he’d be able to do again.
"Ever since the accident all the doctors said you’re never going to walk again," Loura said.
However, the husband and father of two girls is walking again. Thursday was day 15, the day Loura strapped on the wearable robot, a breakthrough technology, but it’s the first time he’s taking steps for others to see.
"Every time I take a step I kinda have to balance myself in a certain position for the machine to know that it’s ready to take the next step," said Loura.
"It has an exoskeleton system with battery powered motor that allows someone who can’t feel and can’t move," said Dr. David Rosenblum, "who’s paralyzed, the ability to go from sit to stand to actually taking steps."
Dr. Rosenblum is the medical director of Rehabilitation at Gaylord Specialty Healthcare, the only center in Connecticut to offer the Ekso Bionics’ Robotic Exoskeleton technology to patients with spinal chord injuries.
"We’re using it as a tool to work on balance to get someone up and moving," said Dr. Rosenblum. "From a wellness perspective to improve their quality of life."
Proving that robots aren’t just for people any longer, African grey parrot, Pepper, has learned to drive a robot that was specially designed for him. Pepper, whose wing feathers are clipped to preventing him from flying around his humans’ house and destroying their things, now manipulates the joystick on his riding robot to guide it to where ever he wishes to go.
This robotic “bird buggy” was the brainchild of his human companion, Andrew Gray, a 29-year-old electrical and computer engineering graduate student at the University of Florida.
Scientists Identify Two Genes Essential for Breathing
A team of researchers at the New York University’s Langone Medical Center has discovered that two genes, called Hoxa5 and Hoxc5, play a critical role in establishing the neuronal circuits required for breathing. The discovery could help advance treatments for spinal cord injuries and neurodegenerative diseases.
The three-year study published in the journal Nature Neuroscience identifies a molecular code that distinguishes a group of muscle-controlling nerve cells collectively known as the phrenic motor column (PMC).
“These cells lie about halfway up the back of the neck, just above the fourth cervical vertebra, and are probably the most important motor neurons in your body,” explained senior author Prof Jeremy Dasen of the Howard Hughes Medical Institute.
Harming the part of the spinal cord where the PMC resides can instantly shut down breathing. But relatively little is known about what distinguishes PMC neurons from neighboring neurons, and how PMC neurons develop and wire themselves to the diaphragm in the fetus. The PMC cells relay a constant flow of electrochemical signals down their bundled axons and onto the diaphragm muscles, allowing the lungs to expand and relax in the natural rhythm of breathing.
“We now have a set of molecular markers that distinguish those cells from other populations of motor neurons, so that we can study them in detail and look for ways to selectively enhance their survival,” Prof Dasen said.
Episodic Memory and Appetite Regulation in Humans
Psychological and neurobiological evidence implicates hippocampal-dependent memory processes in the control of hunger and food intake. In humans, these have been revealed in the hyperphagia that is associated with amnesia. However, it remains unclear whether ‘memory for recent eating’ plays a significant role in neurologically intact humans. In this study we isolated the extent to which memory for a recently consumed meal influences hunger and fullness over a three-hour period. Before lunch, half of our volunteers were shown 300 ml of soup and half were shown 500 ml. Orthogonal to this, half consumed 300 ml and half consumed 500 ml. This process yielded four separate groups (25 volunteers in each). Independent manipulation of the ‘actual’ and ‘perceived’ soup portion was achieved using a computer-controlled peristaltic pump. This was designed to either refill or draw soup from a soup bowl in a covert manner. Immediately after lunch, self-reported hunger was influenced by the actual and not the perceived amount of soup consumed. However, two and three hours after meal termination this pattern was reversed - hunger was predicted by the perceived amount and not the actual amount. Participants who thought they had consumed the larger 500-ml portion reported significantly less hunger. This was also associated with an increase in the ‘expected satiation’ of the soup 24-hours later. For the first time, this manipulation exposes the independent and important contribution of memory processes to satiety. Opportunities exist to capitalise on this finding to reduce energy intake in humans.
Study of link between night eating and the peculiar internal clock of fat cells
When researchers at the University of Pennsylvania messed with the internal clocks of mouse fat cells, a surprising thing happened.
The mice got fat.
Figuring out why led to more surprises. Mice usually eat at night, but the altered mice ate more of their food during the day. They got fat even though they ate the same number of calories as regular, nocturnal-feeding mice.
And when the researchers gave altered mice two of the key ingredients in fish oil, the animals didn’t get fat.
That’s a lot to digest, but it has potential implications for humans as we enter the season of stuffed refrigerators that beckon some to eat when they should be resting.
Rapid fragmentation of neuronal networks at the onset of propofol-induced unconsciousness
General anesthesia involves rapidly inducing a reversible coma by administering a large dose of a fast-acting drug, such as propofol. Previous research has demonstrated that propofol enhances inhibitory input to neurons throughout the spinal cord, brainstem, thalamus, and cortex. However, how these effects in single cells translate to larger-scale neural circuits and cause unconsciousness is not well understood. We recorded spiking activity from ensembles of single neurons and intracranial electrical activity during the induction of propofol general anesthesia in human subjects undergoing surgery. We found that loss of consciousness (LOC) corresponds to the abrupt onset of a slow cortical oscillation that marks a fragmentation of neuronal networks. These results identify the slow oscillation as a dramatic neural correlate of LOC and demonstrate that slow oscillation marks the transition into a brain state in which local neuronal networks are isolated, impairing both temporal and spatial communication throughout the cortex.