Posts tagged neuroscience
Articles and news from the latest research reports.
Delayed Development: 20-Somethings Blame the Brain
Recent research into how the brain develops suggests that people are better equipped to make major life decisions in their late 20s than earlier in the decade. The brain, once thought to be fully grown after puberty, is still evolving into its adult shape well into a person’s third decade, pruning away unused connections and strengthening those that remain, scientists say.
"Until very recently, we had to make some pretty important life decisions about education and career paths, who to marry and whether to go into the military at a time when parts of our brains weren’t optimal yet," says neuroscientist Jay Giedd at the National Institute of Mental Health, whose brain-imaging studies of thousands of young people have yielded many of the new insights. Postponing those decisions makes sense biologically, he says. "It’s a good thing that the 20s are becoming a time for self-discovery."
Such findings are part of a new wave of research into “emerging adulthood,” the years roughly from 18 to 29, which psychologists, sociologists and neuroscientists increasingly see as a distinct life stage. The gap between adolescence and full adulthood is becoming ever wider as more young people willingly or because of economic necessity prolong their education and postpone traditional adult responsibilities. As recently as the 1960s, the average age of first marriage for women in the U.S. was 20, and men 22. Today, the average is 26 for women and 28 for men.
Struggling to Reconcile Conflicting Beliefs? Listen to Some Mozart
Countless claims have been made regarding the music of Mozart. Studies have suggested it can relieve depression, decrease pain, and even spark an increase in certain types of intelligence. One recent paper found it even increased heart transplant survival in mice.
Two researchers have identified another benefit. They provide preliminary evidence that listening to Mozart can help us cope with cognitive dissonance—that intense feeling of discomfort that arises when we realize two of our core beliefs are at odds.
The ability to recognize and accept the unpleasant reality that our convictions sometimes conflict is a key sign of emotional maturity. Without it, our instinct is to devalue, or refuse to believe, the information that makes us uncomfortable.
One example: If climate change requires collective action, and your instinct is to prize individual liberty, you can quell any cognitive dissonance by simply refusing to believe global warming is real.
How Do Blind People Picture Reality?
Paul Gabias has never seen a table. He was born prematurely and went blind shortly thereafter, most likely because of overexposure to oxygen in his incubator. And yet, Gabias, 60, has no trouble perceiving the table next to him. “My image of the table is exactly the same as a table,” he said. “It has height, depth, width, texture; I can picture the whole thing all at once. It just has no color.”
If you have trouble constructing a mental picture of a table that has no color — not even black or white — that’s probably because you’re blinded by your ability to see. Sighted people visualize the surrounding world by detecting borders between areas rich in different wavelengths of light, which we see as different colors. Gabias, like many blind people, builds pictures using his sense of touch, and by listening to the echoes of clicks of his tongue and taps of his cane as these sounds bounce off objects in his surroundings, a technique called echolocation.
Artificial cornea gives the gift of vision
Blindness is often caused by corneal diseases. The established treatment is a corneal transplant, but in many cases this is not possible and donor corneas are often hard to come by. In the future, an artificial cornea could make up for this deficiency and save the vision of those affected.
“We are in the process of developing two different types of artificial corneas. One of them can be used as an alternative to a donor cornea in cases where the patient would not tolerate a donor cornea, let alone the issue of donor material shortage,” says IAP project manager Dr. Joachim Storsberg.
The scientist has considerable expertise in developing and testing of next-generation biomaterials. Between 2005 and 2009 he collaborated with interdisciplinary teams and private companies to successfully develop an artificial cornea specifically for patients whose cornea had become clouded – a condition that is extremely difficult to treat. Such patients are unable to accept a donor cornea either due to their illness or because they have already been through several unsuccessful transplantation attempts. Dr. Storsberg was awarded the Josef-von-Fraunhofer Prize 2010 for this achievement. “A great many patients suffering from a range of conditions will be able to benefit from our new implant, which we’ve named ArtCornea®. We have already registered ArtCornea® as a trademark,” reports Storsberg.
Whether you like someone can affect how your brain processes their actions, according to new research from the Brain and Creativity Institute at the USC Dornsife College of Letters, Arts and Sciences.
Most of the time, watching someone else move causes a “mirroring” effect — that is, the parts of our brains responsible for motor skills are activated by watching someone else in action.
But a study by USC researchers appearing in PLOS ONE shows that whether you like the person you’re watching can actually have an effect on brain activity related to motor actions and lead to “differential processing” — for example, thinking the person you dislike is moving more slowly than they actually are.
“We address the basic question of whether social factors influence our perception of simple actions,” said Lisa Aziz-Zadeh, assistant professor with the Brain and Creativity Institute and the Division of Occupational Science. “These results indicate that an abstract sense of group membership, and not only differences in physical appearance, can affect basic sensory-motor processing.”
New Diabetes Biomarkers Could Help Develop New Treatments
Researchers from the German Institute of Human Nutrition and the Max Delbrueck Center for Molecular Medicine recently revealed that they have been able to identify 14 new biomarkers for type 2 diabetes. The findings are important, as scientists believe that these biomarkers may be able to help in the development of new treatments to help prevent the disease. The scientists also believe that the results of the study will help them understand the various elements that contribute to the development of type 2 diabetes.
Film explores struggles with rare diseases
There may be only a few thousand people in the United States who suffer from Hermansky-Pudlak syndrome, a disease so rare that most doctors have never even heard of it, much less know how to treat it.
But this very unusual condition is the focus of a documentary airing on public television this weekend, made by two Stanford filmmakers who are trying to draw attention to the plight of patients who suffer from rare diseases.
The documentary “Rare” airs at 6 p.m. Sunday on KQED. For more information about the film, and to see a preview, go to www.rarefilm.org
‘Disgusted’ Rats Teaching Scientists About Nausea, Work May Lead to New Cancer Treatments
Nausea is a common and distressing side effect of many drugs and treatments. Unlike vomiting, nausea is not well understood, but new research by University of Guelph scientists may soon change that.
Guelph PhD student Katharine Tuerke, neuroscience researcher Cheryl Limebeer and Prof. Linda Parker in the Department of Psychology believe they’ve found the mechanism in the brain that is responsible for the sensation of nausea – with the help of some “disgusted” rats.
Their study was published this week in Journal of Neuroscience.
“Although everyone has experienced nausea at some point, its neurobiology is poorly understood due to a lack of animal models,” said Parker, who holds the Canada Research Chair in Behavioural Neuroscience.
“We know about vomiting. The vomiting reflex is very well characterized, but the experience of nausea is something that little is known about. How is it generated? Where is it generated?”
Although rats can’t vomit, they do display a disgust reaction called gaping when re-exposed to a taste that made them feel nauseous in the past. Therefore, these gaping reactions in rats provide a model to understand brain mechanisms that produce nausea in humans.
The Date of Interbreeding between Neandertals and Modern Humans
Comparisons of DNA sequences between Neandertals and present-day humans have shown that Neandertals share more genetic variants with non-Africans than with Africans. This could be due to interbreeding between Neandertals and modern humans when the two groups met subsequent to the emergence of modern humans outside Africa. However, it could also be due to population structure that antedates the origin of Neandertal ancestors in Africa. We measure the extent of linkage disequilibrium (LD) in the genomes of present-day Europeans and find that the last gene flow from Neandertals (or their relatives) into Europeans likely occurred 37,000–86,000 years before the present (BP), and most likely 47,000–65,000 years ago. This supports the recent interbreeding hypothesis and suggests that interbreeding may have occurred when modern humans carrying Upper Paleolithic technologies encountered Neandertals as they expanded out of Africa.
Morphine and cocaine affect reward sensation differently
A new study by scientists in the US has found that the opiate morphine and the stimulant cocaine act on the reward centers in the brain in different ways, contradicting previous theories that these types of drugs acted in the same way.
Morphine and cocaine both affect the flow of the neurotransmitter dopamine, which has been shown to be important in the feeling of reward. When a dopamine neuron is stimulated it releases dopamine, which is then taken up by neighboring cells. Any excess is reabsorbed into the original dopamine neuron by a process known as “reuptake.”
Cocaine is known to block reuptake, and the excess dopamine leads to an enhanced reward effect. Cocaine is also known to make the cells in the nucleus accumbens, which receives signals from the VTA, more sensitive to cocaine. It was already known a protein called brain-derived neurotrophic factor (BDNF) in the VTA region of the brain enhances the reward response to cocaine.
The new study shows that BDNF has the opposite effect when morphine is present, decreasing the reward response and the development of addiction rather than enhancing it. The researchers identified numerous genes regulated by BDNF and associated with its effects. They used genetic techniques to suppress BDNF, and then directly excited the neurons in the nucleus accumbens that normally receives transmitted impulses from the VTA.
They found that suppressing BDNF in the VTA allowed morphine to increase the excitability of dopamine neurons and hence enhance the reward. When they optically excited the dopamine terminals in the nucleus accumbens that normally receive the transmissions from the VTA, they also found a reversal in the normal effect of BDNF.