12.13.07
Posted in Biology at the University of Virginia, DeForest Mellon, The Oscar Show, University of Virginia, biology, brain, crustaceans, evolution, nervous system, neurophysiology, sensory inputs, visual processing at 11:37 am by Jacob Canon
Today’s show, from an article published on the Oscar web site written by Fariss Samarrai, we examine lobsters and other crustaceans. What most people think of as food, is being utilized by UVa biology professor DeForest Mellon in his research of how the brain detects, integrates and uses co-joined yet dissimilar sensory inputs.
Inside the brain of crayfish [5:33m]:
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Imagine you are on a voyage to the bottom of the sea, or simply looking along the bottom of a clear stream observing lobsters or crayfish waving their antennae. Looking closer, you see them feeling around with their legs and flicking their antennules — the small, paired sets of miniature feelers at the top of their heads between the long antennae. While the long antennae are used for getting a physical feel of an area, such as the contours of a crevice, the smaller antennules are there to both help the creature smell and also to sense motion in the water that could indicate the presence of food, a mate or danger. The legs also have receptors that detect chemical signatures, preferably those emanating from a nice hunk of dead fish.
“They constantly flick their antennules,” says DeForest Mellon, a University of Virginia biology professor, “it is doing two things that are processed simultaneously in the brain as he flicks: smelling the water, and also sensing motion in the water, which can indicate the presence of food or other things of interest.” Mellon said, “I’m interested in understanding how these senses are combined and interpreted in the brain of these animals. My question is how does the brain detect, integrate and use these co-joined but dissimilar sensory inputs?”
“We taste food by a combination of senses, taste, aroma, texture and how good that dish looks. This complex process of brain processing is not much different with crustaceans, though their brains are much simpler, which makes them a great study model,” Mellon says. Mellon and other neurophysiology researchers commonly use crustaceans to try to gain basic understanding of the nervous systems of creatures in general. Extrapolating what they find to gain a basic understanding of the much more complex human brain.
Mellon says, “due to the large-sized nerve cells of invertebrates, we can conveniently and practically examine these systems that are largely the same among all creatures, and antennule flicking can serve as a practical model that helps us understand how two or more senses work together in the brain.”
Mellon has been investigating sensory systems for half a century, since his grad school days at Johns Hopkins University. And he’s still learning. Recently Mellon perused the research in the field — his own and that of many other scientists — of the past 45 years or so and published a review of the literature in the August 2007 issue of The Biological Bulletin.
What he’s found is that there is still much to be understood. “It’s fertile ground for ongoing research,” he said. “The size of an area of the brain devoted to a particular sense gives us a good idea of how an animal perceives the world. About 40 percent of a crustacean’s brain is devoted to the sense of smell. This shows how important detecting odors are to the animal.” “Crayfish and lobsters are generally solitary creatures, inhabiting an aquatic environment that is often dark, and they need that highly acute sense of smell.”Humans, by contrast, have less than 1 percent by volume of the brain devoted to interpreting smells, but about 30 percent of the human brain is concerned with visual processing.
Mellon said, “I have always been fascinated by the diversity of animal types and their equally diverse behaviors. Both are genetically based. And through often very subtle adoption of genetic variations in different animals, evolution has arrived at different solutions to common survival problems. This behavioral diversity and the variants in nervous system organization account for why I remain fascinated with biology.”
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11.22.07
Posted in Jacob Canon, James Coan, MRI, Psychology, Relationships, The Oscar Show, University of Virginia, anxiety, brain, emotions, environmental conditions, happiness, hypothalamus, immune, nervous system, neurobiology, neurophysiology, physical health, physiology, sensory inputs, stress at 3:46 pm by Jacob Canon
How did you react the last time you had a fight with that significant someone in your life? With couples, the woman might apologize, or the man might make a joke or express understanding. By doing this, they subtly and briefly lighten the tension as they work their way through a disagreement.
Psychology Professor James Coan discovered a long time ago that by doing this, even when couples fight, they take care of each other. This interplay was significant when Coan designed a study exploring what happens in people’s brains when they behave emotionally or observe other people’s emotions. Coan said, “what we are learning is our emotions are more heavily involved in our day-to-day physical health than we previously thought.
How we deal with our relationships is closely tied to how long we live, how frequently we go to the doctor, how rapidly we recover from injury, how happy we tend to be in our lives.” With his colleagues, Hillary Schaefer and Richard J. Davidson from the University of Wisconsin, Coan sought to demonstrate the neurobiological basis of emotional expression and regulatory processes.
In the study, they used MRI technology to view these responses at the level of glucose metabolism and blood oxygenation in the brain. Because of the importance of emotional connectedness to the study, 16 happily married, heterosexual couples were recruited as test subjects. Wives were placed in the scanner so brain activity could be recorded as each was exposed to the anxiety-producing possibility of an electric shock to the ankle.
Researchers wanted to see what effect different types of emotional support would have in areas of the brain related to the body’s normal fight-or-flight stress response. Readings were taken when the woman was alone in facing this challenge, When a stranger, a male, was present to support her And when her husband offered support. Coan stated, “the scanning environment is pretty hostile to looking at interactions between people.” The MRI machine surrounds the subject’s body and restricts movement. The women weren’t even able to see the support person during the scanning process.
Having the man offer his hand for the woman to hold was about the only intervention possible in this setting. Not surprisingly, the results show there was a healthy reduction in the stress response when test subjects were supported. Stimulation in the regions of the brain that regulate physiological arousal and coordinate large muscles and joints was significantly decreased, no matter who was holding the woman’s hand. However, when it was her husband’s hand she was holding, the response was significantly greater.
Coan said, “When you’re holding a spouse’s hand, you get down-regulation in all of those same systems. But all the other systems that have to do with the conscious regulation of your emotions — having to pay attention to what’s happening with your body and having to become more vigilant for future dangers — all of these other systems come down as well. Your brain doesn’t work as hard when it’s your spouse. What surprised Coan and his colleagues most was the relaxation response demonstrated by what they called “super couples.” In those couples with exceptionally high-quality relationships, “Hand-holding had a significantly greater effect on soothing their brains.”
Tests showed differences involving two structures that were not affected at all in other test subjects. They observed evidence of reduced release of stress hormones by the hypothalamus. These hormones are responsible for inhibiting immune response and other activities that have critical implications for health and well-being.
Of greater interest was the reduction of activity in the right anterior insula. This brain structure modulates the amount of pain stimulus one experiences subjectively. Reduction of activity in this area means test subjects actually felt less pain when they held their husband’s hand.
So it can be said, having someone you love hold your hand really can take the hurt away.
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11.15.07
Posted in Buddhist, Elevation, Jacob Canon, Psychology, Relationships, Social Psychology, The Oscar Show, University of Virginia, anxiety, biology, brain, emotions, ethics, happiness, philosophy, physical health, positive psychology, stress at 10:24 am by Jacob Canon
When social psychologist University of Virginia in 1995, he prepared by reading Thomas Jefferson’s writings and making the requisite pilgrimage to Monticello. Little did he realize the impact this Jeffersonian indoctrination would have on his own research.
Haidt’s area of specialization is moral emotions, but before coming to U.Va., he focused his studies on cross-cultural experiences of disgust. He read ancient Buddhist texts and spent time in India, exploring how the beneficial biological aspects of disgust became codified as religious imperatives and keys to social order.
Then he came across Thomas Jefferson’s letter to Robert Skipwith, in which Jefferson describes how “witnessing acts of beauty and moral goodness — whether in literature or reality — swells the chest and inspires a desire to lead a better life.” Suddenly Haidt began thinking about the antithesis of disgust, the psychological effect of uplifting experiences, an emotion he termed “elevation.” Haidt said,“That letter fundamentally changed the course of my research.”
In a moment of zeitgeist, Haidt’s inquiry into elevation coincided with the burgeoning of the academic field, positive psychology, which studies how people find meaning and happiness in life. His research into what prompts elevation and the resulting physical and motivational effects won him psychology’s largest monetary award, the John Templeton Prize for Positive Psychology, in 2001.
While researching elevation, Haidt continued teaching a large undergraduate survey course introducing the study of psychology. In the classroom, he has found it useful to cite quotations and examples from ancient philosophy and world religion to make his points more memorable. Haidt’s colleague, psychology professor Gerald Clore stated, “This penchant for asking what it all means makes him very appealing as an undergraduate lecturer in Introductory Psychology.”
Having received several university and state awards for teaching, Haidt decided to apply his ancient wisdom approach to a study of happiness. Looking at the relationship between what religious and philosophical traditions say about fulfillment and what scientists have discovered about the biological processes involved in the brain’s response to stimuli, Haidt gleaned 10 psychological truths from ancient religious and philosophical texts, which he examines in the 10 chapters of his 2006 book, The Happiness Hypothesis: Finding Modern Truth in Ancient Wisdom.
Throughout the work, Haidt analogizes the conscious mind to a rider straddling the elephant of the unconscious mind, trying to guide the giant beast where the rider wants it to go. He cited numerous psychological experiments that demonstrate how at odds the conscious and unconscious minds often are, despite the conscious mind’s skill at rationalizing choices and behavior. His book suggests that by understanding ancient wisdom’s insights into our divided nature, we have a chance of establishing a more harmonious relationship between the conscious and unconscious, gently training our elephants to do as we wish.
Haidt, who has also established an accompanying website, Happinesshypothesis.com , said, “every good idea I’ve ever had in my life is in this book, the book is really a gateway to everything I want to work on for the rest of my life.” Although Haidt spent 2005-2006 at Princeton University as the Laurence S. Rockefeller Visiting Professor of Ethics at the Center for Human Values, his heart remains in Charlottesville. Haidt said,“it really was because of U.Va., because of Jefferson, that I came to study this completely neglected area of emotion.”
Haidt is currently studying the foundations of moral judgment in liberals and conservatives in order to understand how political appeals might be better crafted. In addition, he’s researching how the application of elevation can be used to increase trust in relationships, especially among married couples.
To learn more about his work and this area of study, visit www.happinesshypothesis.com.
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