02.06.08

Locked-In Syndrome

Posted in Cognitive Science, Jacob Canon, The Oscar Show, UVa College of Arts & Sciences, Uncategorized, University of Virginia, nuerology, physical health, physiology, sensory inputs, technology, visual processing at 12:06 pm by Jacob Canon

In today’s show, adapted from an article published on the Oscar web site written by Linda Kobert, we examine the work of Dennis Proffitt, Professor and Director of the Cognitive Science Program, whose research focuses on creating computer interfaces to help make life more bearable for patients with ALS and other diseases that are the cause of locked-in syndrome.

Up to now, the most iconic connection to Amyotrophic Lateral Sclerosis or Lou Gehrig’s disease, is the famous farewell in Yankee stadium By Mr. Gerhig. Forced to retire from baseball, the profession he loved and was best known for, he became the personification of this devastating disease.

In 2002, Peggy Chun, a popular artist was diagnosed with ALS. This debilitating neurological disorder progressively destroys a person’s motor neurons. As a victim of this incurable disease, Chun can feel, see, smell, taste, think and imagine, but she can no longer move in any way. She is, in the parlance of the medical profession, “locked-in.” ALS is the most frequent cause of locked-in syndrome, which begins with numbness in the extremities and progresses upward until all motor function disappears.

Usually the last thing you lose is eye movement,” says Dennis Proffitt, U.Va. cognitive psychologist and Commonwealth Professor of Psychology. “When you lose that, you are cognitively alert, you can think, you can feel, but you can’t move a thing. As a result, you can’t communicate in any way. It’s awful.”

Funded by the National Science Foundation, Proffitt, his colleagues at Georgia Tech and a company called Archinoetics in Hawaii are working to develop computer interfaces that may one day make life for locked-in patients more bearable.

Scientists know different parts of the brain are activated when a person performs different functions. For example, moving the left arm activates an area on the right side of the brain, the back of the brain is active with visual imagery and the frontal lobe is active when one tries to focus attention on something. Proffitt’s system simply detects whether or not a particular area of the brain is actively engaged at the time.

With this in mind, researchers are currently testing a technology that allows Chun and other locked-in patients to answer simple yes/no questions. An interface using functional near infrared imaging (fNIR) assesses activity in Broca’s area, a part of the brain where verbal working memory occurs. They strap a device, just above the left ear that projects a light beam through the skull measuring changes in blood volume and oxygenation when Broca’s area is engaged.

With the device in place, subjects are asked to count in their head when they want to activate the verbal working memory and initiate a “yes” response. When they want to say “no,” subjects think of clouds or rest or think “la la la.” It’s a process that most people can engage easily without having to spend a long time training to do it.

Proffitt said, “it was hard for us to think of something we could ask a person to do — something easy to control, something you can turn on and off — that we could measure in this way. What we came up with was sub-vocal speech … talking to yourself. You could be counting, or you could be reciting a poem. We couldn’t tell the difference. We have no idea what you’re doing. We just know the kind of thing you’re doing.”

He stresses, “It’s not reading your thoughts, we can’t do that.”

Proffitt admitted, “at this time the system is primitive, but it’s a start. Right now it’s an on/off switch. What we want to do is to get continuous control so the person is not just activating … Not just ‘yes’ or ‘no,’ but small to large, continuous control within some range. If we could achieve that in the next few years, that would be a huge improvement in what we will be able to do with the technology.”

For the half million people in the world with locked-in syndrome, having the ability to communicate, even in this primitive fashion, can make the difference between suffering in silence and a meaningful life.

But Peggy Chun isn’t waiting for the technology to evolve. This future icon of the human spirit refuses to be shut down. She uses the system now as a tool for creativity. With the sensor in place over her left ear, the artist activates Broca’s area to select shades from a palette that show up on a computer screen as horizontal gradations of color. She calls it “brain art,” and it may be simple, but it’s selling like hotcakes.

You’ve been listening to the Oscar Show, I’m Jacob Canon. Join us next week when our topic will be the research of Jared Harris, assistant professor at the University of Virginia’s Darden School of Business concerning business ethics and strategy, as he looks to answer the questions, “What motivates a company to cook the books? And, what happens to businesses that get caught committing financial fraud?”

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12.13.07

Inside the brain of crayfish

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.

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

Please Hold

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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