Study supports link between stress, epileptic seizures

Scientists have long thought that stress plays a role in epileptic seizures, and new evidence suggests that epilepsy patients who believe this is the case experience a different brain response when faced with a nerve-wracking situation.

Researchers from the University of Cincinnati performed functional MRI brain scans during a stressful math exercise on 16 epilepsy patients who pegged stress as a factor in their seizure control and seven patients who did not. While both groups performed similarly on the test, those who perceived stress to have an impact on their epilepsy showed greater brain activation than the others during intimidating parts of the test.

"One of the things we often hear is that a lot of epilepsy patients feel their seizures are affected by stress … but no one had really looked at their [brain response] or other elements of their physiological response," said study author Jane Allendorfer, an instructor of neurology at the University of Alabama at Birmingham. Allendorfer worked at University of Cincinnati while the study was conducted.

"We were a bit surprised to see this difference," she added, "but really excited to see it as well because this is something that hadn’t been done before."

The research was scheduled to be presented Monday at the annual meeting of the American Epilepsy Society, in San Diego. Data presented at scientific conferences often has not been peer-reviewed or published and is considered preliminary.

A brain disorder producing repeated seizures, epilepsy affects more than 2 million people in the United States, according to the U.S. Centers for Disease Control and Prevention. An estimated 50 million to 65 million people are affected by the condition worldwide.

New Research on How the Brain Makes Decisions

Neuroscience researchers at Trinity College Dublin have opened a new avenue for research on how the brain enables us to make decisions about our environment. By observing the gradual formation of a decision in brain activity before the particular decision was actually reported, the findings also have the potential to contribute to improved understanding and diagnosis of numerous brain disorders that are associated with impaired perceptual decision making. The discovery was recently published in Nature Neuroscience.

When interacting with our environment, we need to be sure about what we’re seeing, feeling or hearing in order to decide how to act. What does that road sign ahead say? Is that a train I hear approaching? Is it too dark for me to cycle home without a light? Somehow the brain enables us to make concrete decisions about the vast and often unreliable array of information it continually receives through the senses. One influential theory about how this might be achieved proposes that the brain allows information from the senses to accumulate over time and only commits to a particular decision once a reliable quantity has been gathered. While this theory has existed for several decades Assistant Professor, Redmond O’Connell at the Trinity College Institute of Neuroscience and colleagues are the first to have identified exactly how this occurs in the human brain.

The researchers designed a new test which required participants to detect a gradual change in a visual display or an auditory tone. The gradual change occurred over several seconds and was undetectable at first but eventually became obvious. This allowed the researchers to pinpoint the precise moment at which participants decided that a change had occurred. At the same time, the researchers recorded brain activity using electrodes placed on the scalp. Using this method the authors succeeded in isolating a brain signal that increased in parallel with the visual or auditory change and continued to increase thereafter. Most importantly, the authors found that participants only reported perceiving the change once this signal had reached a certain level. As a result, it was possible to precisely predict both the timing and accuracy of the participant’s decisions simply by monitoring this brain signal. In other words, it was possible to observe the gradual formation of a decision in the participant’s brain activity before that decision was actually reported.

Iron deficiency and cognitive development: New insights from piglets

University of Illinois researchers have developed a model that uses neonatal piglets for studying infant brain development and its effect on learning and memory. To determine if the model is nutrient-sensitive, they have done some research on the effects of iron-deficient diets.

“Iron deficiency is a major problem worldwide,” said Rodney Johnson, professor of animal sciences and director of the Division of Nutritional Sciences. “Infants who experience iron deficiency during the first 6 to 12 months of age can have irreversible developmental delays in cognition.”

He said that, even in the United States, iron deficiency is a significant problem. “Babies born to obese mothers are at risk for iron deficiency,” said Johnson. “Furthermore, the incidence of child obesity is increasing, and being overweight or obese is a risk factor for iron deficiency. Overweight toddlers are nearly three times more likely to suffer from iron deficiency than are those with a healthy weight.”

Johnson said that this work highlights a new translational model for studying micronutrient deficiencies. Traditional rodent models are less suited for examining these kinds of questions because they cannot be weaned early and placed on experimental diets. Pigs, however, are a precocial species, which means that their motor and sensory skills are quite well developed at birth. This facilitates early weaning and behavioral testing.

An article describing this research, “Early Life Iron Deficiency Impairs Spatial Cognition in Neonatal Piglets” by Jennifer L. Rytych, Monica R. P. Elmore, Michael D. Burton, Matthew S. Conrad, Sharon M. Donovan, Ryan N. Dilger, and Rodney W. Johnson has recently been published in The Journal of Nutrition.

First measurements made of key brain links

Until now, brain scientists have been almost completely in the dark about how most of the nonspecific thalamus interacts with the prefrontal cortex, a relationship believed to be key in such fundamental functions as maintaining consciousness and mental arousal. Brown University researchers performed a set of experiments, described in the Journal of Neuroscience, to explore and measure those circuits for the first time.

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Learning to control brain activity improves visual sensitivity

Researchers at the Wellcome Trust Centre for Neuroimaging at UCL used non-invasive, real-time brain imaging that enabled participants to watch their own brain activity on a screen, a technique known as neurofeedback. During the training phase, they were asked to try to increase activity in the area of the brain that processes visual information, the visual cortex, by imagining images and observing how their brains responded.

After the training phase, the participants’ visual perception was tested using a new task that required them to detect very subtle changes in the contrast of an image. When they were asked to repeat this task while clamping brain activity in the visual cortex at high levels, those who had successfully learned to control their brain activity could improve their ability to detect even very small changes in contrast.

This improved performance was only observed when participants were exercising control over their brain activity.

Lead author Dr Frank Scharnowski, who is now based at the University of Geneva, explains: “We’ve shown that we can train people to manipulate their own brain activity and improve their visual sensitivity, without surgery and without drugs.”

In the past, researchers have used recordings of electrical activity in the brain to train people on various tasks, including cutting their reaction times, altering their emotional responses and even improving their musical performance. In this study, the researchers used functional magnetic resonance imaging (fMRI) to provide the volunteers with real-time feedback on brain activity. The advantage of this technique is that you can see exactly where in the brain the training is having an effect, so you can target the training to particular brain areas that are responsible for specific tasks.

"The next step is to test this approach in the clinic to see whether we can offer any benefit to patients, for example to stroke patients who may have problems with perception, even though there is no damage to their vision," adds Dr Scharnowski.

Why Old People Get Scammed

Despite long experience with the ways of the world, older people are especially vulnerable to fraud. According to the Federal Trade Commission (FTC), up to 80% of scam victims are over 65. One explanation may lie in a brain region that serves as a built-in crook detector. Called the anterior insula, this structure—which fires up in response to the face of an unsavory character—is less active in older people, possibly making them less cagey than younger folks, a new study finds.

Both FTC and the Federal Bureau of Investigation have found that older people are easy marks due in part to their tendency to accentuate the positive. According to social neuroscientist Shelley Taylor of the University of California, Los Angeles, research backs up the idea that older people can put a positive spin on things—emotionally charged pictures, for example, and playing virtual games in which they risk the loss of money. “Older people are good at regulating their emotions, seeing things in a positive light, and not overreacting to everyday problems,” she says. But this trait may make them less wary.

To see if older people really are less able to spot a shyster, Taylor and colleagues showed photos of faces considered trustworthy, neutral, or untrustworthy to a group of 119 older adults (ages 55 to 84) and 24 younger adults (ages 20 to 42). Signs of untrustworthiness include averted eyes; an insincere smile that doesn’t reach the eyes; a smug, smirky mouth; and a backward tilt to the head. The participants were asked to rate each face on a scale from -3 (very untrustworthy) to 3 (very trustworthy).

In the study, appearing online in the Proceedings of the National Academy of Sciences, the “untrustworthy” faces were perceived as significantly more trustworthy by the older subjects than by the younger ones. The researchers then performed the same test on a different set of volunteers, this time imaging their brains during the process, to look for differences in brain activity between the age groups. In the younger subjects, when asked to judge whether the faces were trustworthy, the anterior insula became active; the activity increased at the sight of an untrustworthy face. The older people, however, showed little or no activation.

Scientists Discover Children’s Cells Living in Mothers’ Brains

The link between a mother and child is profound, and new research suggests a physical connection even deeper than anyone thought. The profound psychological and physical bonds shared by the mother and her child begin during gestation when the mother is everything for the developing fetus, supplying warmth and sustenance, while her heartbeat provides a soothing constant rhythm.

The physical connection between mother and fetus is provided by the placenta, an organ, built of cells from both the mother and fetus, which serves as a conduit for the exchange of nutrients, gasses, and wastes. Cells may migrate through the placenta between the mother and the fetus, taking up residence in many organs of the body including the lung, thyroid muscle, liver, heart, kidney and skin. These may have a broad range of impacts, from tissue repair and cancer prevention to sparking immune disorders.

It is remarkable that it is so common for cells from one individual to integrate into the tissues of another distinct person. We are accustomed to thinking of ourselves as singular autonomous individuals, and these foreign cells seem to belie that notion, and suggest that most people carry remnants of other individuals. As remarkable as this may be, stunning results from a new study show that cells from other individuals are also found in the brain. In this study, male cells were found in the brains of women and had been living there, in some cases, for several decades. What impact they may have had is now only a guess, but this study revealed that these cells were less common in the brains of women who had Alzheimer’s disease, suggesting they may be related to the health of the brain.

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