Neuroscience

Without sleep, the emotional centers of the brain dramatically overreact to negative experiences, reveals a new brain imaging study in Current Biology.   The reason for that hyperactive emotional response in sleep-deprived people stems from a shutdown of the prefrontal lobe—a region that normally keeps emotions under control. The new study from Harvard Medical School and the University of California, Berkeley is the first to explain, at the neural level, what seems to be a universal phenomenon: that sleep loss leads to emotionally irrational behavior, according to the researchers. The…

Height may point to a biological basis for pedophilia, according to new research released by the Centre for Addiction and Mental Health (CAMH). The study found that pedophilic males were shorter on average than males without a sexual attraction to children. The study, published in Sexual Abuse: A Journal of Research and Treatment, suggests that pedophiles may have been exposed to pre-birth conditions that affected their physical development. The researchers observed this height difference by analyzing the files of over 1,000 men who were assessed for pedophilia or other sexual disorders…

A five-minute eye exam might prove to be an inexpensive and effective way to gauge and track the debilitating neurological disease multiple sclerosis, potentially complementing costly magnetic resonance imaging to detect brain shrinkage - a characteristic of the disease’s progression. A Johns Hopkins-based study of a group of 40 multiple sclerosis (MS) patients used a process called optical coherence tomography (OCT) to scan the layers of nerve fibers of the retina in the back of the eye, which become the optic nerve. The process, which uses a desktop machine similar to a slit-lamp, is simple…

A research team combining high-energy physicists from the University of California, Santa Cruz, and neuroscientists from the Salk Institute in La Jolla, Calif., has discovered a type of retinal cell that may help monkeys, apes, and humans see motion. The cell type has very similar properties to so-called Y retinal ganglion cells, which were first described in cats in 1966. Upon the Y-cell's discovery, scientists began a decades-long search for its counterpart in primates. The UCSC–Salk Institute team named the new cell type the upsilon cell, after the Greek uppercase letter written as "Y."…

Although anorexia nervosa is categorized as an eating disorder, it is not known whether there are alterations of the portions of the brain that regulate appetite. Now, a new study finds that women with anorexia have distinct differences in the insulta – the specific part of the brain that is important for recognizing taste – according to a new study by University of Pittsburgh and University of California, San Diego researchers. The study also implies that there may be differences in the processing of information related to self-awareness in recovering anorexics compared to those without the…

A new study led by Kristin Kramer of the University of Memphis shows that manipulating oxytocin at birth can make changes in the central nervous system that only show up later in life. There's growing concern that the jolt of pitocin routinely used in U.S. hospital births could have unforeseen consequences. This study provides more ammunition. At the same time, it did not show that high doses of oxytocin interfere with social behavior later. The study, The organizational effects of oxytocin on the central expression of estrogen receptor alpha and oxytocin in adulthood, was published online…

The medical diagnosis of brain death is at odds with our traditional view of when death actually occurs, says Professor Allan Kellehear from the Centre for Death & Society at the University of Bath, speaking at an international conference on Death, dying & disposal. A diagnosis of brain death uses factors like fixed and dilated pupils, lack of eye movement and absence of respiratory reflexes but the social understanding of death is that it occurs when the heart stops beating. This makes decisions that often follow brain death, such as organ removal and the cessation of life support,…

It's hardly surprising that clinically depressed people act differently than healthy people. Quantifying the difference, however, can be difficult. Now a collaboration of physicists and psychiatrists in Japan has found a way to clearly and objectively measure depression. The researchers outfitted both healthy control subjects and depressed patients with accelerometers to continuously measure their motions over 5-day periods. Although activity levels in all of the subjects followed power-law patterns (a type of distribution that often turns up in physics studies of natural systems) the…

Purging is often associated with bulimics, who eat large quantities of food and then vomit. A University of Iowa professor says that purging is its own disorder, distinct because it involves women who eat small quantities of food and then vomit, unlike bulimics who may instead fast or over-exercise after eating. "Purging disorder is new in the sense that it has not been officially recognized as a unique condition in the classification of eating disorders," said Pamela Keel, associate professor of psychology in the UI College of Liberal Arts and Sciences, "But it's not a new problem. Women…

According to a new study, visual information is processed on a daily schedule set within the eyes themselves rather than one dictated by the brain. The researchers found in mice that the eyes’ normal rhythmic response to light requires only that a molecular "clock" inside the retina go on ticking. The retina is a layer of nerve tissue covering the back of the eyeball, which is often likened to the film in a camera; without it, images can't be captured. The results offer the first glimpse into the physiological importance of circadian clocks found in organs throughout the body, said Charles…