Brain & Behavior

Hikers may disturb breeding spotted owls

Imagine if people kept hiking through your baby’s room. That’s essentially what happens in some of the canyons where Mexican spotted owls breed, and a new study shows that hikers can disrupt the owls’ behavior in ways that might harm their young. “We suggest that restrictions on hiking intensity should be considered for canyons with high levels of human activity,” say Elliott Swarthout, who did this work while at the University of Arizona in Tucson and is now at the Cornell Laboratory of Ornithology in Ithaca, New York, and Robert Steidl of the University of Arizona in Tucson in the February issue of Conservation Biology.

Study is first to confirm link between exercise and changes in brain

Three key areas of the brain adversely affected by aging show the greatest benefit when a person stays physically fit. The proof, scientists say, is visible in the brain scans of 55 volunteers over age 55. The idea that fitness improves cognition in the aging is not new. Animal studies have found that aerobic exercise boosts cellular and molecular components of the brain, and exercise has improved problem-solving and other cognitive abilities in older people. A new study in the February issue of the Journal of Gerontology: Medical Sciences, however, is the first to show — using high-resolution magnetic resonance imaging — anatomical differences in gray and white matter between physically fit and less fit aging humans.

Abortion ‘informed consent’ should include physical, psychological effects

Before women undergo induced abortions, doctors should — as part of the informed consent process — offer them information about the subsequent small but apparently real increased risk of pre-term delivery and depression, researchers say. Clinicians also should mention the unproven possibility that their chance of developing breast cancer could climb slightly later in life. Those are conclusions a team of doctors reached after completing a review of the best studies of the long-term physical and psychological health effects of intentional abortions.

Vision researchers find that photon receptors pair up in neat rows

Using atomic-force microscopy, vision researchers have taken pictures of some of the eye’s photon receptors in their natural state, and have analyzed their packing arrangement. Their findings, published in the Jan. 9 issue of Nature, offer insight on how light signaling might be controlled in the retina’s outer edge. The retina receives light through rods and cones. Rods, which are most heavily concentrated on the retina’s outer edge, are sensitive to dim light and to movement, but not to color. Rods, like cones, face away from incoming light. Within rods, light causes a chemical reaction with rhodopsin. This begins a chain of stimulation along the visual pathway, which sends information to the brain for interpretation. The brain can detect one photon of light, the smallest unit of energy, when it is absorbed by a photoreceptor.

Advanced Imaging Shows Crescendo, Diminuendo of Brain Circuitry

Using newly developed imaging techniques, neuroscientists for the first time have “unfolded” the brain’s sea-horse-shaped hippocampus to reveal how dynamic activity within the brain structure’s complex architecture orchestrates memory formation. Details appear in the Jan. 24 edition of the peer-reviewed journal Science. The researchers used extremely high-resolution functional magnetic resonance imaging (fMRI) and software developed at UCLA’s Ahmanson-Lovelace Brain Mapping Center to study blood flow within the hippocampus as 10 human volunteers learned to associate names with faces.

Human Gene Affects Memory

NIH scientists have shown that a common gene variant influences memory for events in humans by altering a growth factor in the brain’s memory hub. On average, people with a particular version of the gene that codes for brain derived neurotrophic factor (BDNF) performed worse on tests of episodic memory ? tasks like recalling what happened yesterday. They also showed differences in activation of the hippocampus, a brain area known to mediate memory, and signs of decreased neuronal health and interconnections. These effects are likely traceable to limited movement and secretion of BDNF within cells, according to the study, which reveals how a gene affects the normal range of human memory, and confirms that BDNF affects human hippocampal function much as it does animals’.

Even minor oxygen deprivation at birth can harm later cognitive function

Birth is a time of peril for the human brain, especially in pre-term infants. For vulnerable “preemies,” biochemical signs of reduced blood oxygen levels (hypoxia) soon after birth are associated with lower IQs and language skills. In 2001, premature babies were 12 percent of U.S. births – the highest level in 20 years, due in part to more multiple pregnancies, induced labor, and older mothers. The January issue of Neuropsychology, published by the American Psychological Association (APA) reports on links among pre-term birth, risk for birth hypoxia and cognitive problems, and reveals how the risk threshold for brain damage in preterm babies could be lower than thought.

Monkeys Show Sophisticated Learning Abilities

Psychologists have found evidence that monkeys have sophisticated abilities to acquire and apply knowledge using some of the same strategies as do humans. Specifically, the researchers have discovered that rhesus monkeys can learn the correct order of arbitrary sets of images and can apply that knowledge to answer new questions about that order. Not only can the monkeys choose which image came first in the same list, but they can also compare the order of pictures that came from different lists, found the researchers. The scientists said they have not yet found the limits of the monkeys’ learning capacity.

Researchers find link between improved memory and the use of neurofeedback

The results announced in the International Journal of Psychophysiology this month show a link between neurofeedback training and improved memory in a 40 person trial. Dr David Vernon, from Imperial College London at the Charing Cross hospital says: “Previous research has indicated that neurofeedback can be used to help treat a number of conditions including Attention Deficit Hyperactivity Disorder, epilepsy and alcoholism by training particular aspects of brain activity, but this is the first time we have shown a link between the use of neurofeedback, and improvements in memory.” Neurofeedback is a learning procedure that has been involved in treatments enabling participants to normalize behaviour, stabilize mood and improve their cognitive performance. It works by allowing people to watch their brain activity, and through this, find a way to correct or improve it.

Pharmacy consultations cut death, hospitalization rates

Patients may be less likely to die or be hospitalized from drug-related complications if they talk to their pharmacists about their prescriptions, new research finds. Intensive pharmacy consultations for patients taking “high-risk” medications contributed to an 8 percent drop in the number of drug-related deaths over two years, compared to the death rate among similar patients who received minimal or no pharmacy consultations, according to the study.

Mouse model links alcohol intake to marijuana-like brain compounds

Brain molecules similar to the active compound in marijuana help to regulate alcohol consumption, according to new reports by scientists. In studies conducted with a strain of mice known to have a high preference for alcohol, the scientists found greatly reduced alcohol intake in mice specially bred to lack CB1, the brain receptor for innate marijuana-like substances known as endocannabinoids. The effect was age dependent, the Bethesda group found. The New York scientists showed that the endocannabinoid system activates a brain region known as the nucleus accumbens, which plays a major role in mediating the rewarding effects of alcohol.