Older adults who have difficulty identifying common odors may have a greater risk of developing problems with thinking, learning and memory, according to a report in the July issue of Archives of General Psychiatry.

Mild cognitive impairment—or a decline in thinking, learning and memory abilities—is increasingly recognized as a precursor to Alzheimer’s disease, according to background information in the article. Impairments in the ability to recognize odors have been associated with more rapid cognitive decline and also with the development transition from mild cognitive impairment to Alzheimer’s disease. However, little is known about factors that predict the development of mild cognitive impairment.

Cooperation in animals has long been a major focus in evolutionary biology. In particular, reciprocal altruism, where helpful acts are contingent upon the likelihood of getting help in return, is especially intriguing because it is open to cheaters.

In a new study published this week Claudia Rutte and Michael Taborsky demonstrate the first evidence for generalized reciprocal cooperation in non-humans. The authors show that rats who received help in the past were more likely to help another unknown partner.

Researchers at the University of Utah and elsewhere have developed a new way to predict when vegetation dries to the point it is most vulnerable to large-scale fires in the Santa Monica Mountains near Los Angeles. And this year’s forecast says the highest-risk fire period will begin July 13 – weeks earlier than usual.

Despite that, the new study also shows that unlike other areas of the western United States, global warming has not caused any apparent long-term trend toward early fire seasons in the Santa Monicas.

The scientists eventually hope to expand their unique fire-risk forecasting method to all of Southern California and beyond.

We’ve all wondered how a seemingly healthy person can actually be at high risk for heart disease or a heart attack. Now researchers have uncovered a new clue to this mystery. The culprit: myeloperoxidase (MPO), a protein secreted by white blood cells that both signals inflammation and releases a bleach-like substance that damages the cardiovascular system.

Although MPO is intended to kill harmful bacteria, it may instead inflame the body’s arteries and cripple protective substances in the blood, according to a study published in the Journal of the American College of Cardiology (JACC). As a result, long before conventional risk factors set off alarms, elevated MPO levels signal that harmful plaque has been building up.

How precise are tests used to diagnose learning disability, progressive brain disease or impairment from head injury?

Timothy Salthouse, PhD, a noted cognitive psychologist at the University of Virginia, has demonstrated that giving a test only once isn’t enough to get a clear picture of someone’s mental functioning. It appears that repeating tests over a short period may give a more accurate range of scores, improving diagnostic workups.

Salthouse gave 16 common cognitive and neuropsychological tests to evenly divided participants (90 in the first, 1600 in the second) into groups of ages 18-39, 50-59 and 60-97 years old.

Psychologists from the University of Exeter have identified an 'early warning signal' in the brain that helps us avoid repeating previous mistakes. Published in the Journal of Cognitive Neuroscience, their research identifies, for the first time, a mechanism in the brain that reacts in just 0.1 seconds to things that have resulted in us making errors in the past.

Previous research has shown that we learn more about things for which we initially make incorrect predictions than for things for which our initial predictions are correct. The element of surprise in discovering we are wrong is conducive to learning, but this research is the first to show how amazingly rapid our brain’s response can be.