Saturday, September 29, 2007

Carbs Help You Think

Following a lower-calorie diet causes improvement in mood regardless of whether it is of the low-fat, high-carb variety or a diet with lower carbs and higher fat intake. But the diet that seems to improve your cognitive abilities is the one with higher carbohydrate intake.

Research done at the Commonwealth Scientific and Industrial Research Organization-Human Nutrition, in Adelaide, Australia, found that those eating a higher carb diet performed better on intelligence and reasoning tests.

The study done on overweight adults measured mood and cognitive abilities after they were put on either a high-carb, low-fat diet or a high-fat low carb diet. Mood improved with reduced body weight in both groups but the group eating more carbohydrates showed slight improvement in cognitive function.


Friday, September 28, 2007

Time of Day Influences Learning

Studies on mammals have suggested that their ability to learn varies with the time of day and that for humans, disruption of their biological clocks can hamper learning at particular times of the day. A study at Vanderbilt University has found that for cockroaches, their ability to learn and retain information peaks at night, and is much lessened in the morning hours.

The article, Cockroaches are morons in the morning, details experiments with teaching cockroaches to prefer the scent of peppermint by associating it with sugar water. Those that were trained at night retained this information for several days, as did those trained in the evening. But cockroaches trained in the morning were unable to form a memory.

“Studies like this suggest that time of day can have a profound impact, at least in certain situations. By studying the way the biological clock modulates learning and memory we may learn more about how these processes take place and what can influence them."

Thursday, September 27, 2007

Brain Network for Intelligence Identified

We all know intelligence is a function of the brain, but where in the brain is it found? Researchers looking for the seat of intelligence have discovered a pathway that information in the brain follows. Their Parieto-Frontal Integration Theory (P-FIT) identifies a brain network related to intelligence, one that primarily involves areas in the frontal and the parietal lobes.

The findings are the result of a review of 37 imaging studies related to intelligence by Richard Haier of the University of California, Irvine and Rex Jung of the University of New Mexico .

“Recent neuroscience studies suggest that intelligence is related to how well information travels throughout the brain,” said Haier, a professor of psychology in the School of Medicine and longtime human intelligence researcher. “Our review of imaging studies identifies the stations along the routes intelligent information processing takes. Once we know where the stations are, we can study how they relate to intelligence.”

The report includes peer commentary from 19 researchers and appears online in the journal Behavioral and Brain Sciences.

Wednesday, September 26, 2007

Teaching Old Dogs (and Humans) New Tricks

We have all heard the saying: "You can't teach an old dog new tricks". But according to a study at Oregon State University, researchers found that the addition of two supplements to an older dog's diet did increase his ability to learn new tasks, and they think they may have the same effect in humans.

The two supplements, acetyl-l-carnitine and alpha lipoic acide are antioxidants that are believed to play a role in slowing mitochondrial decay in the cell.

In the tests, one group of dogs was given the supplements and another were given a normal diet. After 15 weeks of training, 80% of the dogs receiving supplements were able to learn the new task while only 50% of those on normal diets succeeded.

The scientists suggested in the paper that long-term supplementation “may be effective in attenuating age-associated cognitive decline by slowing the rate of mitochondrial decay and cellular aging.” Enhancing the function of mitochondria - which provide almost all of a cell’s energy - could literally be providing animals with more “mental energy,” leading to improved memory and learning, the study indicated. The compounds may also cause increased synthesis of a neurotransmitter called acetylcholine.

The beneficial effects were seen within only days or weeks of being given the supplements.

Tuesday, September 25, 2007

Obesity in Old Age Does Not Cause Memory Problems

Obesity in middle age carries a health risk that includes a higher risk of diabetes, high blood pressure and heart disease. Past studies have also indicated that obesity in middle age increases a person's risk of developing dementia or Alzheimer's disease. But a six-year study of 3,885 people over the age of 65 found that obesity in old age was not a risk factor for Alzheimer's.

In fact, the results of this study agree with earlier studies that found a correlation between a low BMI (body mass index) and Alzheimer's.

"While past studies have found obesity in middle age increases a person's risk for dementia or Alzheimer's disease, our findings show obesity in old age has no effect on a person's memory. These findings are consistent with previous studies showing that weight loss or low BMI in old age may be a precursor of cognitive decline or Alzheimer's disease."

The study was supported by the National Institute on Aging and the National Institute of Environmental Health Science and published by the American Academy of Neurology.


Monday, September 24, 2007

Music Training Enhances Verbal Skills

Musical training may be more important than phonics in learning language and communication skills, says a Northwestern University study.

Studying music enhanced sound encoding mechanisms that are also relevant for speech. In the Northwestern Study, scalp electrodes worn by test subjects fed data on multi-sensory brain responses to a cellist playing and a person speaking.

“Audiovisual processing was much enhanced in musicians’ brains compared to non-musician counterparts, and musicians also were more sensitive to subtle changes in both speech and music sounds,” said Nina Kraus, Hugh Knowles Professor of Communication Sciences and Neurobiology and director of Northwestern’s Auditory Neuroscience Laboratory, where the work was performed. “Our study indicates that the high-level cognitive processing of music affects automatic processing that occurs early in the processing stream and fundamentally shapes sensory circuitry.”

Music Training Linked to Enhanced Verbal Skills

Sunday, September 23, 2007

Sound Space Region of Brain Mapped

Researchers at the Hebrew University of Jerusalem believe they have identified a region of the brain responsible for perceiving "sound space". "Sound space" refers to the location from which sounds originate, an ability the listener displays, even when concentrating on something else.

In tests, subjects watched a movie with the sound turned off or were give button-pushing tasks while wearing headphones. The subjects were instructed to ignore the sounds they were being played through the headphones and to concentrate on the other tasks. The headphones had the ability to present a large variety of sounds with accurate reproduction of sound location. During the test, the brains of the subjects were scanned with functional MRI.

The researchers found that the planum temporale, which was previously thought to be responsible for only intentional processing of information was activated when bursts of noise were played to the subjects in the test. The researchers concluded that the planum temporale was responsible for automatic and non-intentional processing of sound location as well as intentional processing.

Atrophy in Older Brains Decreases Inhibitions

Do changes in the brain as we age lead to more depression, racism and compulsive behaviors like gambling?

According to a study published in the October issue of Current Directions in Psychological Science, the atrophy in the frontal lobes of aging brains makes it more difficult to control unwanted thoughts and behaviours.

These inhibitory losses may also cause socially inappropriate behaviors, such as asking personal questions in a public setting. Although the older adults knew that to ask questions about private issues, like weight, family problems and such were socially inappropriate, they were more likely to break those social rules.