Cognitive Benefit of Lifelong Bilingualism

Jan. 5, 2013 — Seniors who have spoken two languages since childhood are faster than single-language speakers at switching from one task to another, according to a study published in the January 9 issue of The Journal of Neuroscience. Compared to their monolingual peers, lifelong bilinguals also show different patterns of brain activity when making the switch, the study found.


 

The findings suggest the value of regular stimulating mental activity across the lifetime. As people age, cognitive flexibility — the ability to adapt to unfamiliar or unexpected circumstances — and related “executive” functions decline. Recent studies suggest lifelong bilingualism may reduce this decline — a boost that may stem from the experience of constantly switching between languages. However, how brain activity differs between older bilinguals and monolinguals was previously unclear.

In the current study, Brian T. Gold, PhD, and colleagues at the University of Kentucky College of Medicine, used functional magnetic resonance imaging (fMRI) to compare the brain activity of healthy bilingual seniors (ages 60-68) with that of healthy monolingual seniors as they completed a task that tested their cognitive flexibility. The researchers found that both groups performed the task accurately. However, bilingual seniors were faster at completing the task than their monolingual peers despite expending less energy in the frontal cortex — an area known to be involved in task switching.

“This study provides some of the first evidence of an association between a particular cognitively stimulating activity — in this case, speaking multiple languages on a daily basis — and brain function,” said John L. Woodard, PhD, an aging expert from Wayne State University, who was not involved with the study. “The authors provide clear evidence of a different pattern of neural functioning in bilingual versus monolingual individuals.”

The researchers also measured the brain activity of younger bilingual and monolingual adults while they performed the cognitive flexibility task.

Overall, the young adults were faster than the seniors at performing the task. Being bilingual did not affect task performance or brain activity in the young participants. In contrast, older bilinguals performed the task faster than their monolingual peers and expended less energy in the frontal parts of their brain.

“This suggests that bilingual seniors use their brains more efficiently than monolingual seniors,” Gold said. “Together, these results suggest that lifelong bilingualism may exert its strongest benefits on the functioning of frontal brain regions in aging.”

This research was funded by the U.S. National Institutes of Health and the National Science Foundation.


Story Source:

The above story is reprinted from materials provided bySociety for Neuroscience (SfN).

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Society for Neuroscience (SfN) (2013, January 5). Cognitive benefit of lifelong bilingualism.ScienceDaily. Retrieved January 12, 2013, from http://www.sciencedaily.com/releases/2013/01/130108201519.htm
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Gene Variant Linked to Active Personality Traits Also Linked to Human Longevity

Jan. 3, 2013 — A variant of a gene associated with active personality traits in humans seems to also be involved with living a longer life, UC Irvine and other researchers have found.

A variant of a gene associated with active personality traits in humans seems to also be involved with living a longer life, UC Irvine and other researchers have found. (Credit: © Alex Koch / Fotolia)

This derivative of a dopamine-receptor gene — called the DRD4 7R allele — appears in significantly higher rates in people more than 90 years old and is linked to lifespan increases in mouse studies.

Robert Moyzis, professor of biological chemistry at UC Irvine, and Dr. Nora Volkow, a psychiatrist who conducts research at the Brookhaven National Laboratory and also directs the National Institute on Drug Abuse, led a research effort that included data from the UC Irvine-led 90+ Study in Laguna Woods, Calif. Results appear online in The Journal of Neuroscience.

The variant gene is part of the dopamine system, which facilitates the transmission of signals among neurons and plays a major role in the brain network responsible for attention and reward-driven learning. The DRD4 7R allele blunts dopamine signaling, which enhances individuals’ reactivity to their environment.

People who carry this variant gene, Moyzis said, seem to be more motivated to pursue social, intellectual and physical activities. The variant is also linked to attention-deficit/hyperactivity disorder and addictive and risky behaviors.

“While the genetic variant may not directly influence longevity,” Moyzis said, “it is associated with personality traits that have been shown to be important for living a longer, healthier life. It’s been well documented that the more you’re involved with social and physical activities, the more likely you’ll live longer. It could be as simple as that.”

Numerous studies — including a number from the 90+ Study — have confirmed that being active is important for successful aging, and it may deter the advancement of neurodegenerative diseases, such as Alzheimer’s.

Prior molecular evolutionary research led by Moyzis and Chuansheng Chen, UC Irvine professor of psychology & social behavior, indicated that this “longevity allele” was selected for during the nomadic out-of-Africa human exodus more than 30,000 years ago.

In the new study, the UC Irvine team analyzed genetic samples from 310 participants in the 90+ Study. This “oldest-old” population had a 66 percent increase in individuals carrying the variant relative to a control group of 2,902 people between the ages of 7 and 45. The presence of the variant also was strongly correlated with higher levels of physical activity.

Next, Volkow, neuroscientist Panayotis Thanos and their colleagues at the Brookhaven National Laboratory found that mice without the variant had a 7 percent to 9.7 percent decrease in lifespan compared with those possessing the gene, even when raised in an enriched environment.

While it’s evident that the variant can contribute to longevity, Moyzis said further studies must take place to identify any immediate clinical benefits from the research. “However, it is clear that individuals with this gene variant are already more likely to be responding to the well-known medical adage to get more physical activity,” he added.

First author Deborah Grady, Maria Corrada, Valentina Ciobanu, Alexandra Moyzis, Chuansheng Chen and Dr. Claudia Kawas of UC Irvine; Diana Shustarovich and Gene-Jack Wang of Brookhaven; David Grandy of Oregon Health & Science University; Marcelo Rubinstein of Argentina’s National Scientific & Technical Research Council; and Qi Dong of Beijing Normal University also contributed to the study, which was supported by the U.S. Department of Energy, the National Institute on Aging, and the National Institute on Alcohol Abuse & Alcoholism intramural program.

 

Story Source:

The above story is reprinted from materials provided byUniversity of California – Irvine.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:

  1. D. L. Grady, P. K. Thanos, M. M. Corrada, J. C. Barnett, V. Ciobanu, D. Shustarovich, A. Napoli, A. G. Moyzis, D. Grandy, M. Rubinstein, G.-J. Wang, C. H. Kawas, C. Chen, Q. Dong, E. Wang, N. D. Volkow, R. K. Moyzis. DRD4 Genotype Predicts Longevity in Mouse and Human.Journal of Neuroscience, 2013; 33 (1): 286 DOI:10.1523/JNEUROSCI.3515-12.2013
 

 

University of California – Irvine (2013, January 3). Gene variant linked to active personality traits also linked to human longevity.ScienceDaily. Retrieved January 9, 2013, from http://www.sciencedaily.com/releases/2013/01/130103151515.htm

It’s in Our Genes: Why Women Outlive Men

ScienceDaily (Aug. 2, 2012) — Scientists are beginning to understand one of life’s enduring mysteries — why women live, on average, longer than men.

Newborn baby boy and girl. Scientists are beginning to understand one of life’s enduring mysteries — why women live, on average, longer than men. (Credit: © Barbara Helgason / Fotolia)


Published August 2 in Current Biology, research led by Monash University, describes how mutations to the DNA of the mitochondria can account for differences in the life expectancy of males and females. Mitochondria, which exist in almost all animal cells, are vital for life because they convert our food into the energy that powers the body.

Dr Damian Dowling and PhD student, Florencia Camus, both from the Monash School of Biological Sciences, worked with Dr David Clancy from Lancaster University to uncover differences in longevity and biological aging across male and female fruit flies that carried mitochondria of different origins. They found that genetic variation across these mitochondria were reliable predictors of life expectancy in males, but not in females.

Dr Dowling said the results point to numerous mutations within mitochondrial DNA that affect how long males live, and the speed at which they age.

“Intriguingly, these same mutations have no effects on patterns of aging in females. They only affect males,” Dr Dowling said.

“All animals possess mitochondria, and the tendency for females to outlive males is common to many different species. Our results therefore suggest that the mitochondrial mutations we have uncovered will generally cause faster male aging across the animal kingdom.”

The researchers said these mutations can be entirely attributed to a quirk in the way that mitochondrial genes are passed down from parents to offspring.

“While children receive copies of most of their genes from both their mothers and fathers, they only receive mitochondrial genes from their mothers. This means that evolution’s quality control process, known as natural selection, only screens the quality of mitochondrial genes in mothers,” Dr Dowling said.

“If a mitochondrial mutation occurs that harms fathers, but has no effect on mothers, this mutation will slip through the gaze of natural selection, unnoticed. Over thousands of generations, many such mutations have accumulated that harm only males, while leaving females unscathed.”

The study builds on previous findings by Dr Dowling and his team that investigated the consequences of maternal inheritance of mitochondria in causing male infertility.

“Together, our research shows that the mitochondria are hotspots for mutations affecting male health. What we seek to do now is investigate the genetic mechanisms that males might arm themselves with to nullify the effects of these harmful mutations and remain healthy,” Dr Dowling said.

 

Link:

http://www.eurekalert.org/pub_releases/2012-08/mu-iio073012.php

Journal Reference:

  1. M. Florencia Camus, David J. Clancy, Damian K. Dowling. Mitochondria, Maternal Inheritance, and Male Aging. Current Biology, 2012; DOI: 10.1016/j.cub.2012.07.018

Citation:

Monash University (2012, August 2). It’s in our genes: Why women outlive men. ScienceDaily. Retrieved August 4, 2012, from http://www.sciencedaily.com­ /releases/2012/08/120802122503.htm

Cutting daily sitting time to under three hours might extend life by two years

ScienceDaily (July 9, 2012) — Restricting the amount of time spent seated every day to less than 3 hours might boost the life expectancy of US adults by an extra 2 years, indicates an analysis of published research in the online journal BMJ Open.


And cutting down TV viewing to less than 2 hours every day might extend life by almost 1.4 years, the findings suggest.

Several previous studies have linked extended periods spent sitting down and/or watching TV to poor health, such as diabetes and death from heart disease/stroke.

The researchers used data collected for the National Health and Nutrition Examination Survey (NHANES) for 2005/6 and 2009/10, to calculate the amount of time US adults spent watching TV and sitting down on a daily basis.

NHANES regularly surveys a large representative sample of the US population on various aspects of their health and lifestyle.

They trawled the research database MEDLINE, looking for published studies on sitting time and deaths from all causes, and pooled the different relative risk data from the five relevant studies, involving almost 167,000 adults. The database was then reanalysed, taking account of age and sex.

They combined these data and the NHANES figures to come up with a population attributable fraction (PAF) — an estimate of the theoretical effects of a risk factor at a population, rather than an individual level — to calculate the number of deaths associated with time spent sitting down.

The PAFs for deaths from all causes linked to sitting time and TV viewing were 27% and 19%, respectively.

The results of life table analyses indicates that cutting the amount of time spent sitting down every day to under three hours would add an extra two years to life expectancy.

Similarly, restricting time spent watching TV to under two hours daily would extend life expectancy by an extra 1.38 years.

The authors emphasise that their analysis assumes a causal association rather than proving that there is one. But they point to the evidence showing the detrimental effect of a sedentary lifestyle on health.

And they caution that their findings should not be interpreted as meaning that someone who leads a more sedentary lifestyle can expect to live two or 1.4 years less than someone who is more active.

“The results of this study indicate that extended sitting time and TV viewing may have the potential to reduce life expectancy in the USA,” they write.

“Given that the results from objective monitoring of sedentary time in NHANES has indicated that adults spend an average of 55% of their day engaged in sedentary pursuits, a significant shift in behaviour change at the population level is required to make demonstrable improvements in life expectancy,” they conclude.

Further research will be required before recommendations on safe levels of sedentary behaviour can be made, they add.

BMJ-British Medical Journal (2012, July 9). Cutting daily sitting time to under three hours might extend life by two years. ScienceDaily. Retrieved July 11, 2012, from http://www.sciencedaily.com­ /releases/2012/07/120709231121.htm