High level of evidence for cognitive training

A recently published report funded by the National Institutes of Health (NIH) reviews the extensive literature on cognitive decline and Alzheimer’s disease in search of factors that might delay or prevent these age-related conditions. Of all the factors reviewed, including diet and dietary supplements, physical exercise, social engagement, and other leisure activities, only cognitive training was found to have a high level of evidence for being associated with a decreased risk of cognitive decline. So, if you want to engage in activities that are known to be associated with a reduced risk of cognitive decline, this report says that cognitive training is the only thing that currently fits the bill.

The nearly 800-page manuscript was prepared by the Duke Evidence-based Practice Center for the Agency of Healthcare Research and Quality (AHRQ), a part of the U.S. Department of Health and Human Services. This exhaustive report was created to support the NIH State-of-the-Science Conference “Preventing Alzheimer’s Disease and Cognitive Decline.” The conference brought together health experts with specific expertise in aging and age-related changes in cognition to discuss the current state of knowledge related to treatments for age-related cognitive decline and Alzheimer’s disease. The report takes a very conservative approach to its evaluation of risk factors and potential treatments for age-related problems of cognition. In fact, only cognitive training was found to have a high degree of evidence for reducing the risk of age-related cognitive decline. Hundreds of studies were reviewed, and while many studies offered evidence that was suggestive of reducing risks, most were correlational, rather than experimental, in nature. For instance, some studies showed a relationship between eating a “Mediterranean diet” and reduced risk of cognitive decline. But these studies typically just ask people about their diet and correlate these factors to cognitive performance. Conversely, there have been several randomized, controlled trials that have shown improved cognitive performance through cognitive training. This higher degree of rigor earned cognitive training the “high degree of evidence” designation in this report.

Of course, that’s not to say you shouldn’t take care of yourself in other ways. Other factors such as a diet high in vegetables and omega-3 fatty acids, physical activity, and some leisure activities were found to be associated with a decreased risk of cognitive decline, albeit with a low level of evidence. In other words, these things are likely good for your brain, but the authors did not feel there was enough evidence to say so definitively. Given that most of these lifestyle factors are good for you in other ways, there’s certainly no harm in eating better, getting more exercise, or spending more time with friends and family. If you want to see how your lifestyle may be affecting your brain health, take our Brain Grade test.

This report is just another reason to make cognitive training — like Lumosity.com — a regular part of your brain health routine.

Even mice benefit from brain training!

Working memory training has been shown to be effective in improving fluid intelligence in humans. Now, research out of Rutgers has shown a similar effect in mice. This finding in mice reinforces the idea that brain enhancement through neuroplasticity is generally possible among mammals, and it opens up exciting possibilities for future research.

Researchers trained mice on a task that exercised working memory and attention, and measured their ability to perform a range of mentally challenging tasks before and after training. The mice that received focused brain training improved on measures of generalized cognitive function compared to control mice with no training. The researchers, who recently published this work in the prestigious journal Current Biology, imply that you can think of these tests as IQ tests for mice. In other words, working memory training seems to have actually made these mice smarter!

For training, the mice needed to simultaneously remember two maze configurations, and be able to make their way through either one. The mice then completed several tests to measure the effect of the training on their intelligence and ability to learn. The training made the mice better at tests that didn’t involve mazes at all, like learning how to avoid an unpleasant stimulus.

So, as in brain training studies in humans, the mice didn’t just get better at what they were practicing – they also became generally more intelligent. This transfer of training is the gold standard in assessing the effectiveness of brain training. Transfer implies that underlying brain systems are fundamentally changed by the learning, and it’s not just that the subject learned how to take the test.

This kind of transfer has been shown many times in human studies — including transfer from speed of processing training to driving ability, auditory processing training to memory performance, and working memory training to fluid intelligence — but, this is the first such result demonstrated in a non-human animal. This is significant for a few reasons. First of all, it implies that improvement in general cognitive function with brain training is a fundamental capacity of the mammalian brain, not just a human trait. Also, this paradigm allows for research that is difficult to perform on humans. The environment of mice can be very carefully controlled, eliminating many of the confounding variables inherent in research on humans. Researchers can breed mice to have certain characteristics and even knock out certain genes and replace them with others. This opens up the possibility of testing the effects of brain training on conditions like Alzheimer’s Disease, for which there are mouse models. Many new avenues of research are opened by the demonstration of this effect in mice.

This result represents an important milestone in study of brain training! It reinforces what we already know — the brain is highly adaptable and can be improved with training, and it gives us new avenues to explore. We’re looking forward to seeing what this team comes up with next.

Joe Hardy, PhD

Introducing Lumosity Brain Trainer for iPhone

Have you ever wanted to take the Lumosity experience with you everywhere you go? Now you can play your favorite Lumosity games and access your favorite parts of the program even when you are away from your computer. With Lumosity Brain Trainer, our 2 million members can now train their brain using their iPhone and iPod touch. For years, Lumosity has worked closely with the world’s leading neuroscientists from top universities — including Stanford, UCSF and Berkeley — to create the best cognitive enhancement program. This complete program is now available for the iPhone platform.

Free to download, Lumosity Brain Trainer includes 35 daily training sessions of 7 brain games designed to enhance your cognitive abilities, including memory, processing speed, attention, flexibility, and problem solving. Playing these brain games a few minutes every day will help achieve the best results.

Just like our online users, our iPhone users will experience the following benefits:

• Improved memory
• Enhanced mood
• Better problem solving skills
• Ability to think faster

Lumosity Brain Trainer also helps you track your progress in each cognitive function using the Brain Performance Index (BPI). By using Lumosity Brain Trainer, you should see your BPI improve overtime.

Existing Lumosity members can access Brain Trainer using their existing accounts and will see their performance reflected in their history and brain profile. New users who are starting with Brain Trainer will have a complete Lumosity experience on the iPhone and will also have the opportunity to further develop specific brain attributes through Lumosity.com.

Memory BPI in Lumosity Brain Trainer

Targeted Cognitive Exercises Improve Mental Abilities

Training with cognitive exercises can improve targeted mental functions, conclude the authors of a review article published recently in the journal Alzheimer’s and Dementia.  The authors (Kathryn Papp and Stephen Walsh from the University of Connecticut and Peter Snyder from Brown University) reviewed ten randomized controlled trials involving cognitive training interventions in healthy adults published since 1992.  They find that specific abilities such as memory, reasoning, and speed of processing can be improved through targeted training programs.  This is an important conclusion, and it is consistent with the growing evidence in support of the effectiveness of cognitive training.

The authors point out that the benefits of cognitive training tend to be specific to the trained domain.  So, if you want improved memory — train on games designed to improve memory.  If you want improved attention — train with attention games, and so on.  The relationship to physical exercise is apparent.  If you want big biceps — do curls.  If you want ripped abs — do sit ups.  Lumosity was designed with these principles in mind.  This is why the site contains over 30 games targeting cognitive functions spanning speed of processing, memory, attention, flexibility, and problem solving — a complete gym for the brain.

It is also clear from this review that there is still much to learn.  Few of the studies have follow-up testing longer than a few months, and many of them lack measures of real-world benefits such as activities of daily living.  However, where longer follow-ups and real-world benefits are measured, benefits are seen to be long lasting and quite general.  For example, in the ACTIVE study of cognitive training in normal healthy older adults, benefits to activities of daily living are seen 5 years after the training intervention ended.

While there is still much to learn, the weight of the evidence is showing that cognitive training can be highly effective when properly designed and executed.

Eating fish may reduce risk of stroke

By Gregory Kellett, a cognitive neuroscience researcher at SFSU and UCSF, and science writer for Lumos Labs.

Eating lots of fish, the ultimate brain food, was recently associated with reduced risk of stroke.

A study conducted by Jyrki Virtanen and his crew at the University of Kuopio in Finland found that people who ate more fish tended to have fewer strokes. Virtanen looked at a population of 2,313 participants over the age of 65 who had their brains scanned (via MRI) twice, with a 5-year lapse between scans. After analyzing answers the participants gave to diet-related questionnaires the researchers found that:

• Those eating fish 3 or more times a week had fewer sub-clinical infarcts or “mini-strokes” than those eating fish less than once a month.
• Consuming more fish was associated with more intact brain white matter.
• Fried fish is not so healthy, and seemed to negate the above benefits.

As seen in other research studying healthy brain food, omega-3 fatty acids, which are present in most fish oils, seem to be a key contributor to lowering the risk of stroke.

Reference: Virtanen, J. K., Siscovick, D. S., Longstreth, W. T., Kuller, L. H., & Mozaffarian, D. (2008). Fish consumption and risk of subclinical brain abnormalities on MRI in older adults. Neurology, 71(6), 439-446.

Brain Hydration

By Gregory Kellett, a cognitive neuroscience researcher at SFSU and UCSF, and science writer for Lumos Labs.

Your brain is made up of 60% water and many of us may not be drinking enough of the clear wet stuff to keep our thinking “juicy.”

Not drinking enough water has detrimental effects on our brains. When your body lacks water, brain cells and other neurons shrink and biochemical processes involved in cellular communication slow. A drop of as little as 1 to 2% of fluid levels can result in slower processing speeds, impaired short-term memory, tweaked visual tracking and deficits in attention.

With proper hydration however, neurons work best and are capable of reacting faster.

What constitutes proper hydration is controversial. Some say that it is important to imbibe 8 tall glasses of water daily, while others claim that one should only drink when thirsty.

In fact, there is no one golden rule to staying well hydrated. The amount of water each of us needs varies from person to person as it depends on each individual’s physiology and lifestyle activities like diet and exercise.

Experiment and see what feels good. In today’s world of infinite distractions however, it is best not to leave hydration to your sense of thirst alone. It is also important to note that your ability to notice thirst typically diminishes with age.

Also of note:

• Sweating from exercise or high temperatures can result in more than 3 liters an hour of fluid loss.
• The maximum amount of water the body is capable of absorbing is 1 liter an hour or 330 milliliters every 20 min (the ideal amount to drink under high sweat conditions).
• Although good for energy, foods high in protein and sugar increase the body’s need for water.

Warning!

Drinking too much water is very dangerous! Over-hydration causes a sodium imbalance that can be fatal. It is common for marathon runners to be hospitalized because of overzealous hydration during the race.

Approach fluid consumption with moderation.

References:

Armstrong, L. E., & Epstein, Y. (1999). Fluid-electrolyte balance during labor and exercise: concepts and misconceptions. International Journal of Sport Nutrition, 9(1), 1-12.

Kleiner, S. M. (1999). Water: an essential but overlooked nutrient. Journal of the American Dietetic Association, 99(2), 200-6.

Lang, F., Busch, G. L., Ritter, M., Völkl, H., Waldegger, S., Gulbins, E., et al. (1998). Functional significance of cell volume regulatory mechanisms. Physiological Reviews, 78(1), 247-306.

Lieberman, H. R. (2007). Hydration and cognition: a critical review and recommendations for future research. Journal of the American College of Nutrition, 26(5 Suppl), 555S-561S.

Maughan, R. J., Shirreffs, S. M., & Watson, P. (2007). Exercise, heat, hydration and the brain. Journal of the American College of Nutrition, 26(5 Suppl), 604S-612S.

Murray, R. (1998). Rehydration strategies–balancing substrate, fluid, and electrolyte provision. International Journal of Sports Medicine, 19 Suppl 2, S133-5.

Suhr, J. A., Hall, J., Patterson, S. M., & Niinistö, R. T. (2004). The relation of hydration status to cognitive performance in healthy older adults. International Journal of Psychophysiology: Official Journal of the International Organization of Psychophysiology, 53(2), 121-5.

Staying Sharp by Keeping Fit

By Gregory Kellett, a cognitive neuroscience researcher at SFSU and science writer for Lumos Labs.

It turns out there may be a link between cardiovascular fitness and the size of one’s hippocampus, a portion of the brain important for the formation of new memories.

Researchers from the University of Illinois and the University of Pittsburgh, looked at the cardiovascular fitness of 165 adults between the ages of 59 and 81. They also measured (via MRI) the size of each participant’s hippocampus and tested for spatial reasoning abilities.

What they found:

• Elderly adults who are physically fit tend to have larger hippocampi than those who are less fit.
• Having a larger hippocampus is correlated with better performance on spatial memory tasks.

Exercise has been linked to hippocampus size and spatial memory in rodents, but this is the first study to demonstrate a similar relationship in humans.

This is good news because although variable between individuals, it is well established that the hippocampus typically shrinks with age and that this shrinkage is associated with subtle but definite declines in memory and spatial orientation.

References:

Erickson, K. I., Prakash, R. S., Voss, M. W., Chaddock, L., Hu, L., Morris, K. S., et al. (2009). Aerobic fitness is associated with hippocampal volume in elderly humans. Hippocampus.

Kitabatake, Y., Sailor, K. A., Ming, G., & Song, H. (2007). Adult neurogenesis and hippocampal memory function: new cells, more plasticity, new memories? Neurosurgery Clinics of North America, 18(1), 105-13, x.

Lumosity for your future offspring?

Could the brain training you do today help the memory of your children – even before conception? Research published today suggests that – surprisingly – this might actually be possible.

A study of brain function in mice reveals that a stimulating environment improves the memory of their offspring. If this improvement also occurs in humans, a mother’s youthful experiences may help shape her childrens’ ability to learn. Here’s the press release, with the paper reference below the fold:

Newswise — A study reveals that the severity of learning disorders may
depend not only on the child’s environment but also – remarkably – on
the mother’s environment when she was young. The study in
memory-deficient mice, published in the February 4 issue of The
Journal of Neuroscience, was led by Larry Feig, PhD, professor of
biochemistry at Tufts University School of Medicine and member of the
biochemistry and neuroscience programs at the Sackler School of
Graduate Biomedical Sciences at Tufts University.

The researchers studied the brain function of pre-adolescent mice with
a genetically-created defect in memory. When these young mice were
enriched by exposure to a stimulating environment – including novel
objects, opportunities for social interaction and voluntary exercise –
for two weeks, the memory defect was reversed. The work showed that
this enhancement was remarkably long-lasting because it was passed on
to the offspring even though the offspring had the same genetic
mutation and were never exposed to an enriched environment.

Previous research has shown that environmental exposures during
pregnancy can affect offspring. “A striking feature of this study is
that enrichment took place during pre-adolescence, months before the
mice were even fertile, yet the effect reached into the next
generation,” said Feig.

“The offsprings’ improved memory was not the result of better
nurturing by mothers who were enriched when they were young. When the
offspring were raised by non-enriched foster mothers, the offspring
maintained the beneficial effect,” said co-author Junko Arai, PhD,
postdoctoral associate in Feig’s laboratory.

“The effect lasted until adolescence, when it waned, suggesting that
this process is designed specifically to aid the young brain,”
continued Shaomin Li, PhD, MD, co-author, former postdoctoral
associate in Feig’s laboratory, now at Brigham and Women’s Hospital.

“This example of ‘inheritance of acquired characters,’ was first
proposed by Lamarck in the early 1800s. However, it is incompatible
with classical Mendelian genetics, which states that we inherit
qualities from our parents through specific DNA sequences they
inherited from their parents. We now refer to this type of inheritance
as epigenetics, which involves environmentally-induced changes in the
structure of DNA and the chromosomes in which DNA resides that are
passed on to offspring,” said Feig.

Previous research by Feig and his team showed that a relatively brief
exposure to an enriched environment in both normal and
memory-deficient mice unlocks an otherwise latent biochemical control
mechanism that enhances a cellular process in nerve cells called
long-term potentiation (LTP), which is known to be involved in
learning and memory. This enhancement was detected in pre-adolescent
mice but not in adult mice, reflecting the brain’s higher plasticity
in the young.

Feig concluded that the transgenerational inheritance of the effect of
an enriched environment may be a mechanism that has evolved to protect
one’s offspring from deleterious effects of sensory deprivation, which
may be particularly potent in the young and exacerbated in the
learning disabled.

Junko Arai and Shaomin Li, first authors, contributed equally to the
paper. Dean M. Hartley, PhD, of Rush University Medical Center is also
an author.

The work was supported by the National Cancer Institute of the
National Institutes of Health because these findings were derived as
an offshoot of the Feig lab’s long-term experience working on Ras
proteins that are involved in cancer. Fundamental principles of how
Ras proteins function gained by studying its role in cancer expedited
subsequent studies on Ras function in the brain. This work highlights
how major breakthroughs can arise by allowing researches to follow new
leads that cross disciplines. The work was also supported by the Tufts
Center for Neuroscience Research.

Arai J, Li S, Hartley DM, and Feig LA. The Journal of Neuroscience.
2009. (February 4); 29(5): 1496-1502. “Transgenerational Rescue of a
Genetic Defect in Long-Term Potentiation and Memory Formation by
Juvenile Enrichment.” Published online February 3, 2009, doi:
10.1523/JNEUROSCI.5057-08.2009

About Tufts University School of Medicine
Tufts University School of Medicine and the Sackler School of Graduate
Biomedical Sciences at Tufts University are international leaders in
innovative medical education and advanced research. The School of
Medicine and the Sackler School are renowned for excellence in
education in general medicine, special combined degree programs in
business, health management, public health, bioengineering, and
international relations, as well as basic and clinical research at the
cellular and molecular level. Ranked among the top in the nation, the
School of Medicine is affiliated with six major teaching hospitals and
more than 30 health care facilities. The Sackler School undertakes
research that is consistently rated among the highest in the nation
for its impact on the advancement of medical science.