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

The power of brain plasticity

This article was contributed by Paul Li, who teaches cognitive science at UC Berkeley.

The human brain is quite remarkable. It does not remain static, but instead ceaselessly changes throughout life. Everything you learn or experience impacts the biology of your brain.

Though some cognitive abilities typically begin to decline in the third decade of life, cortical plasticity renews our hope that new connections can be willfully forged. For example, there was a little girl who was born with very little cortical tissue. Doctors did not see much of a future for her because she did not have a “normal” brain; however, because of cortical plasticity and the brain’s ability to reorganize itself, she learned to function quite well (Distelmaier et al., 2007).

The article highlighted that this “case teaches us that clinicians and parents should not give up in the face of an apparently hopeless case!”

In a previous post, Almost No Brain, a man managed to lead a normal life despite having minimal gray matter inside his skull. These two cases show how amazingly adaptable the brain is. The ability to shift the nature-nurture tension toward the nurture side is empowering for us, and provides hope even in the face of serious abnormalities of the brain.

References:
Distelmaier et al., “How Much Brain Is Really Necessary?” A Case of Complex Cerebral Malformation and Its Clinical Course, J Child Neurol 2007; 22; 756

Special thanks to Bradley Voytek, Helen Wills Neuroscience Institute, Berkeley, for his assistance.

Your Nervous System at Work

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

Ever wonder about the workings of your nervous system?  As mentioned in our previous post on cognition, the nervous system is responsible for integrating and processing information about your surroundings while directing action towards the achievement of goals; whether this be eating a tuna sandwich, serenading a lover or getting out of the way of a speeding bus. Physically, it is made up of your brain, spinal cord and peripheral nerves.

Let’s look at the structural components of this biological orchestra.

Neurons and Glia
The basic functional units of the nervous system include neurons (cells who’s primary job is to communicate) and glia (cells which support neurons and their communication).

The average brain has about 100 billion neurons and about 9 times as many glia.

Neurons (with the help of glia) connect and coordinate senses such as sight, hearing, smell, touch and taste with the activity of your muscles and organs. They are either taking information in for integration, communicating with other neurons for information processing, or sending information out to generate action.

Glial cells (of which there are multiple types) do a variety of tasks to support the functioning of neurons, including removing waste, providing nutritional and structural support and facilitating connections. Some glia have also been shown to communicate with neurons, as well as each other, in order to help coordinate neuronal activity.

Synapses and Neurotransmitters
Synapses are the actual locations at which neurons communicate with each other, and a typical neuron has about 10,000 of them.

Neurons communicate at synapses through the use of neurotransmitters. Neurotransmitters are chemicals sent between neurons as well as the muscles and organs they work with. They attach to receptors on receiving cells, translating into one of three basic types of messages:

•    Excitatory- Encouraging connected neurons and other related cells to “pass it on” or activate; perhaps prompting you to swat at that fly after being buzzed by the umpteenth time or dilate your pupils when the lights go out.

•    Inhibitory- Suggesting that the receiving cell not continue passing on the signal or take action. This could be involved in the shutting down of appetite in response to the non-acquired taste of anchovies or the ability to ignore the radio in your car while figuring out how to get un-lost.

• Adaptive- Instructing a neuron to change something in its structure or the way it functions. This is the basis of plasticity where neurons may reduce or increase the number of connections, move them around and or adjust their sensitivity; all of which are part of the learning process.

Neural Networks

Neurons which collaborate on a specific physiological function, such as hearing high pitches, moving your pinky or remembering to take the trash out, are considered to be part of a shared neural network. Typically these functionally related neurons will use only one or two of the over 100 different types of neurotransmitters available. Neurotransmitters, however, can and often are associated with several types of neural networks.

Serotonin is an example of a neurotransmitter involved with the regulation of multiple systems including mood, appetite, temperature, pain sensation and sleep.

Dopamine is the neurotransmitter of choice for neural networks dealing with reward, such as the feeling you get after winning an egg toss or eating a delicious meal. It is however also used by circuits involving memory and attention.

Complexity
As much as we do know about how our nervous systems work, there is still much more to be discovered. One of the many areas where little is known involves how different neural networks, responsible for such diverse tasks as detecting movement, recognizing objects and generating action, can communicate between themselves. The mechanisms involved in coordinating the information from different specialized neural systems into a seamless experience of say, catching a ball, is still a mystery.  This is referred to as the binding problem, and although there are plenty of theories, there are no clear answers as of yet.

As you can see, the interactions between our neurons, neurotransmitters and constantly shifting surroundings are complex…..especially when they are trying to grasp the complexity of interactions between neurons, neurotransmitters and constantly shifting surroundings;)

What is Cognition?

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

What exactly is cognition and how does it work? Here we will attempt to outline and explain some of the basic concepts involved with the inner workings of your head.

Cognition literally means “to know”.  Knowledge can be thought of as memories formed from the manipulation and assimilation of raw input , perceived via our senses of sight, hearing, taste, touch and smell.

Using knowledge to direct and adapt action towards goals is the foundation of the cognitive process. Past experiences and trends inform our sense of what the future might hold and help us to act accordingly.

Take a yearning for pizza for example… Cognition encompasses everything from knowing/remembering what pizza is (and that you like it)…to realizing that you are hungry and making plans to have it delivered.

In order for our finite minds to make sense of the near infinite details of our surroundings however,  a large part of cognition involves the organization of our thoughts into associations or categories. These might range from “things one might find in a kitchen” to “people I think are cute”. Simple symbols such as the word “face” are used to group more complex learned associations such as those between noses, lips, eyes and smiles.

Although important, these “cognitive categories” are overlapping and not always clearly distinct…so keep this in mind as we break down the concept of cognition itself into some of its more widely recognized pieces.

The words perception, attention, memory and executive function are one way of divvying up the processes involved in how we think. All of the above will be involved throughout your journey towards satisfying that pizza craving. Let’s use some specific points to illustrate their role in the overall process of attaining such a dinner goal.

Perception, in this case, of the fact that you feel hungry and that there is no food in the fridge, is what gets the whole process moving. It involves seeing, hearing, feeling, tasting and or smelling your surroundings, allowing you to respond appropriately.

Memory plays the obvious role of storing the name of your favorite pizza parlor. It also enables you to dial the number given by the operator and give directions to your house. Some different components include short term/working memory, long-term memory and subconscious/implicit knowledge.

Executive Function enables the planning of logistics, such as timing the pizza delivery to coincide with the arrival of your scrabble buddies.  Improvising (guessing what toppings everyone will enjoy), problem solving (figuring how much to tip) and controlling impulses (not ruining your appetite by eating a whole bag of Doritos while waiting) also come into play here.

Attention processes kick in by having you shift your focus from reading the Sunday funnies to answering the door upon hearing that long awaited knock. They also help in multi-tasking a slice of pizza with figuring out how to nail that triple word score all while ignoring the heckling antics of your so called “friends”.

Again, although separated for the purposes of our discussion here, it is the interplay of all of these systems working simultaneously which makes up the process of cognition; allowing us to adapt to our surroundings and take action towards obtaining our goals.

New Brain Game – Top Chimp!

We’re on a roll! Following the debut of Name Tag last month, we are now ready to release Top Chimp, a brain game that sharpens visual attention and trains working memory. We think it’s more fun than a barrel of…well, monkeys, but would love to have your feedback before the game becomes part of the regular set of brain exercises. Please find the game here http://games.lumosity.com/top_chimp.html and send any suggestions to games@lumosity.com.

Long-term and Working Memory – You Are What You Remember

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

Memories are vital to our ability to function on even the most basic of levels. Our respective “realities” are in fact a large part due to the constantly shifting kaleidoscope of our remembrances. Here we will touch briefly on the difference between short-term/working memory and long-term memory as well as how the two filter and add meaning to our worlds.

What if we could remember everything we experienced? As enticing as it sounds, our finite brains would quickly find themselves overwhelmed with the random details of yesterday’s weather forecast alongside the nutritional information off of last month’s box of raisin bran.

Thankfully, the vast majority of our memories are fleeting mental wisps lasting only seconds to minutes. These temporary impressions make up what is called short-term or working memory.

Working memory can be thought of as a staging area where the mind takes meaning from such items as:

• Specific immediate memories of very recent sensory input (IE the sour smell of expired milk).
• The temporary recollection of details from long-term memories (IE what happened the last time you drank sour milk).
• Conclusions and ideas made in the past (Sour milk is bad).

Notice how working memory can temporarily pull details from long-term memory for short-term use. Although constantly changing and ephemeral itself, working memory is vital to our ability to make decisions and take action over time (such as our pouring that sour milk down the drain). For a brilliant and more in-depth description of working memory read Elizabeth Buchen’s “Working Memory: What it is and how it works”.

When an experience or piece of information sticks and doesn’t evaporate with short-term memory, it is said to have entered into the realm of long-term memory. This journey is called consolidation and takes place after prolonged exposure to a piece of information or experience. The longer the exposure, the better the consolidation, the more robust the related memories will be.

Long-term memories can store much larger quantities of information than working memory and for much longer periods of time (often as much as a lifetime). These resilient long-term recollections are made up of both consciously learned facts, such as “Madrid is the capital of Spain” and subconsciously learned knowledge, such as the ability to balance and ride a bike.

We derive meaning and the ability to act via the synergistic relationship between long-term and working memory. Working memory combines elements from our long-term stores with immediate sensory information in order to generate ideas and plans of action. For example, remembering that the taste of peanut butter is pleasant as we toast toast, might just have us use our memorized skill of unscrewing a jar in order to manifest the pleasurable experience of peanut butter on toast. Which is just one more potentially delicious result of a fit and active mind.

Brain activity across languages

By Lumos Labs Science Associate, Paul Li, MS Neuroscience.

Different languages are represented differently across the brain. This is especially true for languages that are very dissimilar, such as English and Chinese. English is learned from pronouncing its 26-letter alphabet, whereas to learn the Chinese language, one needs to memorize thousands of characters in order to understand a string of pictographs.

Dyslexia, a learning disability that causes difficulty in reading and writing, affects the brain in different ways according to language. Professor Li-Hai Tan, along with his research team from the University of Hong Kong, discovered that Chinese-speaking dyslexics have a different pattern of brain activity than English-speaking dyslexics. Professor Tan told Lumos Labs that “the left middle frontal gyrus, rather than the posterior brain regions, is a perpetrator of reading disorders in Chinese, suggesting the possibility that a person who is dyslexic in Chinese reading would not be in alphabetic language reading, and vice versa.” One implication is that different interventions may be more or less suitable depending on language.