Less Food=More Memory?

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

Data collected by Agnes Flöel and her crew at the University of Munster in Germany seems to give yet another reason to resist that second helping of chocolate cake.

The research compared short-term memory performance of overweight individuals who reduced their caloric intake by 30% over 3 months with individuals who maintained their regular diet over the same 3 months.

Results:

• After 3 months, those on the decreased calorie diet improved by 20% on short-term memory tests of word recall.
• Participants who did not change their caloric intake showed no improvements.

The study coincides with multiple other studies demonstrating improved brain plasticity in animals fed calorie restricted diets. Some possible mechanisms at work include:

• The modified action of neurotransmitters
• The stimulation of neurogenesis (production of neurons)
• Increases in cell metabolism

However, in the above study, there may be other factors at work. As all the participants were overweight to begin with, the improvements could simply be due to an increase in overall health (IE blood flow, increased oxygen etc). Studies “starving” healthy individuals seem to be called for in order to eliminate this possibility.

References:
Caloric restriction improves memory in elderly humans. (2009, January 26). . Retrieved January 27, 2009, from http://www.pnas.org/content/early/2009/01/26/0808587106.

Fontán-Lozano, A., Sáez-Cassanelli, J. L., Inda, M. C., de los Santos-Arteaga, M., Sierra-Domínguez, S. A., López-Lluch, G., et al. (2007). Caloric restriction increases learning consolidation and facilitates synaptic plasticity through mechanisms dependent on NR2B subunits of the NMDA receptor. The Journal of Neuroscience: The Official Journal of the Society for Neuroscience, 27(38), 10185-95. doi: 10.1523/JNEUROSCI.2757-07.2007.

Stranahan, A., & Mattson, M. (2008). Impact of Energy Intake and Expenditure on Neuronal Plasticity. Neuromolecular Medicine.

Physical Exercise and Brain Blood Flow

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

Recent findings have linked exercising regularly with increased cerebral blood flow and a greater number of blood vessels in the brain.

While it has been shown in the past that aerobic exercise might reduce cognitive decline, this study demonstrated a possible explanation: changes in the brain’s blood vessels and blood flow.

The researchers recruited 12 healthy adults, age 60 to 76. Six of the adults participated in aerobic exercise for three or more hours per week over 10 years, and six exercised less than one hour per week. All of the volunteers underwent MRI to determine cerebral blood flow and MR angiography to depict blood vessels in the brain.

Compared to the inactive group, the people who exercised regularly had more small blood vessels carrying blood through the brain, and the blood flowed in a more normal pattern.

Exercising Executive Function

Think you’re good at multitasking? Many people believe they get more done by doing several things at once, but usually they’re wrong. Every time you switch to a different activity, you must give up a moment to shift your attention to the new task at hand. Overall, doing more than one thing slows you down.

While it’s a good idea to avoid multitasking in your day-to-day activities, some multitasking is simply unavoidable. So, we’ve designed Brain Shift to help you become better at efficiently switching between different activities. You should still avoid multitasking when possible, but we hope this exercise will make you better at it for those times when you must.

You can find Brain Shift here: http://games.lumosity.com/brain_shift.html

Let us know what you think!

Smoking and the Brain

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

A recent research review to be published in the journal Progress in Neuropsychopharmacology & Biological Psychiatry shows a link between cigarette smoking and adverse changes in the function and physiology of the brain. Summarizing the findings of dozens of experiments, the review indicates that:

• Strokes are more prevalent in smokers than non-smokers.
• Gray matter (made up of brain cells) shrinks in long-term smokers.
• Smoking is associated with less integrity in the white matter connecting brain hemispheres.
• Puffing tobacco can be bad for neurotransmitters.

There are a few factors clouding the picture however. These include the fact that alcohol consumption often accompanies cigarette smoking and has also been shown to have detrimental effects on the brain.

In addition there is the question of which comes first: brain abnormalities or smoking habits. It is possible that preexisting brain abnormalities increase the likelihood of smoking and addiction.  The author suggested more research in order to answer these questions, as well as to determine if these symptoms are reversible after quitting.

References:

Domino, E. (2008). Tobacco Smoking and MRI/MRS Brain Abnormalities Compared to Nonsmokers. Progress in Neuro-Psychopharmacology and Biological Psychiatry, In press.

Brain Game: By the Rules

This new exercise will work your mental flexibility, logical problem solving, and working memory abilities. We’re still putting the final touches on it, so send us your feedback so we can keep making it better.

You can find By the Rules here: http://games.lumosity.com/by_the_rules.html

The Biology of Learning

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

The field of neuroscience is just beginning to understand some of the physiological foundations of how we learn. The following is a basic breakdown of what we think we might know.

Learning is the process by which new knowledge or skills sticks to our brains.  Its functional “sticky” unit is the neuron. Neurons are cells specially adapted to communicate with each other. Everything we experience is reflected in the brain by neurons which communicate to form what are called neural networks.  These networks can be pictured as overlapping 3-D road maps which span brain regions responsible for processing everything from the bitter-sweet taste of dark chocolate to why your neighbor is such a grump. As we learn, these neural “road maps” interact and shift while also fading or strengthening in relation to our experiences.

Whether it be recognizing a co-worker or changing a flat tire, learning entails the formation and strengthening of connections or synapses between neurons. Brief experiences typically leave connections tracing an ephemeral neural network. This might be envisioned as crisscrossing deer paths. Which, if left unused, fade quickly.

After repeated exposure to a learning experience, like the second time we change that flat tire, the associated neuronal connections are reinforced, resembling more a network of single lane country roads than deer paths.  And when it comes to daily practice and expertise in a skill, one can imagine that the guy at the local tire shop would have the neuronal equivalent of intersecting super-highways.

This strengthening of neural network connections is thought to be the physiological basis of learning.

Changing, strengthening and creating new neural networks tends to get more difficult with age. There is some research, however, indicating that it is possible to maintain our ability to learn, and possibly even ward off or lessen the impact of certain types of dementia. It appears that a significant amount of age related cognitive decline can be attributed to a tendency to stay within pre-established comfort zones; shying away from new and challenging experiences, which typically push the brain to grow (or at least not shrink as fast).

Here are some simple tips that could help maintain our brain’s ability to adapt.

• Stay Social- Reaching out and staying connected with friends and family engages the mind.

• Break a Sweat- It’s not only good for your body but your head as well.  Regular aerobic exercise is even capable of stimulating the formation of new neurons.

• Relax- Certain stress hormones are damaging to the brain in excess.

• Seek Challenges- Take that swing dance class, it’ll keep you on your toes in more ways than one. Do a variety of the Lumosity brain games – don’t just focus on your favorites.

• Eat Fruits and Veggies- You’ve heard it a million times before; this time it’s because they contain anti-oxidants and other substances protective of your head’s contents.

• Review Your Day- Take some evening time to review what you did, who you met, and what you read about. Start with the present and work your way back to breakfast or vice a versa.

Brain Food Alert: Beware Tilapia!

We’ve previously recommended fish as a food that’s particularly good for your brain – in large part because it’s high in omega-3 fatty acids. While this holds true for many fish, one of the most popular, Tilapia, actually contains very little of the beneficial fatty acids according to new research from Wake Forest School of Medicine.

Instead, Tilapia is loaded with omega-6, which can cause inflammation that is bad for the heart. In fact, one of the authors of the study said, “the inflammatory potential of hamburger and pork bacon is lower than the average serving of farmed tilapia.”

So make sure your fish provides the right kind of fish fats! Some good options are Salmon, Mackerel, Trout, Whitefish, and Bluefin Tuna.

Good Cholesterol and Good Memory

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

A recent British study published by the American Heart Association suggests that the balance of cholesterol in our blood may affect not only heart health but also memory performance. It is widely accepted that diets promoting “Good” cholesterol, otherwise known as high-density lipoprotiens (HDL), can reduce cardiovascular disease, but it now appears that high HDL may also be good for memory.

Researchers tested 3,600 British civil servants for both HDL levels and memory performance over time, first at an average age of 55 and then again at 61.

The results?

• Participants with higher HDL levels did consistently better at recalling items from a list of 20 words after 2 minutes.
• For those whose HDL levels declined between tests there were also declines in memory performance.

Reference:

Singh-Manoux, A., Gimeno, D., Kivimaki, M., Brunner, E., & Marmot, M. G. (2008). Low HDL Cholesterol Is a Risk Factor for Deficit and Decline in Memory in Midlife. The Whitehall II Study. Arterioscler Thromb Vasc Biol, 28, 1398.