The Default Mode Network and Brain Fitness

If brain fitness is more than just trying to avoid memory loss as you get older (and I think it is), then understanding how you think is (I think) critical. Sometimes called metacognition, this means not just thinking, but thinking about thinking.

Follow that? Metacognition is the idea that we can understand not only the content of our thinking, but the different processes that go into it. And understanding the ways that the default mode network and focused attention (both ways of thinking) interact are the subject of several interesting article.

The default mode network is a group of brain structures that become more active when someone’s attention is focused inward, thinking about what happened in the past or what might happen in the future. When a person’s attention is focused on the outer world, a different set of brain structures is activated.

A recent article in Neuroimage (click here for link) suggests that people who are less efficient in making the transition between the two sets of structures may be more creative. It’s as though the person’s internal world intrudes on reality. This finding has some appeal, because it helps us understand how creative persons can look at everyday life and see something radically different. It also helps us understand how someone’s unique individual vision can be so compellingly imposed on existing reality.

You don’t have to look very far to find examples. My personal favorites are Stanley Kubrick’s vision of the future in 2001, Fritz Lang’s in Metropolis, and the entire Dr. Who series from the BBC. Take an ordinary telephone call box, the vision of a sexy robot in the future, or a nghtmare of artificial intelligence, and extrapolate.

How do you apply this to your own brain fitness? Research shows that creativity, or at least its close relative, divergent thinking, can be taught, even to kindergarten-aged children. Jonah Lehrer wrote a recent article in the Wall Street Journal and a related blog post about the virtues of distractibility.

For optimal brain fitness, consider training yourself in divergent thinking.

Walking, BDNF, Hippocampal Size, and Brain Fitness

Maybe I have an obsession. Maybe I’m addicted to exercise. Maybe.  But here it is, once again: Yet another study has shown that aerobic exercise is good for your brain. Not only does aerobic exercise improve cognition (at least 20 or more studies have shown that), but it can help to prevent age-related declines in the size of the hippocampus. The hippocampus is a critically important structure in the brain that is a key part of a circuit that creates new memories.It tends to get smaller with increasing age, but exercise can actually increase its size. The increase in size may be related to increased levels of brain-derived neurotrophic growth factor (BDNF), a substance in the body that promotes the growth of new brain cells.

In an article published online on January 31st in the Proceedings of the National Academy of Sciences, researchers show again that regular walking can make a difference in cognition. This study is new because the researchers also looked at the volume of the hippocampus with imaging techniques and looked at BDNF levels.

Exercise and BDNF levels may also be related to the way that antidepressants work to reduce depression, and we know that for many individuals exercise improves mood. While we think of the hippocampus most often because of its role in memory, it also has important effects in regulating emotion.

You can find the abstract here. The full article is available to subscribers only.