Walking Boost

Sat, 08/28/2010 - 23:07

You probably wouldn’t think that something as basic as walking several times a week could have such positive effects on a person. Science Daily reports on the importance of physical activity, and it’s connection to mental health. The brain works as a system, connections between different areas are vital to function properly. As we age, we begin to lose these connections. Physical exercise, even in mild forms can help prevent loss of these connections. Not only is this preventative, it also helps “enhance the connectivity of important brain circuits” and increases performance in cognitive tasks.

Neuroscientists have identified several distinct brain circuits. Perhaps the most intriguing is the default mode network (DMN), which dominates brain activity when a person is least engaged with the outside world -- either passively observing something or simply daydreaming.

Previous studies found that a loss of coordination in the DMN is a common symptom of aging and in extreme cases can be a marker of disease, Voss said.

"For example, people with Alzheimer's disease tend to have less activity in the default mode network and they tend to have less connectivity," she said. Low connectivity means that the different parts of the circuit are not operating in sync. Like poorly trained athletes on a rowing team, the brain regions that make up the circuit lack coordination and so do not function at optimal efficiency or speed, Voss said.

In a healthy young brain, activity in the DMN quickly diminishes when a person engages in an activity that requires focus on the external environment. Older people, people with Alzheimer's disease and those who are schizophrenic have more difficulty "down-regulating" the DMN so that other brain networks can come to the fore, Kramer said.

A recent study by Kramer, Voss and their colleagues found that older adults who are more fit tend to have better connectivity in specific regions of the DMN than their sedentary peers. Those with more connectivity in the DMN also tend to be better at planning, prioritizing, strategizing and multi-tasking.