The Neuroscience of Idle Minds

http://www.nature.com/news/neuroscience-idle-minds-1.11440

This article explains how the brain is active when at rest and considers the implications of this. 

There is a myriad of activity occurring in our brains, even as we sleep. It is important to distinguish, however, between brain activity and conscious thoughts. Just because a person is having (or thinks he is having) no conscious thoughts, or even if he is unconscious, there is still masses of activity flowing through his brain. 

I think they will find that while our brains rest - whilst we are lounging idly on the sofa, for example - our brains are consolidating memories formed throughout the day. So, it's probably best to take a break after studying and do nothing, rather than watch TV, or socialise, even. 

I also reckon memories aren't, as previously thought, merely set pathways through which a current flows which make up a conscious recall of a stimulus. I think they can change, and perhaps 'exist' in many places at once, constantly being reformed and manipulated through processes such as neuroplasticity. 

It is also suggested that the brain can reuse past experiences to 'prime' connections which may be useful in the current situation. For example, if we are crossing a busy road, not only would we be consciously aware that we are in danger, but the motor sections of our brain would be primed so that we are more prepared to dodge that oncoming bus. 

I particularly like the analogy: 

“If your car is ready to go, you can leave faster than if you have to turn on the engine.”

The brain is surprising similar to any other machine; yet vastly different and infinitely complex.