http://www.newsweek.com/neuroscientists-what-happens-brain-daydream-biology-memory-learning-1852066

A study has revealed tantalizing clues about what may be happening in the brain when we daydream—a question that neuroscientists are still trying to understand.

While the latest research, published in the journal Nature, was conducted on mice, the authors from Harvard Medical School (HMS) believe the findings could have implications for our understanding of the brain and its cognitive processes.