Focused and diffuse modes of thinking- a brief on how it functions

[lectured by Barbara Oakley, PhD, PE.; Video courtesy- Coursera lecture series 'Learning How to Learn']
In this video Dr.Barbara describes how the diffused mode allows the brain to explore newer ways of thinking, than being restricted by older familiar thoughts, hence resulting in creative encounters.  
Talks about how Thomas Edison & Salvador Dali used Focused and diffuse modes of thinking for problem solving