Good to see some research being carried out into this.

As well as revealing that breaks on their own do not encourage creative thinking, Baird’s work suggests an explanation for one of psychology’s great mysteries: why we zone out.

From an evolutionary perspective, mind-wandering seems totally counterproductive and has been viewed as dysfunctional because it compromises people’s performance in physical activities. However, Baird’s work shows that allowing the brain to enter this state when it is considering complex problems can have real benefits. Zoning out may have aided humans when survival depended on creative solutions.

Reminds me of this Google Tech Talk by Nobel laureate Murray Gell-Man "On Getting Creative Ideas"