This morning in my inbox I find an interesting article by Art Markman on the question of what kind of creativity we display while our conscious minds are occupied with something else. It appears that for simple decisions, it's better to think about consciously it, however for complex issues it may be good to be distracted from the direct question. Dijksterhuis and Nordgren presented Unconscious Thought Theory (UTT) in this paper. Another paper by Haiyang Yang et al shows that the duration of unconscious thought has an inverted-U shaped relationship with creativity, suggesting that unconscious thought may outperform conscious for moderate-length deliberations.
So for quick decisions tis best to focus on the matter at hand. For very long and complex deliberations, there might be time for both conscious and unconscious contemplation. And to harness the power of unconscious synthesis thinking, one needs a moderate amount of time in which to do it.
I've heard of UTT before but not by name. I generally have my best ideas while walking, which suggests to me that cross-crawl integration of walking may bring the two brain halves to apply their knowledge to whatever problem is at hand. I've seen the process modeled extensively by television character Dr House. House plays ball, drives bumper cars, or does pranks on his coworkers to distract himself from the burning questions, and allow his unconscious mind to sort out the myriad details of a medical case and arrive at a diagnosis and treatment. People may think that he is goofing off, but in fact it is physical play that brings his most astounding ideas to the fore. He starts with the conscious brainstorming with the help of his team, then goes off to do whatever activity life presents, then returns to the conscious cogitation. The science is beginning to support the use of this technique for creative decisionmaking.