As most of us know from experience, if we concentrate too intensively on a
tough problem, we can get stuck in a mental rut. Our thinking narrows, and we
struggle vainly to come up with new ideas. But if we let the problem sit
unattended for a time—if we “sleep on it”—we often return to it with a fresh
perspective and a burst of creativity. Research by Ap Dijksterhuis, a Dutch
psychologist who heads the Unconscious Lab at Radboud University in Nijmegen,
indicates that such breaks in our attention give our unconscious mind time to
grapple with a problem, bringing to bear information and cognitive processes
unavailable to conscious deliberation. But Dijksterhuis’s work also shows that our unconscious thought processes don’t
engage with a problem until we’ve clearly and consciously defined the problem.
If we don’t have a particular intellectual goal in mind, Dijksterhuis
writes “unconscious thought does not
occur.” (Carr, The Shallows)