A qualitative study focused on incubation and illumination within the act of writing to determine if life-span development affects image production during these creative, cognitive acts. Sixteen subjects of both sexes from four age groups represented major developmental stages in the life cycle. The research design provided two 90-minute sessions scheduled approximately four days apart with an incubation activity assigned between sessions. Writing activities and taped interviews occurred during both sessions to determine how each subject experienced imaging in the incubation and illumination stages of writing. Results showed that writers performed in recurring phases, often editing and formulating new thoughts at the same time. Two types of incubation operated in their writing patterns: (1) the recurring on-going incubation that is functioning while mental revising is taking place, and (2) the long-term incubation period that may go on for days, months, or years. The assigned incubation activity heightened awareness of the functioning of the unconscious. Even though life-span development appeared to affect subject matter of images, it appeared to have little effect on writing patterns. (DF)