253 ALBERT N. KATZ Creativity and the Right Cerebral Hemisphere: Towards a Physiologically Based Theory of Creativity Highly creative people often discuss their creative acts as con- sisting of two parts. In one, a problem on which they had been working is suddenly perceived in a new way, old ideas are re- arranged, and a novel synthesis is achieved. The second part is a systematic confirmation, elaboration, .and communication of the earlier insight. Thus Poincare writes: One evening, contrary to my custom, I drank black coffee and could not sleep. Ideas rose in crowds; I felt them collideuntil pairs interlocked, so to speak, making a stable combination. By the next morning I had estab- v lished the 'existence of a class of Fuschsian functions ... I had only to write out the results, which took but a few hours (Ghiselin, 1952). Similarly Mozart wrote: ... the committing to paper is done quickly enough for everything is, as Isaid before, already finished; and it rarely differs on paper from what it was in my imagi- nation (Ghiselin, 1952). Other reports of separate perceptual insight and verbal elabo- ration of this insight are common (Lee, '1950; Ghiselin, 1952; Krueger, 1976). This partition of the creative act into two parts parallels those recent advances in our understanding of the human brain which differentiates between the processes for which each cerebral hemisphere is most efficient. The left cerebral hemisphere is specialized for thought processes which have been described as verbal, sequential, logical, and analytical (Bogen, 1969), whereas the right cerebral hemisphere is specialized for thought patterns which emphasize perception, synthesis, and the holistic rearrangement of ideas (Levy-Agresti & Sperry, 1968; Bogen, Volume 12 Number 4 Fourth Quarter