Unlike passive humor appreciation, the neural correlates of real-time humor creation have been unexplored. As a case study for creativity, humor creation uniquely affords a reliable assessment of a creative product's quality, subjects' expertise, and has a clear beginning and end, rendering it amenable to neuroimaging. Professional and amateur "improv" comedians and controls viewed cartoons in the scanner and, generated either a humorous or mundane caption. A dose-response function was evident such that funnier punchlines were associated with greater activation in temporal association regions (TMP) and the striatum but not the medial prefrontal cortex (mPFC). Greater comedic experience decreased activation in the striatum and mPFC, but increased activation in TMP. Less experienced comedians manifested greater activation of mPFC, reflecting their deliberate—but generally less successful—search through TMP association space. Professionals, by contrast, tend to reap the fruits of their spontaneous associations with reduced reliance on top-down guided search. Additional questions the talk will explore: What differentiates the neural signature of active humor creation from passive humor appreciation, and humor appreciation from a non-humorous "aha! moment"? Can mirth be explained in the context of a more general neural mechanism underlying human motivation for seeking novel information?