Wundt curve
a bell-shaped curve illustrating that as a stimulus intensity (e.g., light) increases from low to moderate levels, its effect is pleasant or rewarding, but that as it increases to higher levels, its effect is unpleasant and even painful. The Wundt curve has been related to theories of human motivation, novelty seeking, and aesthetics, the latter most notably in the work of Daniel E. Berlyne. See arousal-reduction mechanism. [developed by Wilhelm Wundt]