any steadily increasing degree of general arousal associated with or produced by contact with a stimulus that gives rise to a measurable hedonic (pleasure) effect. For example, a person listening to a piece of music might find it pleasurable precisely for the heightened anticipation induced by its harmonic structure. Compare arousal-reduction mechanism. [proposed in 1967 by Daniel E. Berlyne as part of his theory of positive hedonic value as a psychological effect of art]