Fluency, prediction and motivation: how processing dynamics, expectations and epistemic goals shape aesthetic judgements.

What psychological mechanisms underlie aesthetic judgements? An influential account known as the Hedonic Marking of Fluency, later developed into a Processing Fluency Theory of Aesthetic Pleasure, posits that ease of processing elicits positive feelings and thus enhances stimulus evaluations. However, the theory faces empirical and conceptual challenges. In this paper, we extend it by integrating insights from predictive processing frameworks (PPF) and the epistemic motivation model (EMM). We propose four extensions. First, fluency of a stimulus depends on perceivers' expectations-their internal model of the world. Second, perceivers also form expectations about fluency itself and thus can experience surprising fluency. These expectations can come from the individual's history, their current task and their environment. Third, perceivers can value fluency but also disfluency, reflecting their non-directional epistemic goals. Fourth, perceivers also have directional epistemic goals, preferring specific conclusions or belief content. Consequently, affective reactions depend on whether the stimulus satisfies those goals. These directional epistemic goals may override concerns about fluency or change the value of fluency associated with specific content. We review supporting evidence and introduce novel predictions. By integrating insights from PPF and EMM, our framework can better capture established fluency effects and highlights their limitations and extensions. This article is part of the theme issue 'Art, aesthetics and predictive processing: theoretical and empirical perspectives'.