Abstract: The aesthetic objects arouse aesthetic pleasure that is specific and intense. The Pleasure-Interest Aesthetic model (PIA) suggests that aesthetic processing is a dual-process including the automatic process for sensory pleasure and the control process for aesthetic interest pleasure. Here we review recent work on the neural substrates of aesthetic pleasure. A large body of studies demonstrates that the orbitofrontal cortex is automatically activated by the objects of aesthetic appreciation. The orbitofrontal cortex which is responsible for automatic emotion regulation and reward processing of pleasure is generally activated in aesthetic activities and it is the neural basis of the automatic processing for sensory pleasure. Different modes of functional connectivity with the striatum support different aspects of aesthetic processing: the release of endogenous dopamine in the caudate nucleus is concentrated in the early aesthetic stage, and then gradually decreases during the in-depth process of aesthetic experience, while the release of endogenous dopamine in the nucleus accumbens gradually increases during the in-depth phase. This is evidence for the PIA model. However, additional brain circuitry is engaged such that the default mode network (DMN) is activated and the lateral prefrontal cortex is deactivated when the aesthetic flow experience occurs, indicating that beyond the dual-process highlighted by the PIA model there is a higher level of aesthetic flow pleasure. The automatic processing for sensory pleasure and the control processing for aesthetic interest pleasure are different from the aesthetic flow pleasure. Aesthetic flow pleasure is not the satisfaction of the needs of the senses, but the high-level pleasure which is liberated from the spirit; it is the experience of the soul gaining strength and courage and it is related to a clear self-consciousness. Therefore, aesthetic flow pleasure is independent of the automatic processing for sensory pleasure and the control processing for aesthetic interest pleasure. We point out that the PIA model needs to be expanded to include this dimension of aesthetic processing. The extended model includes three levels of aesthetic pleasure including sensory pleasure, aesthetic interest pleasure, and aesthetic flow pleasure. They are generated respectively in three stages of aesthetic appreciation: automatic processing, controlled processing, and integration and sublimation. Further studies should be conducted on how the aesthetic experience could impact upon creativity and to what extent different aesthetic experiences have the same or differential neural bases for giving rise to aesthetic pleasure.

Key words: neuroaesthetics, aesthetic pleasure, processing mechanisms, pleasure-interest aesthetic model