How processing of visual symmetry relates to preference for regular patterns, and the role of attention on preference formation

摘要

The process of preference formation is influenced by many factors. These include intrinsic stimulus attributes as well as contextual factors, which are not directly related with the stimulus itself. In this PhD thesis I present seven studies that give significant new insights about how human preference is affected by intrinsic stimulus properties, as well as contextual factors. The common denominator is the use of abstract shapes forming regular patterns (reflectional symmetry). The presence of symmetry within the stimuli predicts preference, and there is behavioural evidence of an association between symmetry and positive valence. The first study shows the neural basis of this association (Part 1, Chapter 2). The thesis proceeds with four studies (Part 2, Chapters 3 – 6) exploring the role of (exogenous) attention on preference evaluation of abstract shapes that already contain intrinsic valence (symmetry/random). Previous research has demonstrated that attention plays a major role on preference formation. These studies showed that exogenous orienting of attention led to more positive evaluation of stimuli at cued locations, although this effect was sensitive to endogenous control. In the last part (Part 3), Chapter 7 explored preference devaluation of abstract symmetry with increasing visual eccentricity, as a potential consequence of reduced perceived regularity at farther locations. Random shapes, which do not lend themselves to coherent interpretation at fovea, were similarly evaluated at all eccentricities. Chapter 8 did not focus on preference. With a novel design, it explored how symmetry detection speed in the periphery was affected by the way attention was deployed in visual space. Overall these findings confirm the role of symmetry in aesthetic appreciation of abstract shapes. Importantly, they highlight a role of attention orienting and gazing in preference modulation. Defining what factors determine preference is key to understanding human behaviour and decisions. This thesis provides a significant contribution towards this goal.