Image aesthetic pleasure (AP) is conjectured to be related to image visual complexity (VC). The aim of the present study was to investigate whether (a) two image attributes, AP and VC, are reflected in eye-movement parameters; and (b) subjective measures of AP and VC are related. Participants (N=26) explored car front images (M=50) while their eye movements were recorded. Following image exposure (10 seconds), its VC and AP were rated. Fixation count was found to positively correlate with the subjective VC and its objective proxy, JPEG compression size, suggesting that this eye-movement parameter can be considered an objective behavioral measure of VC. AP, in comparison, positively correlated with average dwelling time. Subjective measures of AP and VC were related too, following an inverted U-shape function best-fit by a quadratic equation. In addition, AP was found to be modulated by car prestige. Our findings reveal a close relationship between subjective and objective measures of complexity and aesthetic appraisal, which is interpreted within a prototype-based theory framework.

Computational views of perception do not consider affect to be required to solve a perceptual task. Previous research provided evidence for an affective component in early perceptual processes, but it is unclear whether late perceptual processes yield concomitant affect. Three studies using three different tasks explored changes in affect related to late perceptual processes by exposing participants to a visual object and measuring activity in facial muscles (zygomaticus major and corrugator supercilii) using facial EMG as indicators for affect. In the first task, change of muscle activity was measured before and after participants indicated that the perspective of bistable illusions shifted. In the second task, change of muscle activity was measured before and after participants indicated that they identified an object that emerged from a pattern mask. The third task examined the affective consequences, as measured by facial EMG, of solving mental rotation tasks. The three studies found that shifts in bistable illusions, identification of objects, and solving mental rotation problems yielded increasing zygomaticus major activity, indicating increased positive affect after task completion. Simultaneously, corrugator supercilii activity decreased after successful perception. These studies suggest that success in perception is inherently affective, even when memory, comparison, and decision processes are involved. Public Significance StatementAlthough computational models of perception do not consider affect to be necessary to solve a perceptual task, previous research found affective responses concomitant with early perceptual processes. However, it is unclear whether affect goes along with later perceptual processes that include categorization, memory, and decision processes. This study explores affect in later perception by measuring activity of the zygomaticus, the smiling muscle. Across three studies, we provide evidence in support of affect being a general consequence of successful perception even in complex tasks that include complex cognitive processes.