Thesis defense Xuyan Yun (Donders series 507)

1 October 2021

Perceptual appearance: Effects of features, structure and knowledge

Promotor: prof. dr. R. van Lier
Copromotor: dr. S. Hazenberg

The thesis aims to study perceptual appearances and how they can be influenced by local features, global structure and knowledge. The first experiment explores temporal properties of stimuli-related processing and percept-related processing in observing Fraser-like displays. Results show that there is no clear-cut segregation between such processing types. Next, the influences of local and global colour and contour properties on amodal completion of partly occluded geometric shapes are studied. The results show a clear influence of these factors and an increased influence of reasoning like processing for longer response times. Last, the influence of structural factors and knowledge at different points in time on amodal completion, on a set of well-known object is studied. From these studies I conclude that knowledge may kick in as soon as 150 ms after presentation of the stimulus. All in all, our results reveal the continuous interplay, and its evolvement over time, between various factors in the construction of visual appearances.