Abstract
Perceptual categorization is a fundamental task in the human visual system. Although categorical judgements made by humans usually achieve high accuracy, many studies have suggested that human perception is dependent on perceptual history such that categorical judgements are influenced and not consistent in some situations. Here we are interested in this phenomenon by studying the categorization of ambiguous scene images in continuous transitions between scene categories. We created synthesized in-door scene images based on three categories: bedroom, living room and dining room. Participants were shown sequences of scene images that smoothly changed from one category to another and were asked to respond when they perceived a change in category. Each sequence was shown in two directions such that both transitions from category A to B and B to A were presented, and the differences in the categorical responses in the two directions were compared. Participants were also shown sequences of abrupt changes with sudden shifts between categories, and these responses were used to estimate response time. We predicted the perception of the scene category to be biased toward the starting category in a transition. Our results confirm this prediction: participants’ perception in the two directions for the same transition was different such that the perceived category change was delayed, and the ambiguous scene images tended to be categorized as the starting category of a transition, thus giving rise to a perceptual hysteresis. This study found evidence that the same stimuli can be interpreted in different ways for categorical judgement. During dynamic changes of stimuli, the human visual system tends to persist in the current interpretation when resolving ambiguities. This implies that in scene perception, instead of a tendency to shift the perception, a stable perception is preferred by the human visual system in dynamically changing environments.