Contextual Segmentation in the Visual Stream Produces a Temporal Synchronization Effect on Visual Perception

Abstract

Continuous temporal changes in environmental situations in everyday life can be segmented, in the perception process, into events. In this study, we examine whether contextual segmentation affects visual perception. Fodor and Bever (1965) discovered the temporal synchronization effect on speech perception of contextual segments in spoken language. We converted Fodor's auditory paradigm into a visual task by converting the auditory streams into visual streams, and the brief sounds into brief visual flashes. The detection of a similar temporal synchronization effect would strongly support the perception of a visual stream as the context of the visual event. We conducted two experiments using movies with natural scenes and edited scene segments to examine whether an explicit movie segment had a temporal synchronization effect on flash timing and whether changes in the action context had a similar effect. The results showed that the visual stream could be perceived within contextual segmentation. Key words: event perception, synchronization, visual contextWe can view our day-to-day experiences as a series of various events. An "event" can be interpreted as a fixed period during which a particular situation prevails; it may span a few seconds, a few minutes, or even a longer duration. However, the world around us does not stop; situations constantly change in a gradual manner. Therefore, an "event" or the "segmentation of an event" can be explained as the cognitive process of understanding the context of the environmental situations in the brain. In other words, we should have a segmentation process in our brain that can translate seamless continuous temporal information into a context of events.The contextual segmentation of complex information, which is known as the chunking mechanism, was studied with regard to language recognition and verbal learning (Gobet et al., 2001). Previous studies suggested that contextual segmentation in perception and memory developed by learning or repetition in order to recognize complex information. Studies from the visual domain showed that chunking in chess-piece