Abstract
Human visual system is very fast and efficient at extracting information about objects present in complex natural scenes. For example, event-related potential studies have shown that the underlying processing required to decide whether a briefly flashed natural scene contains an animal can be achieved in 150 ms (Thorpe, Fize, & Marlot, 1996). The results implied that a great deal of visual processing must have been completed before this time so that complex processing of visual categorization in natural scenes can be achieved. An interesting question is what makes such rapid object recognition possible. Here we carried out two experiments to investigate whether the contextual information provided by the scene contributes to rapid object categorization. In Experiment 1, participants were asked to view briefly flashed scenes and performed a go/no-go animal/nonanimal categorization task. In Experiment 2, participants performed a two-alternative forced choice task in which they had to decide whether a flashed scene contained an animal or not. In both experiments, we examined the influence of contextual information either by retaining or deleting the original scene background. The results of the two experiments showed that the reaction times were significantly faster for animals appearing with a scene background. The current findings demonstrate that scene context bolsters rapid object categorization in natural scenes.
This project was supported by grants from the NIH and the NSF.