2007 年 25 巻 2 号 p. 273-274
When two identical visual objects move across each other in a two-dimensional display, there is a perception of streaming through, or bouncing off each other, at the position of their coincidence. In our preliminary observation, a switch of object features such as color between the two objects, biased the perception towards bouncing. We have examined the characteristics of spatiotemporal integration of object features in the stream/bounce event. By changing the duration of the object presentation after a color switch at their coincidence we explored the spatiotemporal properties of object color to substantially affect the stream or bounce event. The results revealed that 100 ms after the color switch, the observers can utilize the color change information to determine the stream/bounce event. Additionally, the percentage of bouncing percepts reached a maximum rate 150 ms after the color switch. A follow-up experiment showed that the results were not affected by the speed of the objects. This result sugges ed that the post-coincidence duration is crucial for spatiotemporal integration of the object color feature in event perception.