“Background motion silences awareness of foreground change”

When a set of objects changing in brightness, color, size, or shape moves across the visual field, the objects appear to stop changing [Suchow & Alvarez, 2011]. In previous work introducing this effect (“silencing”), we showed that its strength depends on speed: the faster the objects move, the less noticeable the change. (See the demos at http://bit.ly/cW0YCB.) In order to explain it, we had proposed the brief window hypothesis, which supposes that change detection relies on the success of local detectors—i.e., ones that monitor a fixed location in the visual field. Then, since a fast-moving object spends little time at any one location, each detector is afforded only a brief window in which to assess the changing object; this brevity may preclude the detection of change. Here, we show that the brief window hypothesis is wrong via a demonstration of silencing by background motion.

1. Suchow, J. W., and Alvarez, G. A. 2011. Motion silences awareness of visual change. In Current Biology, vol. 22, 140–143.