Abstract
How do we achieve stable and continuous perception of the objects around us despite ever-changing visual input? One mechanism for stability may be serial dependence in visual perception. We have previously shown (Fischer, Shankey, & Whitney, VSS, 2011) that the perception of basic features (e.g., orientation) depends not only on current visual input, but also on prior input extending back 10 or more seconds. Serial dependence is a potential mechanism for stable object perception, but a key unanswered question is whether it operates beyond the level of basic features. Here, we used face stimuli to test for serial dependence at the level of holistic object information. In these experiments, faces were drawn from a continuous morph of facial identities and subjects were asked to report their perception of identity in (1) an adjustment task and (2) a two-interval forced choice task (2IFC). In the adjustment task, subjects adjusted the identity of a test face to match the identity of a target face they had just seen. Subjects made consistent perceptual errors when reporting the perceived identity of the target face on the current trial, seeing it as more similar to the identity presented on the previous trial. In the 2IFC task, the target face for each trial was drawn from a subset of morphs between identity A and identity B, and subjects determined if the target face or a subsequently presented probe face was more A-like. Subjects were more likely to report the target face to be more A-like if the target on the previous trial was relatively more A-like, and vice versa. Using two different tasks, we have converging evidence that current perceived identity is attracted to previously encountered identities. Therefore, serial dependence does occur at the object level, contributing to our stable representation of objects.
Meeting abstract presented at VSS 2012