Guri, O. . , Gertsovski, A. & Ahissar, M.
The Hebrew University of Jerusalem
Visual serial dependence is a phenomenon in which the perception of a stimulus is biased toward the most recently seen stimuli. Serial dependence was reported for various visual objects and their features, such as orientation and movement of lines, numerosity of dots and faces identity. We now study the dynamics of serial dependence for faces, by manipulating both the duration of stimulus presentation and Inter-Trial-Intervals (ITI). We created morphs of two faces (face A and face B) and participants were asked to categorize each morph as one of the two faces. As expected, categorization looks sigmoidal. We calculated categorization of the stimulus for which the participant's categorization performance was closest to chance level. Serial dependence was calculated as the difference in categorization between trials in which the previously seen stimulus was more similar to face A and those in which it was more similar to face B. When stimulus presentation was comfortable (~2sec), the magnitude of serial effect peaked at ~6 sec ITI, whereas when stimulus presentation was short (<2 sec) the effect was apparent faster but it lasted for a shorter interval. Our results suggest that when stimulus sampling is shorter and hence noisier, serial dependence kicks in earlier.