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Abstract

Are detection, categorization, and identification of upright images of natural objects mediated by the same or different visual processes? Surprisingly, previous studies found that object detection is as fast as object categorization while object identification takes significantly longer. This suggests that object detection and categorization are mediated by the same visual processes while object identification is mediated by different visual processes (eg Grill-Spector and Kanwisher, 2005 Psychological Science 16(2) 152 - 160). We compared (a) the time course of object detection, categorization, and identification of upright object images using a higher temporal resolution than in previous studies (Experiments 1 and 2); and (b) the sensitivity of these three recognition processes (Experiment 3). Participants saw two consecutive image presentations of which one contained an object image and the other a patch of visual noise. On every trial participants reported the object interval (detection), the object's category (categorization), and the object identity (identification). We measured participants' accuracy to conduct each of these tasks as a function of presentation time (Experiments 1 and 2), and signal-to-noise ratio (Experiment 3). We found significant differences between the psychometric functions of object detection, categorization, and identification in all three experiments. We conclude that detection, categorization, and identification are separable component processes of object recognition.