Repetition blindness (RB) is the finding that observers often miss the repetition of an item within a rapid stream of words or objects. Recent studies have shown that RB for objects is largely unaffected by variations in viewpoint between the repeated items.In 5 experiments, we tested RB under different axes of rotation, with different types of stimuli (line drawings and shaded images, intact and split), using both novel and familiar objects. Although RB was largely viewpoint invariant, in most experiments, RB was reduced for small (0°) and large (180°) viewpoint differences relative to intermediate rotations. However, these deviations from invariance were eliminated when object images were split, breaking the holistic coherence of the object. These findings suggest that RB is due mainly to the activation of object representations from local diagnostic features, but can be modulated by priming on the basis of view similarity.The human visual system is capable of processing tremendous amounts of information that vary across both spatial and temporal scales. In order to effectively guide the organism around its environment, important information must be detected and then attended to by conscious processes within very short periods of time. A striking phenomenological demonstration of this effect is perception of rapid serial visual presentation (RSVP) streams of objects. For example, participants can successfully detect a target object presented within an RSVP stream in which objects are replaced every 100 ms (Potter & Levy, 1969). This ability requires the fast activation of stored object information, and flexible attentional processes that can update quickly for each presentation.One important constraint on detection of objects within RSVP streams is repetition blindness (RB). If an object is repeated within a single RSVP stream, observers will often report seeing it only once. Thus, while conceptual knowledge about the object is activated, the observer seems unable to keep the two presentations separate in episodic memory. The first demonstration of RB used verbal stimuli, both within seemingly random lists of words and within meaningful sentences (Kanwisher, 1987). In both, repeated words were missed; in the latter context, participants sacrificed sentence grammaticality in failing to report the repeated item. Later experiments used pictorial stimuli instead of (or in conjunction with) verbal materials. For example, Bavelier (1994) investigated RB for both words and pictures. She found significant RB for both types of stimuli, though somewhat reduced in magnitude for pictures. She also found RB across changes in stimulus format, so that if the first critical stimulus (C1) was a picture of an object and the second critical stimulus (C2) was the name of the object, RB was still observed. This result is strong evidence that RB is caused by activation of stimulus information that is not tied to a particular format of presentation, but rather occurs at a deeper conceptual level.Explanations for repetition blindness...