In a typical redundant-target experiment, participants are asked to respond to events of two modalities, which are presented either alone or simultaneously (Miller, 1982). Combined (bimodal) stimuli are called redundant because the same reaction is required for both targets, irrespective of their modality. Reaction times (RTs) to redundant targets are commonly found to be shorter than RTs to simple (unimodal) targets. Two alternative models have been suggested to explain this redundant-target effect (RTE). Separate activation models, or race models, hold that the two components of a bimodal event are processed in separate channels and that the channel that has first finished processing first triggers the response. By analogy, the probability of obtaining a six is higher when two dice are tossed instead of one. Similarly, the probability of getting an RT, t, lower than a given t 0 is higher for bimodal (e.g., auditory-visual, AV) than for unimodal (A or V) stimuli, resulting in a lower mean RT. This effect has been called statistical facilitation (Raab, 1962; see Figure 1). Given the RT distributions to simple stimuli, the redundancy gain that can be explained by statistical facilitation has a clearly defined upper limit, which is described by the race model inequality (Miller, 1982):A race model requires that this inequality should hold for the cumulative RT distributions for both unimodal and bimodal stimuli. If the redundancy gain surpasses that predicted by the race model, rejecting the race model in favor of a coactivation model is justified. Proponents of the latter model disagree with the separate processing view and suggest that information from the two modality channels is integrated at a particular processing level and subsequently processed as a combined entity. This processing stage gains from redundant information, resulting in faster responses to redundant stimuli.The race model is typically sufficient to explain the redundancy gain of healthy participants in simple unimodal detection tasks with two classes of visual stimuli (see, e.g., Corballis, 1998Corballis, , 2002; a weak violation was found by Miniussi, Girelli, & Marzi, 1998, which was, however, not statistically tested). Surprisingly, split-brain patients have displayed redundancy gains larger than those predicted by the race model when bilateral stimuli have been used (Corballis, 1998(Corballis, , 2002Reuter-Lorenz, Nozawa, Gazzaniga, & Hughes, 1995;Roser & Corballis, 2002 Participants respond more quickly to two simultaneously presented target stimuli of two different modalities (redundant targets) than would be predicted from their reaction times to the unimodal targets. To examine the neural correlates of this redundant-target effect, event-related potentials (ERPs) were recorded to auditory, visual, and bimodal standard and target stimuli presented at two locations (left and right of central fixation). Bimodal stimuli were combinations of two standards, two targets, or a standard and a target, presented either from the same or from diff...