Finally, as suggested by existing behavioral

work (Pinto et al., 2005 and Becker, 2007), attention should be misallocated to the salient distractor when the colors defining the target and distractor swap between trials, and this should be evident in a BTK screening distractor-elicited N2pc (Hickey et al., 2006 and Hickey et al., 2010a). This would suggest that the activation of target features and/or suppression of distractor features involved in target resolution has a residual impact on visual processing, resulting in a net benefit for the processing of features that have characterized the target. When the colors swap between trials, and the primed color comes to characterize the distractor, this will benefit resolution of the distractor at the expense of the target. The salient distractor slowed target response (absent RT: 820 ms, present RT: 902). Swap trials were 19 ms slower than no-swap trials in the distractor present condition (no-swap: 893 ms, swap: 912 ms) and 6 ms in the distractor absent condition (no-swap: 817 ms, swap: 823 ms). A repeated measures analysis of variance (RANOVA) with factors for distractor presence (present vs. absent) CHIR-99021 and intertrial condition (swap vs. no-swap) identified a main effect of distractor presence (F(1,11) = 21.089, p < 0.001), a marginally significant effect of intertrial condition (F(1,11) = 3.724, p = 0.080), and a marginally significant interaction between factors (F(1,11) = 3.822,

p = 0.077). A planned contrast of the simple effect of intertrial contingency in the distractor-present condition confirmed the reliability of the intertrial effect in this condition (t(11) = 2.530, p = 0.014). Analysis of error revealed no significant effects (distractor present no-swap: 8.2%, swap: 8.9%; distractor absent no-swap: 8.0%, swap: 7.3%; Suplatast tosilate distractor presence: F(1,11) = 1.608, p = 0.231, all other Fs < 1). Our expectation was that the N2pc would increase in magnitude when a salient distractor

was included in the visual search display and attention was deployed to the target. The results show that the presence of the salient distractor in fact had two effects on the N2pc, causing an increase in amplitude and a general broadening and shift of the topography towards more posterior and lateral visual cortex (cf. topographic maps in Fig. 1a and b). There is little in the way of an N2pc apparent at posterior electrode locations in the no-swap, distractor absent condition (Fig. 1a), but the component is clear in the divergence of ipsilateral and contralateral waveforms between 280 and 360 ms in the no-swap, distractor present condition (Fig. 1b). To test the reliability of this increase in the posterior aspect of the N2pc we conducted a three-way repeated measures analysis of variance (RANOVA). This analysis was based on mean amplitude in the no-swap conditions measured from 280 to 360 ms with factors for electrode location (ipsilateral vs.