The neural mechanism supporting performance during single and feature conjunction detection was investigated using event-related brain potentials. In different blocks of trials, participants responded to visual targets defined by one of two colors, one of two orientations, or both color and orientation. Participants were faster and more accurate in detecting targets defined by a single feature than for targets defined by a conjunction of features. Compared with the single feature conditions, conjunction targets were associated with enhanced negativity between 230 and 270 ms post-stimulus and showed a delayed P3 latency. The relative timing of feature specific attention effects isolated in difference potential shows that feature conjunction occurs concurrently with the analysis of single features.