The effect of attended color on the P1/N1 component of visual event-related potentials.

Ten subjects were asked to pay attention to green or to red, when each visual stimulus was presented as two small squares, one green and the other red. They were instructed to push a button with the right hand, when the attended color was on the right side, and to push a button with the left hand, when the attended color was on the left side. The P1/N1 peak-to-peak amplitudes of visual event-related potentials were significantly higher when subjects focused attention on green rather than on red. We assume that the attended color had the effect of modulating the P1/N1 components.