Figure 6.

Distributional differences of extracted auditory response as a function of SOA and visual-stimulus laterality. A, Topographic voltage distributions for the spreading-of-attention effects on the extracted auditory response for each SOA condition, shown separately for the left and right visual stimuli. These spreading-of-attention effects were derived as in Figure 4 from difference waves between the auditory ERPs extracted from when the associated visual stimulus was attended versus when it was unattended (i.e., as in Fig. 5, the responses to the respective visual-only stimuli have already been subtracted). Clear differences in laterality for the spreading-of-attention activity were observed only in the simultaneous condition, and only during the early phases of that activity. B, Mean amplitude values over the left and right frontocentral ROIs (for right and left visual stimuli, respectively) for the spreading-of-attention activity for the centrally presented tones in the simultaneous condition, shown separately for when the associated attended visual stimulus was on the left or on the right. The plot underscores the interaction between attention and laterality observed for this initial attentional-spreading activity in the simultaneous condition, which was the only condition for which this early contralaterality effect was significantly present.