In the next set of analyses, we examined how frequency band-specific phases might be modulated by reaction time, luminance, and their interaction. This is different from cross-trial phase coherence (plotted in Figures 2B,D) because this analysis tests the reliability of the relationship between phase angles and reaction time across trials, rather than the consistency of phase angles across trials. As seen in Figure 5, there was a robust main effect of reaction time in the pre-response theta range in all conditions. Similar to the effects observed in the power regressions, there was an interaction between current and previous conflict (at FCz: F1,14 = 6.56, p = 0.023) which was driven by significantly larger coefficients in cI compared to cC trials (t14 = 5.36, p < 0.001), and no significant difference between iI and iC trials (t14 = 0.66, p = 0.516). There were no significant effects of luminance or reaction time–luminance interaction.
