Fig. 5: Median response time-split analysis.
From: Attention expedites target selection by prioritizing the neural processing of distractor features
a Difference waveforms for the PC (black) and DC (gray) replotted together from Fig. 3b, c for better comparison. Rectangles indicate previously determined early and late time ranges of significant experimental variation. Median split into fast (b) and slow (c) response times (RT) for DC (gray) and PC (black). ERPs: fast and slow minus non-target difference waveforms averaged across participants (n = 22). Stars indicate significant mean amplitude modulations in the early and late time ranges (p < 0.05). An explorative sample-by-sample sliding t-test (0–100 ms, 11.8-ms window) found no effect for fast PC trials within or before the early time window. Bar graphs: mean GFBA amplitudes of the early and late time range are shown for fast (b) and slow (c) responses. For DC, the early negativity was higher when participants responded fast compared to slow, which was inversely correlated to the size of the late bias (significant early/late GFBA amplitude × fast/slow RT interaction, p = 0.00035, see text for details). For the PC, in contrast, there was no significant difference in GFBA amplitudes between fast and slow responses but always a strong late bias. The error bars represent the standard error of the mean (SEM). Black and gray dots represent data points of individual participants. d 3D current source-density map for the early DC biasing (fast RT trials minus slow RT trials) between 70 and 95 ms (25-ms average). As can be seen, differences in source activity for fast and slow DC trials emerge in posterior extrastriate visual cortex (around V3).
