clearly significantp < 0.0001
In addition to our crucial comparison of the two interference effects, the modulation of the load over the benefits observed for the valid condition was clearly significant, χ 2 (1) = 374.11, p < 0.0001; in fact, we observed (see Figure 7 ) a much larger modulation for the benefits (64 ms larger for high compared to low perceptual load), than for the costs (11 ms larger for high perceptual load).