Topographical distributions for Experiments 1 and 2. Scalp maps and selected electrode waveforms demonstrating measured N400 effects of predictability and congruity during the 300–500 ms time-window in Experiments 1 and 2. Scalp maps illustrate the mean difference between low probability and high probability conditions in Experiment 1 (A) and between semantically incongruous and congruous conditions in Experiment 2 (B).