Contrast between random and blocked conditions within the 434–552 ms period computed after parametric statistics (t-test, P < 0.01, with FDR correction). The color-coded map indicates the direction and magnitude of differences in neural activity, measured in picoamperes times meters (pA.M). Purple represents areas where there was a significantly more positive electrical potential (higher pA.M values) in the random condition than in the blocked condition. Conversely, blue denotes areas showing significantly more negative electrical potentials in the random condition relative to the blocked condition.