Figure 4.

Effects of auditory attention on ERPs to the left-ear and right-ear syllables illustrated by difference waveforms at the Cz electrode. The difference waves were obtained by subtracting grand-average ERPs to the left-ear standard syllables during right-ear phonological and non-phonological tasks from grand-average ERPs to the left-ear standard syllables during left-ear phonological and non-phonological tasks, respectively, and by subtracting ERPs to the right-ear standard syllables during left-ear phonological and non-phonological tasks from ERPs to the right-ear standard syllables during right-ear phonological and non-phonological tasks, respectively (for the grand-average ERPs, see Figure 3A, top row). Maps on the right show scalp distributions for the early negative-difference (Nd) effect (150–200 ms from syllable onset) and late Nd effect (300–700 ms from syllable onset) determined after measuring, in each participant, the mean Nd amplitude at each electrode over these time windows marked in the difference waves.