Figure 1
From: Properties of echoic memory revealed by auditory-evoked magnetic fields

Grand-averaged waveforms of auditory-evoked cortical activity. Waveforms in response to the Left-delay sound (L) and Right-delay sound (R) are shown in the upper and lower panels, respectively. For each sound and hemisphere, there were five conditions, 1D, 2D, 3D, 1S, and 2S, which indicate how many different (D) or same (S) sounds preceded the probe sound.