Fig. 2. Even strong electrosensory stimuli failed to elicit novelty responses when given directly after a pause in the electric organ discharge (EOD). The stimulus was a single cycle of a 1 kHz sine wave delivered far above threshold at a peak-to-peak field strength of 235 mV cm^-1. Each row illustrates the two responses obtained, first when the stimulus was given at the nth post-pause EOD (left traces; n=50, 100, 1000, top to bottom row) and, second, 10 000 EODs later during steady firing (right traces). Stimulus timing is indicated by arrows. Pause durations were 3.9, 16 and 17 s (top to bottom).