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Fig. 4. The dramatic post-pause reduction in the size of electrically elicited
novelty responses is not an aftereffect of a pause-eliciting electrical
`shock'. Post-pause efficiency,
(100), was determined 100 electric organ
discharges (EODs) after a pause. The stimulus used was an electrical pulse
(one cycle of a 1 kHz sinewave, peak-to-peak field strength 235 mV
cm-1). Pausing was elicited either by electrical shocks
(`Electrical'; fish gc1, dark grey columns, 18 pauses; fish gc2, light grey
columns, 10 pauses; fish gc3, black columns, 15 pauses) or, after appropriate
training of the fish, by gently tapping on the wall of the tank (`Mechanical';
12, 10 and 15 pauses, respectively). Values are means + S.E.M.