Detection, reaction, escape, and debilitation thresholds for electric shock in goldfish

Abstract

Reception of electric shock by small goldfish was studied with psychophysical methods. Shock intensity was specified as the gradient in volts/centimeter between the shock electrodes. Changes in current density in the water due to resistance changes had negligible effects upon several measures of reaction to shock. Absolute thresholds for an observable motor reaction were higher with the fish parallel to the electrodes than with a perpendicular orientation. These reaction thresholds were essentially identical to detection thresholds determined in an instrumental avoidance situation. Escape thresholds were substantially higher than reaction and detection thresholds. Changes in shock duration had little effect on any of these thresholds. There was a fairly wide range of motivationally significant shock intensities. Exposure to strong shock did not seem to have any long-lasting effects.