Spatially located visual CS effects in conditioned avoidance shuttle response acquisition in goldfish: Conditioned aversion or phototaxis?

Abstract

Goldfish (Carassius auratus) were trained in a conditioned avoidance shuttle response (CASR) situation, where the CS was a color change which occurred on the same, opposite, or both ends of the shuttle tank. One hundred acquisition trials were administered either in a single day or in 20 trials a day for 5 consecutive days. Earlier work, using a change of illumination level CS, found different CASR acquisition rates with 1 day of training vs. training over several days. The present study finds basically the same order of acquisition rates within a single day as over days, with the exception of one group. Differences between CS location acquisition rates in earlier work (with illumination level change) and those of the present study (color change without illumination level change) are explained on the basis of negative phototaxis or confusion reactions occurring under the illumination level change situation.