Visual discrimination learning in zebrafish (Danio rerio).
Three experiments demonstrated visual discrimination learning in zebrafish (Danio rerio). In each experiment, zebrafish were given a choice between two visually distinct arms of a T-maze. Choice of one stimulus was always followed by a food reward, but choice of the other stimulus was not rewarded. Different colored sleeves fitted around the arms of the T-maze were used in Experiments 1 (green and purple) and 2 (red and blue). The stimuli used in Experiment 3 were white sleeves lined with horizontal or vertical black stripes. In all three experiments, zebrafish acquired a significant preference for the stimulus that led to a food reward. Experiments 1 and 2 also showed that zebrafish could learn a reversal of the discrimination. Finally, the effect of discontinuing food rewards was examined after reversal training in Experiment 2 and after initial discrimination training in Experiments 1 and 3. Non-reinforcement led to a decrease in correct responding in Experiments 2 and 3 independent of stimulus identity, but to an asymmetrical pattern of responding in Experiment 1. The median latency to make a choice response decreased over the course of acquisition in all three experiments; during extinction, median response times did not change at all in Experiment 1 and increased only very slightly in Experiment 2, but showed a substantial increase in Experiment 3. The implications of these results for the zebrafish as a model system for genetic studies of learning and memory are discussed.
Colwill
Ruth M
RM
Department of Psychology, Box 1853, Brown University, Providence, RI 02912, USA. ruth_colwill@brown.edu
Raymond
Maria P
MP
Ferreira
Lisa
L
Escudero
Holly
H
D000818:Animals; D001522:Behavior, Animal; D002755:Choice Behavior; D004193:Discrimination Learning; D005108:Extinction, Psychological; D008568:Memory; D012201:Reward; D014796:Visual Perception; D015027:Zebrafish