Fig 1.
A. Schematic representation of the experimental setup and the recording system. B. Photo of a real experiment (the black background was made darker by image manipulation to show the shot better).
Fig 2.
Fish show a variety of natural preferences.
A. Example of sequence of stimuli presented during the determination of natural preference. B. Natural preference for shapes: percentage of choices for each target for the whole experiment. C. Stability of natural preference: average natural preference for the first and second half of the experiment. The dashed line represents the chance level (33%).
Table 1.
Summary of fish participating in different experiments.
Ext. stands for “extinction”. The + sign indicates that the fish took part in the experiment.
Fig 3.
Fish are capable of learning and unlearning.
A. Success rate for each fish during the learning experiment, with normalized axis for days; the inset shows the same results without normalization. B. Average rate of correct shots during learning on the first and last days. C. Failure rate for each fish during the extinction experiment, with normalized time; the inset shows the same results without normalization. D. Average rate of misses during extinction on the first and last days. The dashed line represents the chance level (50%).
Fig 4.
Fish can learn to associate value and shape.
A. Success rate for each fish on the 1 versus 3 experiment over normalized time; inset: average success rate on the first and last day. B. Success rate for each fish on the 2 versus 4 experiment over normalized time; inset: average success rate on the first and last day. C. Success rate for each fish on the 3 versus 4 experiment over normalized time; inset: average success rate on the first and last day. The dashed line represents the chance level (50%).
Fig 5.
Fish can associate three values and with three shapes.
A. Success rate for each fish on the 1, 2, 3 experiment over normalized time. Inset: average success rate on the first and last day. The dashed line represents the chance level (45.83%). B. Success rate for the three combinations with two targets. The dashed line represents the chance level (50%). C. Success rate for the combination with three targets presented simultaneously. The dashed line represents the chance level (33%).
Fig 6.
Some fish are able to organize shapes according to the value associated with them.
A. Details of the experiment with three shapes for the pairs comparisons for Fish 4. B. Details of the experiment with three shapes for the pairs comparisons for fish 11. C. Details of the experiment with three shapes for the pairs comparisons for fish 12.
Fig 7.
Ratio effect and fish reaction.
A. Effect of value ratio over success rate; the values represent the average over the last three days of the experiment. The error bars represent the standard error. The linear regression is depicted in red. B. Effect of value ratio over reaction time.