each, and the reinforcement schedule was set up during S+ trials. 5 ratios were presented for each S+ trial as random without replacement.The third session was exactly the same as the second session of discrimination training except that the stimulus control tests were given. In the stimulus control tests, S+ period was given in exactly the same way S- periods were given. That is, the S+ period lasted for 30 seconds with no food, and the number of pecks were counted.Note that the number of S- trials for two birds in the first session and one bird in the second session were less than 30 or 15.ResultsOverall, the results of memory test were successful. Only one bird pecked on the dark key many times, but the others did not peck so many. It means that most birds could successfully remembered that the pecking on the dark key did not produce the feeder, and they could get food when the red key was illuminated.In the first session of the discrimination training, the range of the mean number of pecks during S- trials for all birds was from 37 to 65. In the second session, it was from 8 to 73. One bird showed drastic reduction of the sum number of the pecks during S- trials. Although, the number of pecks of the bird, 4341 slightly increased, that bird had no previous training in discrimination between pecking keys illuminated with one or two red lights. Thus, the overall results clearly showed that most birds performed better. That is, they began to realize that the pecking on two red light-key did not produce the feeder.In the third session, some birds performed better, and some other birds showed slightly worse performances. The number of pecks during the stimulus control test (S+ test) for all birds were higher than the number of pecks for S- trials. Then, the discrimination ratio of all birds was higher than 0.5.The bird, 4557 performed very well. In the memory test, after 5th trial out of 30, he did not peck on the dark key at all. In all...
