not notice the differences of intensity of lights effects the availability of food at the beginning, but he remembered he had S- trial in the previous session and stopped pecking. That is why the number of pecking did not exceed 25. According to Sargisson and White (2001), the delay interval plays an important role in the efficiency of learning. The longer the delay interval, more chance of forgetting arise. Although their experiment was not a discrimination training, the connection should exist. The ITI was 10 seconds for all sessions of the discrimination training. The interesting point was as follows. In the second and third sessions, the bird, 4557 achieved several 0 pecking in S- trials, but each of those trials was always in between the S+ trials. If two or more S- trials continued, he had always pecked several times during those S- trials. In other words, he never consecutively achieved 0 pecking. It might explain that he forgot what he learned or at least confused during the consecutive S- trials which means that he had quite long time for refraining of pecking. Because S- trials lasted 30 seconds and the interval time between the trials was 10 seconds, he had to refrain pecking for 90 seconds or more if two S- trials were consecutively given. It strongly tested if he really learned or not. In short, he certainly discriminated the differences of the intensity of key lights, but the forgetting or confusion might have occurred.In one of S- trial, he pecked 31 times, however this trial was in between the S- trials he pecked only 1 or 2 times. Thus, the reason why he pecked so many might be explained as a typeTerror in signal detection theory which inevitably occurs sometimes. And also, he was so hungry that it might have been an expression of his irritation. Do the warm-blooded animals have the feeling of irritation? Further researches are needed for that question, but the bird, 4557*s sudden intense pecking during S- trials in th...
