Discriminative Training on Two Different Luminance of Key Lights
Not a few experiments on the discriminative training with pigeons were done over past several decades, and many researchers found that various factors relate to the results of discriminative training with pigeons. In a classical study by Heinemann and Rudolph (1963), they suggested that the geometric size of the stimulus influences on the efficiency of the learning by pigeons. There are several other factors pertaining to that efficiency of the learning. According to Sargisson and White (2001), the training delay is one of those factors. They found that the longer the training delay, the more sessions were required for all birds to reach the same level of response accuracy (Sargisson & White, 2001).
In this discriminative training, therefore, the ring doves were trained with several different conditions in order to obtain some suggestions for to understand how they learn and what factors relates to the efficiency of their learning. What the doves learned in this operant conditioning was the discrimination of two different luminance of key-lights. Because many researches found that the doves had the reliable ability for discrimination of the intensity of lights, the results of learning depends on the long term memory of the subjects.
Summarily, the purpose of this training was to know whether the doves can discriminate the differences of luminance of lights, and the factors which influences on their learning.
Seven hungry ring doves (Streptopelia risoria) were tested. Six of them had previous experience on training to discriminate between the two red lights which had different luminosity. Before that, all of the doves were autoshaped to peck at a red key illuminated by one red bulb. Two of them have participated in many experiments for 14 years.
Testing was conducted in a student chamber (37 cm wide × 29 cm deep × 23 cm high) designed by Lehigh Valley. The side of the chamber was clear plastic board to see the reaction of the doves. Stimuli were the light produced by one or two red bulbs. The each bulb had approximately 120 cd/㎡of luminosity. The light produced by two bulbs had approximately 240 cd/㎡of luminosity. The size of stimuli was the circular switch which was approximately 2 cm in diameter. It was presented at the point of where 7 cm from the floor. The reinforcement was 2 seconds in the discrimination training. The food was mixed grains.
The seven chambers were located in the different sound attenuated cubicles. The chambers were operated not by computers but the hands of students. The number of pecks on the key-lights with sufficient force was automatically counted by the machine connected to the chamber. That machine controlled the luminosity of red lights. Basically, pecking the switch with one red light delivered reinforcements (opportunities to eat mixed grains for 2 seconds) to the subjects . No punishment was...