Lack of instrumental conditioning with intragastric reinforcement in normal experimental procedure

The subject of this study was to check whether it would be possible to establish the alimentary instrumental reflex with direct intragastric reinforcement in normal experimental procedure. The experiment was carried out on ten male albino rats. Seven animals which were permanently implanted with intragastric tube constituted the experimental group. The remaining three rats served as controls. On the basis of obtained results we conclude the following: (i) in normal experimental procedure of conditioning it is impossible to establish a conditioned instrumental response with intragastric reinforcements, at least when the reinforcement amount is 0.5 ml; (ii) instrumental responses with intragastric reinforcement can be obtained using the method of transfer from reflexes with oral reinforcement.