Second-order conditioning of the pigeon’s keypeck

Abstract

Pigeons learned to peck a keylight (82) when it was paired with a stimulus (81l that already evoked keypecking. Control procedures showed that 82 acquired control over responding because it was paired with 81 and because 81 had a conditioning history , thereby supporting the claim that 82 was a second-order conditioned stimulus. Second-order conditioning occurred as rapidly when 81 was a keylight as when it was a tone. Test procedures showed that after second-order conditioning, responding to 82 was markedly debilitated by the extinction of responding to 81, indicating that the ability of 82 to evoke a response importantly depends upon the continued ability of 81 to do so. Our demonstration that directed motor action in the pigeon is susceptible to second-order conditioning suggests a new interpretation of conditioned reinforcement in instrumental learning. Our dernonstration that the effectiveness of 82 depends upon the continued effectiveness of 81 indicates that 8-8 associations are formed in this version of the second-order conditioning experiment.In conditioning the alimentary and defensive reflexes of dogs, Pavlov noted that distinctive secretory and motor components of each reflex were evoked by the conditioned stimulus (Pavlov, 1927, Lecture Il). He emphasized the secretory component because it was more susceptible to accurate measurement and less susceptible to anthropomorphic interpretation. In recent years, the discovery of autoshaping (Brown & Jenkins, 1968) has focused attention on directed motor responses evoked by classically conditioned stimuli, and automated measurement has attenuated the difficulties Pavlov enumerated in studying motor behavior. In a typical autoshaping experiment, hungry pigeons approach and contact a localized stimulus such as a Iighted response key which signals presentations of food. There seems little doubt that this directed motor behavior provides a behavioral index of the associative status of the localized stimulus (Hearst & Jenkins, 1974) and, consequently, autoshaping provides a new experimental methodology for examining some old questions about associative learning.Autoshaping has been demonstrated with the method of first-order classical conditioning in which a neutral stimulus (SI) acquires control over 25 approach and contact responses because it signals a biologically significant event such as food or water. The first experiment in the present paper dernonstrates that the pigeon's keypeck can be autoshaped with the method of second-order conditioning in which a neutral stimulus (S2) acquires control over keypecking solely because it signals presentations of SI, a first-order conditioned stimulus (cf. Pavlov, 1927, Lecture III). This demonstration is important because it extends the empirical base of secondorder conditioning to include directed motor action, it implicates classical conditioning in the control of directed motor behavior in a wider range of situations than has been acknowledged (Hearst & Jenkins, 1974;Moore, 1973), and because it offers a new o...

Directly reactivated, but not indirectly reactivated, memories undergo reconsolidation in the amygdala

“…Conversely, if responding to CS2 decreases with CS1 extinction (25)(26)(27)(28), the stimuli are believed to constitute an associative chain CS2 3 CS1 3 US. Thus, that in our protocol CS2's ability to produce freezing was compromised by extinction of freezing to CS1 (Fig.…”

“…Thus, the acquisition by CS2 of the ability to control freezing depends on the existing CS1-US association. However, under certain circumstances (e.g., when the two CSs are of the same stimulus modality or are presented simultaneously during second-order training) (25)(26)(27)(28), the CS1 and its relation to the US determines the ability of CS2 to elicit conditioned responses. When this occurs, it is believed that a CS2-CS1 (second-order) association is formed.…”

“…When this occurs, it is believed that a CS2-CS1 (second-order) association is formed. The secondand first-order associations (CS2-CS1 and CS1-US, respectively) are then linked together in an associative network (CS2 3 CS1 3 US) (23)(24)(25)(26)(27)(28). Such associative networks are traditionally viewed as consisting of internal representations of the stimuli and associations between the representations (23,24).…”

Lesions of the Basolateral Amygdala Disrupt Selective Aspects of Reinforcer Representation in Rats

“…There are three proposed mechanisms for the acquisition of responding in second-order conditioning. First, animals may form associations between CS 2 and CS 1 , which, by virtue of an associative chain and existing CS 1 -reward associations, will produce responding during CS 2 (S-S learning, Rashotte et al, 1977;Rescorla, 1979Rescorla, , 1980Rescorla, , 1982. Second, animals may form S-R associations between CS 2 and any response evoked by CS 1 , increasing responding during CS 2 (S-R learning, Rizley and Rescorla, 1972;Holland and Rescorla, 1975).…”

Operant aversive control and Pavlovian higher order conditioning

“…The present results imply a type of Pavlovian higher order conditioning rather than any form of autoshaping. Stimulus generalization is not a plausible alternative explanation given the large amount of data showing that pigeons readily discriminate between green and yellow, Rashotte, Griffin, and Sisk's (1977) fmding that pecking transferred to a signal even when the signal and the signaled events involved different sensory modalities, and the fact that avoidance during the warning signal took some time to develop. The latter would seem to be particularly compelling.…”