Abstract: 1. Biogenic amines are injected directly into the bee brain in the region of the thick ocellar neurones, and their effects are studied using the proboscis conditioning paradigm. 2. Responsiveness to unconditioned olfactory stimuli is enhanced by the phenolamine octopamine, but is not modified by the monoamines dopamine and serotonin. 3. Dopamine and serotonin reduce the percentage of bees responding to a conditioned stimulus. The reduction occurs regardless of whether the amine is injected before or after single trial conditioning. 4. The effects of dopamine are time dependent. After 60 min, responses initially reduced by dopamine, return to a level similar to that observed in control groups treated with Ringer solution. 5. Dopamine does not effect the storage processes involved in learning, but inhibits information retrieval. The effects of serotonin are similar to, but less potent than those of dopamine. Octopamine has no negative influence on storage or retrieval of information, but enhances responsiveness to olfactory stimuli.

Abstract: Publisher Summary This chapter describes the ways in which Pavlovian conditioning operates in a number of biological contexts The chapter suggests that Pavlovian conditioning may transform some of the environment's capriciousness, and that the Pavlovian conditional response plays an important role in optimizing interactions with biologically important events Through selected animal learning and animal behavior experiments the chapter highlights the ways in which an animal might incorporate a signaling operation in the various aspects of its search for food, including (1) locomotory search and approach behavior, (2) consummatory and food-procuring behavior, and (3) autonomic behavior related to food ingestion The importance of Pavlovian conditioning in the development of food selection and in the avoidance or consumption of poisons is also discussed The chapter reviews the evidence for conditioned interspecific and intraspecific defensive behavior and shows the adaptive value of prefiguring It reveals that the prefiguring hypothesis is able to make novel predictions about conditioned behavior and provides a systematic account of the many different “response rules” governing the form, the appearance, and the timing of the Pavlovian conditional response

Abstract: These experiments document a form of early appetitive learning in rats obtained using classical conditioning procedures. Some of the special determinants of this conditioning are described, as well as ontogenetic changes in the effectiveness of training procedures. Learning was apparent when deprived 3- and 6-day old rats oriented to and maintained contact with a novel and normally aversive odor after this odor had been paired with oral infusions of milk (Experiment I). The effectiveness of the conditioning procedures depended on the temperature at which pups were trained (Experiment IB). Moreover, the reinforcing properties of milk infusions depended on deprivation (Experiment IC). This conditioned change in responsiveness to odor was specific to the odor that had been paired with milk (Experiment II) and was retained for at least 24 hr (Experiment III).

Abstract: Two investigators independently rated 51 white, male prison inmates on a 7-point psychopathy scale (interrater reliability = .89). The combined ratings were used to divide the inmates into low (1), medium (M). and high (H) psychopathy groups of 17 subjects each. Following a sample trial, each inmate was given two trials in which he could choose how to spend his time during a 5–6 min wait for an aversive stimulus (120dB tone). Three choices were available: 1) continuous white noise, 2) a recording of a nightclub comedian, or 3) a continuous tone that changed in frequency 10 sec before delivery of the aversive stimulus. The aversive stimulus could be avoided on one trial but not on I he other (the order was counterbalanced). When the aversive stimulus was unavoidable (Trial UA), 46 (90.2%) of the inmates spent all or most of their time listening to the comedian, i.e., they adopted a “nonvigilant” strategy, while 38 (74.5%) adopted this strategy when the aversive stimulus was avoidable (Trial A). There were no group differences in the type of strategy used on either trial, or in the physiological responses given by the nonvigilant subjects on Trial UA. Group H tended to give smaller electrodermal responses and a larger increase in HR in anticipation of the sample tone than did Group L, a pattern that is consistent with previous research using classical conditioning or “count down” procedures. On Trial A the nonvigilant subjects in Group H showed a significantly smaller increase in nonspecific skin conductance activity than did Group L. It is suggested that making use of distraction when an aversive stimulus is avoidable results in less conflict and heightened emotional arousal in psychopaths than in other inmates. Some speculations on how psychopaths cope with threat are offered.

Abstract: In each of two experiments, allocation of cognitive processing capacity was measured in college-student subjects during autonomic discrimination classical conditioning. A 7.0-sec delay paradigm was used to establish classically conditioned responses to a reinforced visual conditioned stimulus (CS+). Electrodermal responses were the primary measures of autonomic classical conditioning. Allocation of processing capacity was measured by monitoring performance on a secondary reaction-time (RT) task. The auditory secondary-task RT signal was presented before, and 300, 500, 3500, 6500, and 7500 msec following CS onset. The RT signal was also presented following properly and improperly cued shock unconditioned stimuli (UCSs). Significant discrimination classical conditioning was obtained in both experiments. Comparison with control subjects who did not receive the RT signals indicated that the presence of the RT signals did not interfere with the development of classical conditioning. Four principal findings were obtained with the secondary-task RT measure. First, RTs to signals presented during CS+ were consistently slower than RTs to signals presented during CS-. This finding indicates that greater capacity allocation occurred during CS+ than CS- and is consistent with recent cognitive interpretations of classical conditioning. Second, the largest capacity allocation (i.e., slowing of RTs) occurred 300 msec following CS+ onset. This finding is consistent with the notion that subjects are actively processing the signal properties of the CS+ at 300 msec following CS+ onset. Third, presentation of the UCS when improperly cued (following CS-) significantly increased capacity allocation, whereas presentation of the same UCS when properly cued (following CS+) did not affect capacity allocation. These findings indicate that subjects were actively prepared for the UCS following CS+ but not following CS- and that a surprising UCS elicits greater capacity allocation than does an expected UCS. Fourth, large electrodermal responders to the CSs exhibited patterns of capacity allocation during the CSs, particularly during the CS+, different from those of small electrodermal responders. In particular, they exhibited significantly longer RTs at 300 msec after CS+ onset than did the small responders, followed by a shortening of RT at 500 msec relative to the small responders. This finding suggests that large electrodermal responders devote greater processing capacity to significant environmental stimuli than do small responders and that their processing may begin and be completed more rapidly. All in all, the data indicate the complexity of the cognitive processes that occur during human classical conditioning and the usefulness of the secondary-task technique in integrating conditioning theories and psychophysiology with cognitive psychology.

Abstract: Potentiation of odor by taste in rats was tested in a variety of situations. In three experiments, almond odor and saccharin taste were presented either as a single conditioned stimulus (CS) or as a compound CS and followed by either toxic lithium chloride or footshock. Extinction tests with the almond and saccharin components were then given. In single CS-toxin experiments, taste was more effective than odor, and after compound conditioning, the taste component potentiated the odor component. Conversely, in single CS-shock experiments, odor was more effective than taste, and after compound conditioning, no potentiation was observed. Rather, interference effects were observed. In Experiments 1 and 2, the addition of taste disrupted odor CS-shock conditioning, and in Experiment 3, odor interfered with taste CS-shock conditioning. Visceral feedback is apparently a necessary unconditioned stimulus for the potentiation of odor by taste. These data support the neural convergence and gating hypothesis of flavor aversion conditioning.

Abstract: The goal of this review is to compare two divergent lines of research on signal-centered behavior: the orienting reflex (OR) and autoshaping. A review of conditioning experiments in animals and humans suggests that the novelty hypothesis of the OR is no longer tenable. Only stimuli that represent biological "relevance" elicit ORs. A stimulus may be relevant a priori (i.e., unconditioned) or as a result of conditioning. Exposure to a conditioned stimulus (CS) that predicts a positive reinforcer causes the animal to orient to it throughout conditioning. Within the CS-US interval, the initial CS-directed orienting response is followed by US-directed tendencies. Experimental evidence is shown that the development and maintenance of the conditioned OR occur in a similar fashion both in response-independent (classical) and response-dependent (instrumental) paradigms. It is proposed that the conditioned OR and the signal-directed autoshaped response are identical. Signals predicting aversive events repel the subject from the source of the CS. It is suggested that the function of the CS is not only to signal the probability of US occurrence, but also to serve as a spatial cue to guide the animal in the environment.

Abstract: Four experiments explored the consequences of simultaneous second-order conditioning of one stimulus (S2) by another (S1) in a conditioned suppression preparation. In two experiments, that mode of presentation produced second-order conditioning of S2 which was attenuated by subsequent extinction of S1. Sequential presentation of the same stimuli produced similar levels of conditioning of S2 which were not affected by extinction of S1, results that replicate previous findings. Two additional experiments found tht the sensitivity of a simultaneous S2 to changes in S1 also depended on that S1 receiving few separate reinforced or nonreinforced presentations prior to second-order conditioning . The results suggest circumstances under which the typical stimulus-response learning observed in second-order conditioned suppression can be converted into stimulus-response learning. An interpretation is suggested in terms of simultaneous presentation generating a unitary representation involving both S2 and S1 rather than an association between them.

Abstract: Three experiments are reported which use rats and the conditioned suppression technique. The first two confirmed a previous finding that prior exposure to a stimulus predicting a weak shock retards further learning when this same stimulus is subsequently used to signal a stronger shock. They further showed that this loss of stimulus associability could be attenuated by inserting trials on which the stimulus was presented alone in the absence of shock before the phase of training with the stronger shock. Experiment III demonstrated that, for animals given prior exposure to two stimuli, the insertion of nonreinforced trials with one of the stimuli will restore the associability only of that stimulus. These results are taken to show that a surprising event (the omission of an expected shock) can restore the associability of a pre-exposed conditioned stimulus.

Abstract: The effects of compounding two conditioned stimuli (CSs), each of which had been extinguished to varying degrees in different groups of rats given identical acquisition training, was examined within the conditioned emotional response paradigm. Greater suppression to the compound than to the individual CSs was observed following 6, 12, 48, 72, and 96 stimulus extinction trials, although after only 12 extinction trials suppression to the individual stimuli was no longer observed. The amount of compound suppression decreased progressively as the number of extinction trials increased until, after 120 extinction trials on each stimulus, the compound no longer elicited observable suppression. Control group data indicated that the observed summation effect could not be attributed to disinhibition. The possible role of the summation of undetected excitation in studies examining configurai conditioning, avoidance conditioning and reinstatement is discussed briefly.

Abstract: An experiment with rats has demonstrated that Pavlovian conditioning factors determine the occurrence of tolerance to haloperidol catalepsy. Rats exhibited tolerance only in the environment previously associated with the drug. Previous research involving receptor binding techniques implicated an increase in the number of brain dopamine receptors as the mediator of neuroleptic tolerance. The present findings demonstrate that this change, by itself, cannot account for the conditional occurrence of such tolerance.

Abstract: Three experiments examine transfer from appetitive Pavlovian conditioning to appetitive instrumental responding by varying the similarity between conditions of Pavlovian reinforcement and instrumental reward After conditioning with rats confined in a restraining device, a CS for electrical stimulation of the brain (ESB) produced substantial facilitation of operant responding for ESB, while a CS for food facilitated operant responding for food However, no effects on rate of responding for food were seen during a CS for ESB In a fourth experiment, four groups of rats were trained to barpress for rewarding electrical stimulation of the brain (ESB) and then given discriminative Pavlovian conditioning with ESB The groups differed in the degree of similarity between the stimulus-response sequences present during Pavlovian conditioning and those occurring in instrumental responding As similarity increased, so did the degree of conditioned facilitation in subsequent transfer tests These results indicate that conditioned incentive responses or reinforcer-derived expectancies are specific to the conditions under which they develop, rather than generalized emotional or motivational responses

Abstract: Two experiments were conducted to investigate functional similarities between “hunger CRs” of Konorski’s (1967) model of appetitive classical conditioning and sign-tracking behavior in rats. Konorski’s model predicts that hunger CRs will be facilitated (1) when a nonrein-forced stimulus similar to the reinforced CS is introduced, and (2) when some CS presentations are unexpectedly nonreinforced. In Experiment 1, hungry rats acquired a leverpress response to a retractable lever that was paired with response-independent food. Following this training, a second lever was introduced whose presentation was not followed by food. The effect of the presence of this second lever was to facilitate responding to the original lever. In Experiment 2, single-lever autoshaping training was followed by a shift from 100% pairing of the lever with food to only 50% of the lever presentations being followed by food. The introduction of partial reinforcement produced an immediate and durable increase in leverpressing. The findings of both experiments are consistent with predictions from Konorski’s model of classical conditioning if sign-tracking is considered as a “hunger CR.”

Abstract: Three theories of classical conditioning were examined with regard to the earliest conditioning trial on which blocking could first occur. One theory (Rescorla & Wagner, 1972) predicts the occurrence of blocking on the first compound trial, whereas the other two (Mackintosh, 1975b; Pearce & Hall, 1980) predict that blocking will not occur until after the first compound trial. Using conditioned suppression of licking in water-deprived rats as a measure of associative strength, we found that substantial blocking of tone-footshock (X-US) associations occurred when a single light plus tone-footshock (AX-US) pairing followed 12 A-US pairings. The results are discussed in light of previous attempts to obtain one-trial blocking, and the implications of all of these studies for classical conditioning theory are considered.

Abstract: Four experiments using rats were conducted to determine whether a "counterconditioning" procedure would be effective in altering old, but reactivated, memory. The aversiveness of previously established Pavlovian conditioned stimuli was reduced by giving subjects a highly preferred substance (maltose solution) shortly after a brief exposure to the fear cues (Experiments 1 and 2). No evidence of a time-dependent effect was obtained with a 1-hr. delay between reactivation and maltose (Experiment 2). Groups given noncontingent footshocks in lieu of Pavlovian conditioning (whether or not they subsequently received maltose) showed uniformly little aversion to test cues (Experiment 3). This finding suggests that counterconditioning in this paradigm affects associative memory processes. A time-dependent effect of delayed treatment and other evidence that active memory is necessary for counterconditioning were obtained (Experiment 4). These experiments support the notion that in rats as well as in humans, memory is a malleable process susceptible to postacquisition modifications and revealed the potential value of the reactivation paradigm in studying counterconditioning as a model for desensitization.

Abstract: Blocking of conditioned suppression in rats was studied in three experiments using serial and simultaneous compounds in Pavlovian trace conditioning procedures. Experimental groups were first given trace conditioning trials with a 2-sec stimulus (A) presented at least 60 sec before an electric grid shock US. Next, both experimental and control groups received reinforced trials with a compound stimulus (AB). Both A and B were 2 sec in duration and were presented at least 60 sec before the US. For some groups during AB training, the A stimulus preceded the B stimulus; for others, B preceded A; for still others, A and B occurred simultaneously. Conditioning was subsequently assessed separately to both A and B. The results were as follows: First, varying the interval between the onset of A and the US during A training appeared to produce significantly different levels of conditioning to A but did not detectably affect A’s ability to block conditioning to B. Second, blocking was observed in both simultaneous and serial procedures. Third, in the serial procedure, A blocked conditioning to B whether it preceded B or followed B in the AB compound. Fourth, in tests given after AB conditioning, the experimental and control groups suppressed similarly to A. The relevance of these results to the conditioning model of Rescorla and Wagner (1972) and to Mackintosh’s (1975b) theory of attention are discussed.

Abstract: The purpose of this experiment was to test the theory of Lubow, Rifkin, and Alek (1976) concerning the effects of stimulus preexposure on later learning. This hypothesis predicts that conditioning will occur faster when either the stimulus or the testing environment is novel relative to the other than when the stimulus and the environment are equally novel or equally familiar. The theory was tested in a taste aversion conditioning paradigm in which groups of rats were presented with either the familiar (preexposed) solution or the novel nonpreexposed solution, in either the familiar or the novel environment. Conditioning was affected by the novelty of both the stimulus and the environment, with novel stimuli enhancing learning and novel environments retarding it. However, no interaction between stimulus and environmental novelty was evident, and thus Lubow’s hypothesis was not confirmed.

Abstract: In male Betta splendens, aggressive behavior is drastically attenuated following telencephalon ablation. Because instrumental training and Pavlovian conditioning experiments with intact fish have suggested that associative factors may play an important role in the performance of agonistic behaviors, the effect of ablation on instrumental learning and Pavlovian conditioning was studied. In Experiment 1, ablation had no effect on the learning of the instrumental tunnel-swimming response reinforced by mirror presentation (i.e., viewing a conspecific), although the mirror presentations in yoked-control groups elicited fewer responses in ablates than in normal and sham-operated control fish. Yoked controls further established that instrumental responding was maintained by the reinforcement contingency and was not merely the result of increased motor activity. Experiment 2 studied Pavlovian conditioning of the components of the agonistic display. Unconditioned fin erection, gill erection, and tail beating (i.e., unconditioned responses, URs) to the mirror US all were less frequent in ablates than in normals or shams. Of these, only gill cover erection showed evidence of true conditioning (i.e., conditioned responses; CRs) in which responses to the conditioned stimulus (CS) are due to the pairings of CS and US (unconditioned stimulus). However, ablates suffered no impairment of conditioned gill erections. Ablates performed fewer fin erections to the CS; however, fin erection responses were not due to CS-US pairings but were attributable to pseudoconditioning. These results are related to hypotheses postulating the involvement of learning mechanisms in ablation-produced deficits and normal aggressive behavior.

Abstract: Rats received paired injections of either ethanol or saline as the conditioned stimulus and lithium chloride as the unconditioned stimulus (US) in a Pavlovian differential conditioning paradigm. Lithium chloride evoked a large deceleration in heart rate (80-100 beats per minute) as an unconditioned response. As a result of 10 conditioning trials, the substance paired with LiCl elicited a lower average heart rate than that elicited by the unpaired substance. Moreover, animals that received ethanol-LiCl injections subsequently were more averse to the taste of ethanol than animals receiving saline-LiCl pairings. However, there were no differences in ethanol's ability to serve as the US to induce an aversion to a novel flavor solution (i.e., the Avfail phenomenon was not observed). The overall pattern of results underscores the value of using multiple indexes of learning in drug-drug conditioning paradigms.

Abstract: Three experiments were conducted employing a continuous measure of conditional stimulus/unconditional stimulus (CS/US) contingencies as perceived by the subject (i.e., subjective contingency or SC). It is argued that direct measurement of relational learning, as indexed by SC, can lead to a better understanding of Pavlovian conditioning processes. The first two experiments applied this approach to a methodologic controversy, raising the debate from a procedure-based argument to testing what the subject actually learns about CS/US relationships. While the issue was not resolved, testable hypotheses for future research were generated from the data. The third experiment contrasted the contingency stimulus-stimulus (S-S) account of Pavlovian conditioning with an earlier stimulus-response (S-R) continguity-reinforcement account. In this experiment, both SC and skin resistance were measured. Evidence for the existence of both cognitive-propositional and response-learning processes in conditioning was obtained.

Abstract: For the rat, the interaction of food-related cues and the visceral feedback following ingestion largely determines future consummatory behavior. In early work (Garcia & Koelling, 1966), it was shown that taste cues were most readily associated with illness; conditioned taste aversions were formed after only a single taste-illness experience. Unlike most other demonstrations of classical conditioning, the delay between the taste conditioned stimulus (CS) and the illness unconditioned stimulus (US) could be an hour or more and strong taste aversions still would be formed. In contrast to tastes, an audio-visual signal was a poor CS for illness conditioning, acquiring little or no aversive properties following a single toxic US. If footshock was used as a US, the converse obtained. An audio-visual CS was readily associated with footshock US whereas taste was a poor CS in shock avoidance conditioning.