Fear-motivated vicious-circle behavior maintained through secondary punishment     

Kenneth B. Melvin  Thomas K. Irving  Steven Prentice-Dunn 《Learning & behavior》1979,7(2):185-190

Two experiments attempted to establish vicious-circle behavior through fear motivation combined with secondary punishment. In Experiment 1, rats were trained with two CSs, a tone and a buzzer, paired with shock in different contexts. Secondary punishment based on delay and trace conditioning procedures facilitated running in fear-motivated rats, relative to four control groups. In Experiment 2, rats were given pairings of a tone CS with shock, and a buzzer CS with a drop into a water tank. Fear-motivated rats which received secondary punishment during either 33% or 100% of test trials exhibited self-punitive running relative to a nonpunished (0%) group and a backward-conditioning control group. Results indicate that “all secondary” vicious-circle behavior can be established through Pavlovian conditioning, thus supporting a conditioned fear interpretation.  相似文献   

The effects of qualitative and quantitative variation in the US on individual components of Pavlovian appetitive conditioned behavior in rats     

Peter C. Holland 《Learning & behavior》1979,7(4):424-432

The form of rats’ Pavlovian conditioned responses to visual and auditory conditioned stimuli (CSs) paired with a variety of unconditioned stimuli (USs) was examined in three experiments using direct behavioral observation techniques. In Experiment 1, the form of conditioned behavior occurring most frequently during later portions of the CS-US interval depended only on which of several appetitive USs was used, but the form of behavior occurring most frequently during early portions of the CS-US interval depended only on the nature of the CS. US-dependent behaviors resembled the response to the US, and CS-dependent behaviors resembled the original orienting response (OR) to the CS. In Experiment 2, the use of larger magnitude appetitive USs resulted in higher frequencies of US-dependent behaviors, but lower frequencies of CS-dependent behaviors in the presence of auditory and visual CSs. In Experiment 3, US-dependent conditioned behavior to auditory and visual CSs paired with shock was more frequent when high-intensity shocks were used, but CS-dependent behavior was more frequent when low-intensity shocks were used. These results suggested that Pavlovian conditioned responding may involve two independent types of behavior—one appropriate to the US and another based on the original OR to the CS.  相似文献   

Conditioned suppression of a positively reinforced shuttle response     

Julian C. Leslie  Paul Garrud 《Learning & behavior》1976,4(1):99-104

Rats were trained to run up and down an alleyway for sucrose reinforcement on a variable interval schedule. Differential aversive classical conditioning with auditory CSs was then conducted in a separate apparatus (“off the baseline”) prior to those CSs being presented while the subjects were responding for sucrose in the alleyway. Once the effects of the CSs had extinguished, shock was reintroduced following one CS but not the other (“on the baseline” differential aversive classical conditioning). Both “off the baseline” and “on the baseline” conditioning resulted in conditioned suppression to the CS followed by shock, but little effect of the CS followed by no shock was found. In the “on the baseline” phase, total suppression of baseline responding occurred at moderate US intensities, and this appeared to result from the subject avoiding the location at which he was last shocked. At lower values, both baseline response rate and relative suppression ratio were functions of US intensity. The results are discussed in relation to the effects found in similar experiments using avoidance baselines.  相似文献   

Blocking and enhancement of fear conditioning by appetitive CSs     

Joel H. Goodman  Harry Fowler 《Learning & behavior》1983,11(1):75-82

Prior research on Pavlovian-to-instrumental transfer has shown that when a CS previously associated with shock (AvCS+) is presented contingent upon a choice response to a discriminative stimulus for food reinforcement, it facilitates discrimination learning. Conversely, a response-contingent CS previously associated with the absence of shock (AvCS?) retards discrimination learning. To evaluate whether these findings reflect across-reinforcement blocking and enhancement effects, two experiments investigated the effects of appetitively conditioned stimuli on fear conditioning to a novel stimulus that was serially compounded with the appetitive CS during conditioned-emotional-response (CER) training. Although there were no differential effects of the appetitive CSs in CER acquisition, Experiment 1, using a relatively weak shock US, showed that a CS previously associated with food (ApCS+) retarded CER extinction to the novel stimulus, in evidence of enhanced fear conditioning to that stimulus. In addition, Experiment 2, using a stronger shock US, showed that a CS previously associated with the absence of food (ApCS?) facilitated CER extinction to the novel stimulus, in evidence of weaker fear conditioning to that stimulus. These results parallel traditional blocking effects and indicate not only that an ApCS+ and an ApCS? are functionally similar to AvCSs of opposite sign, but that their functional similarity is mediated by common central emotional states.  相似文献   

Pavlovian aversive to instrumental appetitive transfer: Evidence for across-reinforcement blocking effects     

H. Fowler  J. H. Goodman  M. L. Zanich 《Learning & behavior》1977,5(2):129-134

Rats received Pavlovian aversive (shock) conditioning in which white noise was established for different groups as a CS+, CSO, or CS?. Then, in an appetitive T-maze discrimination, the CSs were presented contingent upon a designated correct response for which food reinforcement was factorially varied at 0, 1, 2, or 4 pellets. Although the CS+ suppressed and the CS? facilitated speed of running in the correct arm at the start of discrimination training, these effects extinguished rapidly and did not interact with reward magnitude. Furthermore, choice learning was faciltated by the CS+ and retarded by the CS?, with these effects being comparable for the 1- to 4-pellet reinforcement conditions, but absent for the 0-pellet condition. These findings are difficult to reconcile with a transfer interpretation positing a general signaling property of the CS and are better interpreted as across-reinforcement blocking effects: By predicting a preferred outcome (safety) comparable to the preferred outcome of food reinforcement, the CS? blocks (retards) the association of reinforcement and the S^D; conversely, by predicting a nonpreferred (shock) outcome discrepant from the preferred food outcome, the CS+ “counterblocks” (enhances) the association of reinforcement and the S^D.  相似文献   

Transfer of conditioned suppression and conditioned acceleration from instrumental to consummatory baselines     

Hank Davis  Donald Shattuck 《Learning & behavior》1980,8(2):253-257

Following training on a variable-interval food reinforcement schedule, rats were exposed to Pavlovian procedures which produced reliable conditioned suppression and conditioned acceleration of the leverpressing (instrumental) baseline. When free food was simultaneously made available in the test cage, all subjects spent the majority of each session “freeloading,” that is, eating food from a dish rather than leverpressing for it. When superimposed upon the freeloading baseline, the conditioned suppression and conditioned acceleration procedures affected the rate of pellet consumption identically in magnitude and direction to their previous effects on leverpressing. These results suggest a motivational mechanism for conditioned suppression and acceleration, rather than one which depends upon spurious punishment of specific response sequences.  相似文献   

On the generality of conditioned bradycardia in rabbits: Assessment of CS and US modality     

D. A. Powell  Charles M. Gibbs  Brian Maxwell  Dianne Levine-bryce 《Learning & behavior》1993,21(4):303-313

To determine whether the magnitude of heart rate (HR) slowing induced by classical conditioning contingencies is comparable under a broad range of stimulus conditions, experiments were conducted in which rabbits were exposed to tones, increases in illumination, or vibratory stimuli as conditioned stimuli (CSs) and in which paraorbital electric shocks, corneal airpuffs, or intraoral pulses of water served as unconditioned stimuli (USs). The results indicated that conditioned bradycardia was elicited by all three CSs. Moreover, when a corneal airpuff served as the US, small but reliable CS-evoked HR decelerations also occurred. Finally, CS-evoked HR slowing also occurred in response to a tone CS employed in an appetitive task, in which water was the US. These findings suggest that HR slowing is a general phenomenon that occurs when rabbits are exposed to signals that systematically predict aversive or appetitive consequences according to a Pavlovian conditioning paradigm.  相似文献   

The erasure of reinstated fear     

Robert A. Rescorla  Christopher L. Cunningham 《Learning & behavior》1977,5(4):386-394

Three experiments investigated the reinstatement of fear to a previously conditioned and extinguished CS as a result of separate presentation of the original US. That reinstatement was found to be sharply attenuated by nonreinforcement of a second fear elicitor between presentations of the US and testing of the CS. This “erasure” of reinstatement depended upon the fear-eliciting power of the intervening stimulus and, under some circumstances, was essentially complete. Moreover, erasure reduced not only the response to the CS but also the extinction it underwent as a result of subsequent nonreinforcement. It is argued that neither the conditioning of background stimuli nor stimulus generalization among explicit CSs provides an adequate account of these reinstatement and erasure results. Rather, they are interpreted in terms of the construction and destruction of a nonassociative representation of the US during conditioning, extinction, reinstatement, and erasure. In that context, some inferences can be made about the rules governing these nonassociative changes and the ways in which they interact with modifications in associations.  相似文献   

Temporal integration and instrumental conditioned reinforcement     

Eric A. Thrailkill  Timothy A. Shahan 《Learning & behavior》2014,42(3):201-208

Stimuli associated with primary reinforcement for instrumental behavior are widely believed to acquire the capacity to function as conditioned reinforcers via Pavlovian conditioning. Some Pavlovian conditioning studies suggest that animals learn the important temporal relations between stimuli and integrate such temporal information over separate experiences to form a temporal map. The present experiment examined whether Pavlovian conditioning can establish a positive instrumental conditioned reinforcer through such temporal integration. Two groups of rats received either delay or trace appetitive conditioning in which a neutral stimulus predicted response-independent food deliveries (CS1→US). Both groups then experienced one session of backward second-order conditioning of the training CS1 and a novel CS2 (CS1–CS2 pairing). Finally, the ability of CS2 to function as a conditioned reinforcer for a new instrumental response (leverpressing) was assessed. Consistent with the previous demonstrations of temporal integration in fear conditioning, a CS2 previously trained in a trace-conditioning protocol served as a better instrumental conditioned reinforcer after backward second-order conditioning than did a CS2 previously trained in a delay protocol. These results suggest that an instrumental conditioned reinforcer can be established via temporal integration and raise challenges for existing quantitative accounts of instrumental conditioned reinforcement.  相似文献   

Transfer of contextual control across similarly trained conditioned stimuli     

Dale Swartzentruber 《Learning & behavior》1993,21(1):14-22

Two autoshaping experiments with pigeons examined contextual control of responding to conditioned stimuli (CSs) when separate phases of reinforcement and nonreinforcement occurred in different contexts. In Experiment 1, a CS was first conditioned in Context A prior to nonreinforcement in Context B. In Experiment 2, a conditional discrimination reversal procedure was employed in which one CS was first reinforced in A prior to nonreinforcement in B, and another CS was first nonreinforced in A and then reinforced in B. In both experiments, the extent of contextual control was assessed by testing the CSs in A and B. The CS specificity of control was assessed by examining control of CSs that had been treated like the original CSs, but in a different pair of contexts. The results show that contexts control responding to CSs through a CS-specific mechanism, as well as through a mechanism that is independent of the identity of the CS. However, the extent to which control is mediated by a CS-independent mechanism depends on the training history of the CS.  相似文献   

CS-duration and partial-reinforcement effects counteract overshadowing in select situations     

Urushihara K  Miller RR 《Learning & behavior》2007,35(4):201-213

Two experiments used rats in a conditioned lick suppression preparation to investigate how the conditioned stimulus (CS)-duration and partial-reinforcement effects (i.e., weakened responding due to conditioning with a CS of longer duration and presenting nonreinforced CSs intermingled with CS—unconditioned stimulus [US] pairings, respectively) interact with overshadowing. Experiment 1 found that when overshadowing treatment was combined with either extended CS duration or partial reinforcement, the response deficit was weaker than when either of these three treatments was administered alone. In Experiment 2, the generality of the findings in Experiment 1 was investigated by replicating it with various US—US intervals. This time counteraction was observed only when both the absolute duration of total CS exposure and the US—US interval were short. The results support neither the view that the ratio between the total CS exposure and total time in the context determines the CS-duration and the partial-reinforcement effects nor the view that these two effects arise from a loss of effectiveness of the excitatory CS—US association during CS-alone exposures in partial reinforcement or early periods of CS exposure with long CSs.  相似文献   

Backward conditioning to a CS following an expected vs. a surprising UCS     

Allan R. Wagner  William S. Terry 《Learning & behavior》1975,3(4):370-374

Rabbits were trained in eyelid conditioning with a “backward” arrangement of unconditioned stimulus (UCS) followed by conditioned stimulus (CS). When such a CS was tested alone it was observed to produce substantial conditioned responding if the UCS had been arranged to be “surprising” during the backward pairings, but not if it had been arranged to be “expected.” The comparisons were made in a within-subjects design where the surprisingness of the UCS on the different pairing occasions was manipulated by preceding the UCS by discriminative CSs which were otherwise either never followed by the UCS (CS?) or consistently followed by the UCS (CS+). The results may have implications for the nonmonotonic course of responding seen during backward conditioning, as a UCS is at first surprising, but then expected on the basis of contextual cues.  相似文献   

Fear of the CS and of the context in two-way avoidance learning: Between- and within-subjects manipulations     

Edward J. Callen 《Learning & behavior》1986,14(1):80-89

The roles of CS fear and of context fear in signaled two-way avoidance learning were examined in two experiments in which shock intensity was manipulated either between or within subjects. For each subject, two discrete CSs, a light and a white noise, were used. For between-subjects comparisons, both CSs were paired with the same shock intensity, weak or strong. Under this condition, in which fear of the CSs and the context was greater with strong than with weak shock, avoidance performance varied inversely with shock intensity. For within-subjects comparisons, the light was paired with strong shock and the white noise with weak shock, or vice versa. In this case, context fear was constant during presentation of each CS, and avoidance performance varied directly with shock intensity. Additionally, intertrial responding was directly related to the amount of context fear. These results support effective reinforcement theory, an extension of two-factor theory, which acknowledges the contribution to avoidance learning both of CS fear and of context fear. The interchangeable effectiveness of visual and auditory stimuli as CSs is discussed with regard to stimulus specificity in avoidance learning.  相似文献   

Divergence of conditioned eyeblink and conditioned fear in backward Pavlovian training     

Kenneth A. McNish  Stephanie L. Betts  Susan E. Brandon  Allan R. Wagner 《Learning & behavior》1997,25(1):43-52

Two experiments of Pavlovian conditioning with rabbits evaluated the effects of initiating or continuing a conditioned stimulus (CS) after a paraorbital unconditioned stimulus (US). In Experiment 1, backward pairings, in which a CS came on after the US, produced a CS that appeared inhibitory on a measure of eyeblink conditioning but excitatory on a potentiated-startle measure of conditioned fear. In Experiment 2, extending the duration of a CS that came on prior to the US, so that it continued after the US, decreased eyeblink conditioned responses, whereas it increased conditioned fear. The data from the two experiments confirm and extend those of Tait and Saladin (1986), supporting the suppositions of AESOP (Wagner & Brandon, 1989) that conditioned eyeblink and conditioned fear can be dissociated under various temporal relationships between the CS and US.  相似文献   

Benzodiazepine administration prevents the use of error-correction mechanisms during fear extinction     

Genevra Hart  Nathan M. Holmes  Justin A. Harris  R. Frederick Westbrook 《Learning & behavior》2014,42(4):383-397

Three experiments examined the effect of systemic administration of the benzodiazepine midazolam on extinction and re-extinction of conditioned fear. Experiment 1 demonstrated that midazolam administration prior to extinction of a conditioned stimulus (CS) impaired that extinction when rats were subsequently tested drug free; however, extinction was spared if rats were extinguished, reconditioned, and re-extinguished under midazolam. Experiment 2 provided a replication of this effect within-subjects; rats were conditioned to two CSs (A and B), extinguished to one (A-), reconditioned to both, and then extinguished/re-extinguished to both stimuli in compound (AB-), under either vehicle or midazolam. On the drug-free test, rats given midazolam froze more to the CS that had been extinguished (B) than the one that been re-extinguished (A). The final experiment examined whether extinction under midazolam was regulated by prediction error. Rats were trained with three CSs (A, B, C) and extinguished to two (A-, C-). These stimuli then underwent additional extinction under midazolam or vehicle, with one CS now presented in compound with the non-extinguished CS (AB-, C-). Rats were then tested for fear of A relative to C. Rats given vehicle showed a deepening of extinction to A relative to C, as is predicted from error-correction models; however, rats given midazolam failed to show any such discrepancy in responding. The results are interpreted to indicate that the drug reduced prediction error during extinction by reducing fear, and rats were able to re-extinguish fear via a retrieval mechanism that is independent of prediction error.  相似文献   

Bidirectional heart rate responses in rats associated with excitatory and inhibitory stimuli     

John W. Hoffman  Robert D. Fitzgerald 《Learning & behavior》1982,10(1):77-82

Following classical conditioning to a shock-reinforced tone CS (T₁+), heart rate (HR) of three groups of rats was examined in response to a new reinforced tone (T₂+) and a nonreinforced light (L?) CS given during conditioned inhibition (T₂+ vs. T₁L?), discrimination conditioning (T₂+ vs. L?), or explicitly unpaired (T₂/L? vs. US alone) procedures. Decelerative HR reactions occurred to the reinforced T₂+ and T₂+ CSs. To the respective nonreinforced CSs, the conditioned inhibition group displayed diminished but sizable HR deceleration, the discrimination group showed near-zero responding, and the explicitly upaired group showed HR acceleration. Subsequent reversal conditioning to L was retarded in the conditioned inhibition and explicitly unpaired groups relative to the discrimination group. Group differences on combined-cue [T₂/L?) trials were not found. Both the HR responses during inhibitory training and the reversal-conditioning impairments suggest that inhibition may have been established to L? in the conditioned inhibition and explicitly unpaired groups.  相似文献   

One-trial excitatory backward conditioning as assessed by conditioned suppression of licking in rats: Concurrent observations of lick suppression and defensive behaviors     

John J. B. Ayres  Christopher Haddad  Melody Albert 《Learning & behavior》1987,15(2):212-217

Twenty-eight male albino rats were given a single 4-sec 1-mA electric-grid-shock unconditioned stimulus (US). In the same session they received two 12-sec conditioned stimuli (CSs). One CS (explicitly unpaired) terminated 180 sec before the US began; the other (backward paired) began immediately after the US terminated. The CSs used were a 1000-Hz 85-dB tone and an 84-dB click; their roles were counterbalanced. Over the next 2 days, each CS was presented for 2 min while the rats drank from a water bottle. The backward-paired CS was found to suppress licking more than the explicitly unpaired CS. This suppression was accompanied by an increase in defensive behavior (freezing and freeze/nod) and by a decrease in other activity. The suppression did not seem to be due to a maintained or enhanced CS-orienting response reflex, nor could it be attributed to an adventitiously reinforced interfering operant. The results support the presumption made in previous reports that the lick suppression evoked by a backward CS reflected one-trial backward excitatory fear conditioning.  相似文献   

Conditioned inhibition and the UCS-CS interval     

Steven F. Maier  Peter Rapaport  Kimbal L. Wheatley 《Learning & behavior》1976,4(2):217-220

The role of temporal factors in the development of conditioned inhibition was investigated in a backward conditioning design. Separate groups of rats received tone CSs either 3 or 30 sec following shock presentations. The CSs predicted the same shock-free interval for both groups. A third group was presented with a random relationship between CS and shock. The CSs were tested by super-imposition on a Sidman avoidance baseline and only the group with a 3-sec UCS-CS interval revealed an inhibitory effect of the CS. These results are in accord with predictions made by the Solomon-Corbit model of acquired motivation and by Denny’s “relaxation” theory of escape and avoidance.  相似文献   

Recovery from the overexpectation effect: Contrasting performance-focused and acquisition-focused models of retrospective revaluation     

Aaron P. Blaisdell  James C. Denniston  Ralph R. Miller 《Learning & behavior》2001,29(4):367-380

In four Pavlovian conditioned lick-suppression experiments, rats had two conditioned stimuli (CSs X and A) independently paired with footshock, followed by pairings of a compound of A and X with the footshock. On subsequent tests with CS X, less conditioned suppression was observed than in control subjects that lacked the compound AX→footshock trials. Thisoverexpectation effect was reversed through posttraining extinction of CS A, a result consistent with both performance- and acquisition-focused models of retrospective revaluation. However, only performance-focused models could account for how posttraining increases or decreases in the A-footshock temporal interval attenuate the overexpectation effect.  相似文献   

Pavlovian appetitive discriminative conditioning inAplysia californica     

Ruth M. Colwill  Kevin Goodrum  Andre Martin 《Learning & behavior》1997,25(3):268-276

Three experiments demonstrated Pavlovian appetitive discrimination learning in the marine mollusc,Aplysia californica. In each experiment, subjects were exposed to two conditioned stimuli; one stimulus (CS+) was paired with food presentations and the other stimulus (CS?) was never followed by food. In Experiments 1 and 3 different chemosensory stimuli were used, and in Experiment 2 different tactile stimuli were used. For both types of conditioned stimuli, bite responses occurred significantly more often to the CS+ than to the CS?. Experiment 2 also showed thatAplysia could learn a reversal of this discrimination. Experiment 3 showed that nonreinforced presentations of CS+ resulted in a decline in the frequency of conditioned biting. The implications of these results for neurobiological analyses of learning are discussed.  相似文献