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1.
Water-deprived adult rats were used in a conditioned-suppression-of-licking procedure to determine the effect of inhibitory training with a novel stimulus trained in simultaneous compound with a previously established conditioned inhibitor. This procedure constitutes an inhibitory analogue to the excitatory blocking procedure in classical conditioning. The conditioned-inhibition training consisted of either explicitly unpaired CS and US presentations or negative contingency training, in which the likelihood of the US was greater in the absence than in the presence of the CS, but the CS and the US were occasionally paired. To assess conditioned inhibition, a retardation test was used, and comparable retardation was obtained for subjects that were administered the blocking treatment and control subjects given similar conditioned-inhibition training with a compound stimulus in which the nontarget element was not previously established as a conditioned inhibitor. 相似文献
2.
Most associative theories have assumed that stimulus competition occurs only between conditioned stimuli (CSs) that are trained in compound. The present research investigated the possibility of competition between two CSs that were individually paired to the same unconditioned stimulus (US). We used human subjects in an anticipatory suppression analogue to Pavlovian conditioning. Experiment 1 showed that X+ training followed by A+ training resulted in impaired responding to X. This did not occur when A+ training preceded X+ training. Experiment 2 replicated the basic effect and showed that it did not occur when the Phase 2 training consisted of A? instead of A+ nor when the A+ pairings occurred in a second context. Experiment 3 showed that A+ pairings occurring in a second context could still produce the effect when X was tested in the context in which the A+ pairings had occurred, but not when X was tested in a context different from that used for A+ training. Collectively, these results suggest that individually trained CSs may compete with each other when one of those CSs is more strongly activated by the test context than the other one. 相似文献
3.
Conditioned cardiac and behavioral responses to an olfactory stimulus (CS) paired with electric shock (US) were studied in 16-, 23-, and 75-day-old rats. Heart rate and behavior were recorded during a single 15-trial training session in which a 10-sec olfactory stimulus (amyl acetate) was either paired or explicitly unpaired with the US. In the preweanling rats, the conditioned cardiac response consisted of anincrease in heart rate (tachycardia) and a slight increase in investigatory behaviors. In contrast, the conditioned cardiac response in the adult rats consisted of adecrease in heart rate (bradycardia) and a striking increase in behavioral immobility (freezing). The 23-day-old rats showed a dichotomous pattern of responding; some showed preweanling-like conditioned responses and some showed adultlike responses. Developmental changes in neural organization and degree of learning are discussed as possible determinants of the transition from infant to adult modes of responding. 相似文献
4.
We used an appetitive sensory preconditioning procedure to investigate temporal integration in rats in two experiments. In
Phase 1, rats were presented with simultaneous compound trials on which a 10-sec conditioned stimulus (CS) X was embedded
within a 60-sec CS A. In Group Early, CS X occurred during the early portion of CS A, whereas in Group Late, CS X occurred
during the latter portion of CS A. In Phase 2, CS X was paired simultaneously with sucrose. On a subsequent test with CS A,
the rate of magazine entries peaked during the early portions of the stimulus in Group Early and during the latter portions
of the stimulus in Group Late (Experiments 1 and 2). Similar response peaks were not observed on tests with a control stimulus
that had been presented in compound with a stimulus that did not signal reward (Experiment 2). 相似文献
5.
Peter C. Holland 《Learning & behavior》2018,46(2):134-156
Prior exposure to a conditioned stimulus (CS) typically results in latent inhibition—slower acquisition of associative learning about that stimulus in subsequent training. Here, we found that CS preexposure had different effects on the appetitive conditioning of rats with a sucrose unconditioned stimulus (US) depending on training test procedures, the similarity of preexposure and training procedures, and the choice of response measure. Preexposure to a visual or an auditory stimulus produced facilitation of acquisition of food-cup-directed responding when both of those cues were (separately) paired with sucrose delivery in the training test (Experiments 1 and 3). By contrast, the same preexposure procedure resulted in latent inhibition of food-cup learning if the second stimulus in the test phase was of the same modality as the preexposed stimulus (Experiment 2). In Experiment 3, latent inhibition was enhanced if both phases included a single CS or both phases included both auditory and visual CSs, compared to treatments in which only one CS was presented in one phase but two CSs were presented in the other phase. In Experiment 4, preexposure of an auditory cue slowed subsequent learning about it if the context was salient but enhanced learning if the context was of weaker salience. Finally, a measure of general activity revealed latent inhibition after preexposure in all conditions in all 4 experiments. We discuss the results within several classes of latent inhibition theories, none of which provides a comprehensive account. 相似文献
6.
Anthony S. Rauhut Janice E. Mcphee Norma T. Dipietro John J. B. Ayres 《Learning & behavior》2000,28(1):92-108
In each of two experiments, we studied Pavlovian fear conditioning (as assessed by barpress conditioned suppression) in 32 albino rats. Following a two-stage cue-competition procedure (A+ then AX+), we subjected the competing cue (A) to conditioned inhibition training (B+, BA?) before testing the target cue (X). Conditioned inhibition training was designed to weaken the putative A-unconditioned stimulus (US) association, perhaps changing it to an A-no-US association. Performance-deficit theories of cue competition, such as comparator theory and retrieval-interference theory, predict that such procedures should weaken cue competition, causing Conditioned Stimulus X (CS X) to evoke strong responding. The same prediction can be deduced from recent acquisition-focused models (Dickinson &; Burke, 1996; Van Hamme &; Wasserman, 1994). In opposition to this prediction, however, we found in both experiments that conditioned inhibition training had no detectable effect on cue competition even though it successfully abolished conditioned responding to CS A. In Experiment 2, moreover, we found evidence against the hypothesis that the weak response to CS X was due to generalization decrement rather than to cue competition. Results favor early learning-deficit theories of cue competition over performance-deficit theories and over the recent acquisition-focused models. 相似文献
7.
Pamela S. Hunt 《Learning & behavior》1997,25(3):301-311
Preweanling rats, 16 days of age, responded to an olfactory conditioned stimulus (CS) paired with a shock unconditioned stimulus (US) with increases in heart rate and behavioral activation. In two experiments this finding was replicated and, in addition, it was found that the form of these conditioned responses (CRs) changed after a retention interval. When tested 24 h after CS-US pairings, the subjects displayed a decrease in heart rate accompanied by CS-elicited freezing. Giving two unsignaled shocks prior to the delayed test effectively reinstated the tachycardia and behavioral arousal CRs. The results are discussed in terms of contextual influences on the form of the CR and how changes in the magnitude of context fear may alter responding to an olfactory CS. 相似文献
8.
Prior research has demonstrated renewal, which is the ability of contextual cues to modulate excitatory responding to a Pavlovian conditioned stimulus (CS). In the present research, conditioned lick suppression in rats was used to examine similar contextual modulation of Pavlovian conditioned inhibition. After Pavlovian conditioned inhibition training with a CS in one context, subjects were exposed to pairings of the CS with an unconditioned stimulus (US) either in the same or in a second context. Results indicated that, when the CS was paired with the US in the second context, the CS retained its inhibitory control over behavior, provided that testing occurred in the context used for inhibition training. However, when the CS-US pairings occurred in the inhibition training context, the CS subsequently proved to be excitatory regardless of where testing occurred. These observations indicate that conditioned inhibition is subject to renewal. 相似文献
9.
Two lick suppression experiments with rats were conducted in order to determine the nature of the temporal information that is encoded as a result of Pavlovian conditioned inhibition training (conditioned stimulus {CS} A→unconditioned stimulus {US}/AX→noUS). After inhibition training, the conditioned inhibitor (X) was paired with the US in order to measure inhibition, as assessed through retarded behavioral control by CS X. Three temporal relationships were manipulated: the A-US interval, the X-A interval of inhibition training, and the X-US interval of the retardation test pairings. Retardation was greatest when the X-US temporal relationship matched the time at which the US was expected (but not delivered) on the X-A inhibition training trials. Thus, the present experiments provide evidence with retardation tests that, during conditioned inhibition training, subjects encode the temporal location of the omitted US relative to the inhibitory CS. These findings complement those of previous studies using summation tests of conditioned inhibition (Barnet & Miller, 1996; Denniston, Blaisdell, á Miller, 1998; Denniston, Cole, & Miller, 1998). 相似文献
10.
Little responding develops to a conditioned stimulus (CS) that is placed in a random relation to an unconditioned stimulus (US). However, if the USs not preceded by that CS are themselves signaled by another stimulus, then the CS does come to elicit responding. This result has been attributed (e.g., by Durlach, 1983) to the signal’s blocking of conditioning to background cues that otherwise would prevent conditioning of the CS. However, Goddard and Jenkins (1987) have suggested the alternative that signaling the USs promotes responding due to the adventitious creation of periods of signaled nonreinforcement. Two experiments were conducted to assess this alternative, involving an autoshaping preparation in pigeons. In Experiment 1, little responding to a keylight CS presented in a random relation to a food US occurred, despite the explicit presentation of a discrete noise signaling periods of no food in the intertrial interval (ITI). Experiment 2 was designed to replicate the procedure of Goddard and Jenkins, in which an auditory stimulus extended throughout the ITI of a random schedule, terminating only prior to extra USs and during the CS. Contrary to their findings, little responding developed to the target CS. However, responding did develop when the sound-free period occurred only prior to the extra USs. These results offer little support for the hypothesis that signaled periods of nonreinforcement promote responding on random schedules. However, they are consistent with the view that signaling of ITI USs acts by preventing conditioning of potentially competitive background cues. 相似文献
11.
The present research examined the temporal distribution of responding in a lick suppression paradigm. In Experiment 1, rats were trained with either a 30- or a 120-s conditioned stimulus (CS), which was followed either by a footshock (unconditioned
stimulus [US]) or nothing. Licking during the CS was suppressed only in the former condition. Suppression was more pronounced
early in the CS. In Experiment 2, rats were exposed to two 30-s or two 120-s CSs, with delivery of the shock being contingent on CS1 for half of the animals
and on CS2 for the other half. For both the paired and the unpaired conditions, suppression at the beginning of CS1 was observed
for all the groups. By discounting the possibility of generalization between CS1 and CS2, it appears that this initial suppression
was not a conditioned response to the CS, but an unconditioned one due to mere exposure to the shock US. 相似文献
12.
When the conditioned stimulus (CS) is located some distance from the unconditioned stimulus (US), pairings of the CS and US can yield either conditioned approach to the CS (sign tracking) or conditioned approach to the US (goal tracking). However, goal tracking is the more common outcome, and, because of that, goal tracking has come to serve as a “standard” measure of associative learning in several laboratories. In contrast, in previous studies of sexual conditioning with domesticated quail, only sign tracking was observed. In the present study, quail continued to show sign tracking rather than goal tracking whether or not the US was highly localized (Experiment 1), whether food or a sexual US was used (Experiment 2), whether the CS was mobile or immobile (Experiment 3), and whether the CS was 91 or 233 cm from the US compartment (Experiment 4). The present findings encourage caution in the routine use of goal tracking as a measure of learning. The possible mechanisms of goal tracking are discussed in terms of occasion setting and behavior systems theory. 相似文献
13.
William Timberlake 《Learning & behavior》1986,14(3):276-286
The present experiments explored the relation between a mode of behavior produced by unpredicted presentations of an unconditioned stimulus (US) and subsequent interference with responding to a conditioned stimulus (CS) (the context-blocking effect). The US was food, the CS was a moving ball bearing, and the subjects were rats. The typical response to a moving bearing that predicts food is predatory interaction, and the behaviors that developed under unpredicted US presentations involved focused search and waiting oriented to the food tray. Experiment 1 manipulated the number of unpredicted food presentations and showed that the reduction in subsequent bearing contacts was more clearly related to the occurrence of initial food-tray behavior than to the number of prior food presentations. Experiments 2 and 3 manipulated the conditioning of food-tray behavior while holding constant the number of prior food presentations, and again showed a strong inverse relationship between initial food-tray behavior and ball-bearing contact. The latter experiments also indicated that the locus of interference with bearing-directed behavior was neither primarily central (associative or attentional) nor peripheral (motor interference), but resulted from the incompatibility of two modes of food-getting behavior, a more general predatory search mode versus a mode of focal search and waiting. A behavior-system account of these results does not preclude an associative basis for context-blocking effects, but it argues that such effects may occur at several levels and must function within appetitive structures underlying the animal’s food-getting behavior. 相似文献
14.
The blocking phenomenon was investigated in the sexual response system of male Japanese quail. Access to a live female quail served as the unconditioned stimulus (US). The same audiovisual cue served as the pretrained stimulus in all of the experiments. Following asymptotic conditioning of the audiovisual cue, a second conditioned stimulus (CS2) was added. In Experiment 1, CS2 was a rectangular wood block that had little or no resemblance to a female quail and could not support copulatory behavior. In Experiment 2, CS2 was a terrycloth object that had no quail parts but could support copulatory behavior, and, in Experiment 3, CS2 was a terrycloth object that had a taxidermically prepared head of a female quail added. The terrycloth-only object supported more rapid conditioning than did the wood block, but the blocking effect was obtained with both kinds of stimuli. Approach responding to the terrycloth + head object required pairing it with copulatory opportunity, and the terrycloth + head object supported at least as rapid conditioning as did the terrycloth-only object. However, responding to the terrycloth + head object was not blocked by the pretrained audiovisual cue. These results indicate that the blocking effect occurs in sexual conditioning even with stimulus objects that can support copulation. However, the addition of species-typical head cues to an object makes that object such a powerful stimulus that conditioned approach responding to it cannot be blocked by a previously conditioned arbitrary audiovisual cue. 相似文献
15.
Conditioned lick suppression in rats was used to explore the role of timing in trace conditioning. In Experiment 1, two groups of rats were exposed to pairings of a CS (CS1) with a US, under conditions in which the interstimulus interval (ISI) that separated CS1 offset and US onset was either 0 or 5 sec. Two additional groups were also exposed to the same CS1→US pairings with either a 0 or a 5-sec ISI, and then received “backward” second-order conditioning in which CS1 was immediately followed by a novel CS2 (i.e., CS1→CS2). A trace conditioning deficit was observed in that the CS1 conditioned with the 5-sec gap supported less excitatory responding than the CS1 conditioned with the 0-sec gap. However, CS2 elicited more conditioned responding in the group trained with the 5-sec CS1-US gap than in the group trained with the 0-sec CS1-US gap. Thus, the CS1-US interval had inverse effects on first- and second-order conditioned responding. Experiment 2 was conducted as a sensory preconditioning analogue to Experiment 1. In Experiment 2, rats received the CS1?CS2 pairings prior to the CS1→US pairings (in which CS1 was again conditioned with either a 0 or a 5-sec ISI). Experiment 2 showed a dissociation between first- and second-order conditioned responding similar to that observed in Experiment 1. These outcomes are not compatible with the view that differences in responding to CSs conditioned with different ISIs are mediated exclusively by differences in associative value. The results are discussed in the framework of the temporal coding hypothesis, according to which temporal relationships between events are encoded in elementary associations. 相似文献
16.
Three conditioned lick suppression experiments with rats were performed to assess the influence, following compound training
of two stimuli (A and X) with the same outcome (AX-O trials), of extending training of the blocking association (i.e., A-O)
on responding to the target stimulus (X) at test. In Experiment 1, backward blocking was attenuated when the blocking association
was extensively trained. Experiment 2 showed that forward blocking was also attenuated by extensive further training of the
blocking association following the AX-O trials. Experiment 3 contrasted candidate explanations of the results of Experiments
1 and 2 and demonstrated that these results are consistent with the framework of the extended comparator hypothesis (Denniston,
Savastano, & Miller, 2001). 相似文献
17.
Joint presentations of a conditioned stimulus (CS) and an unconditioned stimulus (US) strengthen the contingency between them, whereas presentations of one stimulus without the other degrade this contingency. For example, the CS can be presented without the US either before conditioning (CS–no US and then CS–US; latent inhibition) or after conditioning (CS–US and then CS–no US; extinction). In vertebrate subjects and several invertebrate species, a time lapse usually results in a return of the conditioned response, or spontaneous recovery. However, in land mollusks, spontaneous recovery from extinction has only recently been reported, and response recovery after latent inhibition has not been reported. In two experiments, using conditioned aversion to a food odor as a measure of learning and memory retention, we observed contingency degradation via latent inhibition (Experiment 1) and extinction (Experiment 2) in the common garden slug, Lehmannia valentiana. In both situations, the contingency degradation procedure successfully attenuated conditioned responding, and delaying testing by several days resulted in recovery of the conditioned response. This suggests that the CS–US association survived the degradation manipulation and was retained over an interval of several days. 相似文献
18.
Two experiments investigated extinction and blocking of a conditioned inhibitor in a human contingency learning task. Lotz
and Lachnit (2009) and Melchers, Wolff, and Lachnit (2006) reported extinction of inhibition only when participants experienced
outcome levels lower than those used in training. In Experiment 1, which used more neutral instructions than the previously
mentioned studies, we found that extinction of inhibition occurred, whether or not participants experienced lower outcome
levels. In Experiment 2, we applied this outcome manipulation to blocking of a conditioned inhibitor. We found blocking of
inhibition both when participants had experience with lower outcomes and when they did not. The results of our two experiments
are consistent with Rescorla and Wagner’s (1972) associative model, and inconsistent with an inferential account of causal
learning (De Houwer, Beckers, & Vandorpe, 2005). 相似文献
19.
In two experiments with rat subjects, we examined the effects of a retention interval on performance in two conditioning paradigms in which a conditioned stimulus (CS) was associated with different unconditioned stimuli (USs) in successive phases of the experiment- Experiment 1 was designed to examine aversive-appetitive transfer, in which the CS is associated with shock and then food; Experiment 2 was designed to examine appetitive-aversive transfer, in which the CS is associated with food and then shock. Aversive and appetitive conditioned responses (freezing and head-jerk responding, respectively) were scored from videotape. In both experiments, a 28-day retention interval following the end of Phase 2 caused a recovery of the Phase 1 response and a resuppression of the Phase 2 response. The results suggest that the original association is not destroyed when the CS is associated with a new US in Phase 2. They also suggest that both retroactive and proactive interference effects may result-from interference with performance output rather than a disruption or loss of what is learned during or stored from the target phase. 相似文献
20.
Sexual responses were conditioned in male Japanese quail using the opportunity to copulate with a female as the unconditioned stimulus (US). The conditioned stimulus (CS) was a 3-D object made of a taxidermically prepared female quail head mounted on a terry-cloth body. Both appetitive conditioned responses (approach and proximity to the CS) and consummatory conditioned responses (mount and cloacal contact directed toward the CS) developed when 2-min presentations of the CS were followed immediately by the US, but not when the CS and US were separated by trace intervals of 10 or 20 min (Experiment 1). Postconditioning sexual satiation suppressed conditioned cloacal contact responses more than conditioned approach to the CS (Experiment 2), and “acute” extinction suppressed both conditioned mounting and conditioned cloacal contact responses more than conditioned approach to the CS (Experiment 3). These results demonstrate a functional dissociation between conditioned appetitive and consummatory responses and imply that the motivational and/or associative mechanisms underlying the two types of behavior are distinct. 相似文献