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1.
Three experiments assessed the conditions that potentiate effects of an electroconvulsive shock (ECS) administered 24 h after avoidance training. Stimuli present immediately prior to the ECS were systematically varied. In Experiment 1, which employed a passive avoidance task, the primary determinant of whether the ECS disrupted retention was whether the situational cues present at the time of ECS delivery were those associated with the initial training experience: ECS disrupted performance only when it was administered in the original training apparatus, regardless of whether or not a footshock was presented immediately prior to ECS. In Experiment 2, which employed an active, shuttlebox avoidance task, both the situational cues from the training apparatus and a footshock were necessary to potentiate the disruptive effects of the ECS. Experiment 3 revealed that ECS effects on performance of the active avoidance task can also be potentiated by a combination of apparatus cues and the warning signal used in initial training. These results are interpreted as indicating that informational functions of stimuli present when an ECS is administered are important determinants of the effects of the ECS. 相似文献
2.
After one-way avoidance training, rats were exposed, during avoidance response prevention, to light (CS-only) presentations or to light-shock (CS-US) pairings. Subgroups were then given 1, 5, or 10 trials during which they could escape immediately (unrestricted) or after 5 sec (restricted) by means of the previously conditioned avoidance response from a simultaneous light-shock compound. All animals were then exposed to avoidance extinction. The number of unrestricted escapes increased responding for CS-only animals, but had no significant effect on the performance of CS-US animals. Nevertheless, resistance to extinction was considerably less for CS-only animals given 10 unrestricted escapes than for CS-US animals given one unrestricted escape. One restricted escape had no more effect than one unrestricted escape for either response-prevention group. However, 5 restricted escapes elevated responding for CS-only animals to the level of CS-US animals. Extinction responding for CS-US animals increased significantly only after 10 restricted escapes. Since CS-only animals showed no further increase, resistance to extinction once more was greater for CS-US animals. These results, together with the very brief unrestricted escape latencies of CS-only animals, support a greater role for Pavlovian extinction than for response competition in the facilitation of avoidance extinction by CS-only response prevention. The fact that 10 restricted escapes were required to elevate resistance to extinction for CS-US animals over that obtained with one unrestricted escape attests to the effectiveness of Pavlovian conditioning during avoidance response prevention in elevating CS aversiveness to a near ceiling level. 相似文献
3.
Masato Ishida 《Learning & behavior》1986,14(3):293-300
When extinction is delayed very long, the superior resistance to extinction of the random schedule group relative to the alternating schedule group disappears (partial reinforcement delayed extinction effect, PRDE). Two experiments assessed the effects of reinforcement/nonreinforcement on Trial 1 on the PRDE. Following extended partial reinforcement acquisition training in a runway, rats received extinction training after a short (1-day) or long (23-day) retention interval. The schedules used in Experiment 1 were: a single-alternation (SA) schedule beginning each day with a rewarded (r) trial, for Group r-SA; an SA schedule beginning with a nonrewarded (n) trial, for Group n-SA; and a random (Rd) schedule, for Group Rd. The schedules and group names used in Experiment 2 were r-SA, Rd, and r-Rd. The results were that (1) rats given r-SA schedules yielded considerable resistance under delayed extinction, (2) those given Rd and r-Rd schedules showed a decline in resistance to extinction over a long retention interval, (3) those given the n-SA schedule showed relatively low resistance at both retention intervals, although retention deficit was not greater than in the case of the Rd schedule, and thus, (4) the PRDE was found in both experiments, although only weakly in Experiment 1. The results indicated that a regularly alternating reward pattern was a more important determinant than was type of reward on Trial 1 for the PRDE. The PRDE due to differential retention deficits among schedules is discussed on the basis of dual-process associative sequential mechanisms and cognitive rule-encoding mechanisms. 相似文献
4.
Extinction of a conditioned palatability shift preceded extinction of conditioned taste avoidance whether rats were tested
using a within-subjects design or a between-subjects design. In each of two experiments, consumption of 0.1% saccharin was
paired with either 20 ml/kg of 0.15 M LiCl or equivolume physiological saline on a single trial. In Experiment 1, on each
of 10 extinction trials, rats were given a taste reactivity test immediately prior to a consumption test. In Experiment 2,
half of the rats were extinguished by taste reactivity testing and half of the rats were extinguished by a consumption test
on each of 10 extinction trials. In both experiments, the aversive reactions of gaping and passive dripping were extinguished
in a single trial and the suppression of ingestive reactions was extinguished in 2 trials; however, extinction of taste avoidance
required 4–5 trials. These results suggest that rats continue to avoid a lithium-paired flavor even when they do not have
an aversion to the taste. 相似文献
5.
Two experiments were carried out to study vertical jumping avoidance learning in rats. In particular, we examined the effects of the duration of a feedback stimulus and of the interval between the end of the feedback stimulus and the start of the next trial on acquisition and extinction of avoidance. In Experiment 1, the duration of feedback was manipulated while intertriai interval (feedback plus no-feedback) was held constant. Animals with feedback lasting more than 1 sec needed fewer trials to reach the acquisition criteria than did animals with no feedback or with 1-sec feedback. No differences were observed in extinction. In Experiment 2, the durations of both feedback and no-feedback were manipulated. Animals without feedback needed more trials to reach the acquisition criterion than did animals with feedback, but the performance of the feedback animals did not differ as a function of feedback duration, no-feedback duration, or total intertrial interval. Again, no differences were observed in extinction. These results indicate that the presentation of feedback improves the acquisition of vertical jumping avoidance, but that this effect is independent of the temporal characteristics of feedback. 相似文献
6.
Recent investigations have found a multiphasic retention function associated with avoidance training (e.g., Holloway & Wansley, 1973a, b). The present experiment was done to determine if a similar retention function also describes appetitively motivated behavior. Rats were allowed access to preferred solution in the shock compartment of a passive avoidance apparatus. Then either .25 h after the appetitive preexposure or at successive 3-h intervals up to 24 h, the rats were administered one-trial passive avoidance training consisting of a strong shock presented in the shock compartment. The retention of the appetitive preexposure was determined by its effect on performance of the passive avoidance task as measured 24 h after the shock trial. The results demonstrated that the retention function associated with the appetitive preexposure was phasic with an alternation between high and low retention every 12 h. Specifically, retention was higher after the .25-, 9-, 12-, and 24-h intervals than after 3-, 6-, 15-, and 18-h intervals. These results are consistent with prior research on the retention of avoidance training. 相似文献
7.
The “drug novelty hypothesis” was tested directly by giving rats experience with intraperitoneal injections of ethanol on days prior to avoidance training. This preavoidance experience with ethanol was found to eliminate the prolonged extinction of avoidance responding observed after a single exposure to ethanol. It is suggested that these findings confirm the novelty hypothesis in an active avoidance situation. Possible mechanisms of the drug novelty effect were discussed. 相似文献
8.
R. G. M. Morris 《Learning & behavior》1974,2(3):189-192
Variation in the intertrial interval (ITI) preceding a given trial is shown to have an independent and opposite effect upon leverpress avoidance performance to that caused by variation in ITI after a trial. This finding accounts for the opposite effect of overall ITI upon leverpress avoidance to its effect upon one-way avoidance without recourse to an associative explanation. The implications of this finding for recent discussions of response constraints upon avoidance learning is discussed. 相似文献
9.
The acquisition and extinction of locomotor responses of rats in a straight alley were examined for groups trained under escape, partial-avoidance, and avoidance procedures. During acquisition, one group (escape) received a 0-sec delay between being dropped into the alley and the onset of shock; two groups (partial avoidance) had 0.5- and 1-sec delays; and two groups (avoidance) had delays of 2 and 4 sec. On the final day of acquisition, the partial-avoidance rats displayed higher running speeds than either the escape- or avoidance-trained animals. The 4-sec avoidance group was consistently slower than all other groups. Speeds for all groups decreased during extinction, with rate of decline showing some relation to terminal acquisition level. Relative group performance levels proved to be consistent with a simple arithmetic model based on the assumption that changes in running speeds affect the aversiveness of the situation by altering US duration, CS duration, and effective US length. 相似文献
10.
Mice were trained to avoid shock by leaving a startbox and traversing a straight alley. During the first extinction phase (Phase I), two groups were given 30 regular extinction (RE) trials, while another two received punished extinction (PE) trials in the center of the alley. During the last 50 extinction trials (Phase II), conditions were reversed for one of the two groups receiving the same treatment in Phase I. This resulted in two nonshifted groups (RE-RE and PE-PE) and two shifted groups (RE-PE and PE-RE). PE treatment led to higher running speed in both phases and reversed an extinction trend. Furthermore, punishment-induced facilitation was greater for the group receiving PE following RE than for the group receiving PE immediately after avoidance training.
相似文献11.
The performance of four groups of mice of two genotypes (DBA/2J and C57BL/6J) was observed in two avoidance situations. Two groups, one of each strain, were given a maximum of 30 conditioning trials in an active avoidance situation followed by a maximum of 30 trials in a passive avoidance situation. The other two groups, one of each strain, were given passive avoidance conditioning first, followed by active avoidance conditioning. Positive transfer of training was observed in both genotypes for mice that received active avoidance conditioning prior to passive avoidance conditioning. Little or no transfer was observed from passive to active avoidance in either strain. 相似文献
12.
M. J. Homzie 《Learning & behavior》1974,2(1):77-79
Following a 47-day extinction procedure, the reinstatement of the cue previously associated with reward produced an immediate improvement in performance. The cue was the opportunity to traverse the alley following an “anticipated” nonrewarded runway trial. Moreover, the animals trained in this matter exhibited daily increments in performance during the initial phase of extinction testing. The results were interpreted as consistent with the notion that the difference in extinction performance of one group as compared to another does not necessarily reflect the relative “strengths” of the instrumentally acquired habits. Instead, it probably indicates the degree of similarity of the extinction testing procedure to the acquisition training condition previously associated with reinforcement for the two individual groups. 相似文献
13.
Food as a contextual cue in counterconditioning experiments: Is there a counterconditioning process?
In three experiments, counterconditioning was found to reduce fear less effectively than extinction. In Experiments 1 and 2, the resistance to extinction of avoidance was greater if food was given during extinction of fear to the CS than if no food was given, even when exposure to the CS and numbers of food and no food confinement trials were equated. It is suggested that these results could be attributed to contextual control of fear extinction by the food cue and/or to frustration produced by removing food for the counterconditioning group. Experiment 3 also found counterconditioning to be less effective than extinction and provided evidence that this difference occurs because of contextual control of fear extinction by the food cue. Measuring conditioned suppression of licking, in a test with no food present, less fear was shown if no food had been present during fear extinction, and greater fear was shown if no food had been present during fear conditioning. These results indicate that food is an important part of the context controlling fear and fear extinction. It is suggested that there may be no unique counterconditioning process. Rather, when counterconditioning procedures are employed, rules governing interference paradigms in general may apply. Thus, in a test for fear following counterconditioning, fear will be shown to the extent the test situation is similar to that in which fear conditioning occurred rather than that in which fear reduction occurred. 相似文献
14.
Mice were trained in a one-trial passive avoidance task and retested 2 min, 5 min, 10 min, 30 min, or 24 h later. A biphasic time-response curve was obtained with art initial increase to 5 min, a subsequent decrease, and another increase to 24 h. Other groups of Ss were administered electroconvulsive shock (ECS) 2, 5, 10, or 30 min after training and retested 24 h later. The response curve shape of the ECS-treated groups was found to correspond to that concerning the different retest times, suggesting a negative correlation between ECS amnesic effect and the strength of the conditioned response at the time of ECS administration. The inadequacy of the hypotheses, according to which ECS interferes with a gradual monotonic process, to explain ECS amnesic effect is discussed. 相似文献
15.
With a relatively complex maze, reliable forgetting is seen clearly when the training-to-test interval is 25 days. This forgetting is demonstrated by longer time to run the maze and by an increase in the number of errors and retracings from the last training trials to the first test trial. In this case, forgetting is a lapse, not a loss, since performance attains the last training trial level at a subsequent test. Furthermore, a reminder—a 90-sec exposure to background stimuli in the experimental room just prior to the test trial—that does not in itself contain sufficient information to facilitate performance in naive animals, significantly improves maze performance in rats that have “forgotten,” even on the first test trial. Two additional experiments were aimed at assessing the role of time and duration of pretest cuing. In the first experiment, the animals were presented the reminder (90 sec in duration) at different times before the test trial. The results show that this reminder significantly alleviates forgetting only when presented just prior to the test, and is less effective when given 1 or 24 h before the test. In the second experiment, contextual cues, which were presented just prior to testing in all experimental groups, varied in duration. The results showed that (1) animals given the reminder treatment for only 10 sec perform at the same level as controls; (2) cuing for 30 sec and especially for 90 sec alleviates forgetting; and (3) a longer exposure to background stimuli (300 sec) leads to intermediate levels of performance, probably due to a partial extinction of the cue value of these stimuli. 相似文献
16.
Normally, retention of an avoidance response by a rat is impaired when the test context is novel or does not correspond to the training context. Experiment 1 demonstrates that such an impairment of test performance can be alleviated if a rat receives a cuing treatment or reminder of training in the novel test context prior to testing. Experiment 2 indicates that when rats receive avoidance training in one context and then receive a reminder of training in a novel context, they perform more poorly when tested in the training context than do animals that receive no reminder. This finding is discussed in relation to current theories of contextual influence over retention performance. 相似文献
17.
Three experiments evaluated the effects of a single electroconvulsive shock in alleviating the learned helplessness effect in rats. The experiments differed primarily in terms of the location of the ECS treatment in the experimental sequence of events. In Experiment 1, ECS was given following helplessness training and testing and was evaluated during a retesting phase; in Experiment 2, ECS was given either immediately after helplessness training or immediately before helplessness testing; and, in Experiment 3, ECS was given prior to helplessness training. In all three experiments, significant helplessness effects occurred for subjects not receiving ECS but were absent in subjects receiving ECS. The data were compared with expectations arising from both amnesia-inducing and biochemical-change interpretations of the effects of ECS. 相似文献
18.
A task was designed to teach individual flies to avoid a lighted area after they had displayed an initial preference for it. The flies walked in a T-maze and chose between a lighted and a darkened alley leading, respectively, to a lighted and a darkened vial. Flies that were photopositive on a first trial were subjected to an aversive stimulus (a filter paper inserted into the lighted vial and wetted with a quinine solution), and they performed 16 training trials; they learned to avoid the lighted vial. The flies trained with water instead of quinine in the lighted vial still displayed avoidance of the lighted vial, but to a lesser extent. The flies trained with a dry filter paper in the lighted vial did not show any increase in avoidance during training. Like the flies trained with no quinine at all, those trained to avoid the lighted vial under a partial reinforcement condition (one half of the trials with quinine, the other half with a dry vial) did not master the task. Finally, removal of the quinine after an avoidance acquisition criterion was reached resulted in an extinction process. 相似文献
19.
Signaled avoidance was studied in individual honeybees that visited the laboratory regularly to take sucrose solution from a target set on the sill of an open window. During feeding, substrate vibration or airstream was used to signal a brief shock that could be avoided by breaking off contact with the food for a few seconds. Aversive conditioning of the context was measured in terms of return time (the time between successive visits). In Experiment 1, experience with unsignaled shock was found to lengthen return time—which experience with signaled shock did not—and to impair performance in subsequent avoidance training with signaled shock (the US-preexposure effect). In Experiment 2, experience with unsignaled shock given after signaled avoidance training lengthened return time but had no effect on response to the signal in a subsequent extinction test. These results closely resemble the results obtained in analogous experiments with vertebrates. 相似文献
20.
In three experiments in which rats were used as subjects, we developed an extinction procedure using a Morris pool. The animals were trained to find a hidden platform located at a fixed position and were then given extinction trials in which the platform was removed from the pool. When training and extinction were carried out in the same context and time was allowed to elapse between extinction and test, spontaneous recovery of learning was observed. On the other hand, those rats that received extinction in a context different from the one used for training failed to show spontaneous recovery of learning when tested in the extinction context after an interval of 96 h. However, they did show renewal of spatial learning when tested in the training context. These results show that extinction in the spatial domain behaves like extinction in standard conditioning preparations. 相似文献