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1.
Ontogenetic changes in the role of proactive interference in augmenting forgetting were tested with 444 rats as subjects. In Experiment 1, Phase 1 (the source of proactive interference) included events that were contingent or not contingent on responding in the context of either the Phase 2 training apparatus or a distinctly different apparatus. After learning a spatial discrimination for Phase 2, retention tests were given after intervals of 2 min, 1 day, 7 days, 30 days, or 65 days. The results indicated: (1) infantile amnesia, and (2) proactive interference for infant rats but not for adults, in spite of substantial simple forgetting among adults. Experiment 2 extended the test to a go/no-go avoidance task. The results of Experiment 2 gave some indication that infants were more susceptible than were adults to proactive interference over short intervals, but the generality of this relationship was sufficiently ambiguous as to suggest different mechanisms of interference for the discrimination and go/no-go tasks. These data indicate multiple mechanisms of infantile forgetting that may vary with certain characteristics of the task. 相似文献
2.
In Experiment 1, hungry rats received 30 rewarded runway trials and then either extinction trials followed by retention tests or just retention tests. Different groups were tested after retention intervals of 1 min, 1, 3, or 24 h, or 30 days. Retention of extinction training was a nonmonotonic, cubic function of time for the early portion of the response chain, with good retention at 1 min and 3 h and little retention at 1 h, 24 h, or 30 days. In the latter portions of the response chain, retention of extinction decreased monotonically with time. Retention following reward-only training varied little in time, though slight losses occurred after 30 days. Experiments 2–3 differed from Experiment 1 in imposing nonchoice discrimination training (reward vs. nonreward) instead of extinction following 30 rewarded trials. After different time intervals (.017, .75, 1.25, 3, and 24 h in Experiment 1; and .017, 1, and 3 h in Experiment 2), retention tests revealed poorest discrimination at intermediate intervals in the initial portion of the response chain, i.e., a Kamin effect appeared. The deficit seemed the result of a loss of response suppression to the cue that signaled nonreward. In latter segments of the response chain, a Kamin effect tended not to appear. Implications for a number of observations and theoretical views are noted. 相似文献
3.
The main aim of this series of experiments was to clearly establish the spontaneous development of retention performance following partial aversively motivated training. Experiment 1 indicated that following 15 training trials of a brightness discrimination in a Y-maze, performance spontaneously and transitorily deteriorated 1 h following inital training (Kamin effect) before it improved 8 to 14 days following training (long-term spontaneous improvement). Both of these fluctuations preceded the more durable deterioration that corresponds to long-term forgetting. Experiment 2 replicated the basic findings of the first experiment, always with a brightness discrimination, but using an avoidance paradigm. These results demonstrated the multiphasic nature of the retention curve and emphasized the reliability of retention performance fluctuations. 相似文献
4.
In six experiments, we examined taste and compound taste/taste aversions at different retention intervals. In Experiment 1, saccharin aversions were significantly weaker 1 day after conditioning than 21 days after conditioning. This effect was determined not to be caused by the aftereffects of illness or differential hydration. With the use of a saccharin/denatonium compound, Experiment 2 demonstrated overshadowing of a denatonium aversion at 21- and 1-day retention intervals, Experiment 4 showed a potentiated saccharin aversion only at the 21-day retention interval, and both Experiments 2 and 4 revealed that the aversion of the taste-only controls was stronger at the later retention interval. Experiments 3 and 5 demonstrated that the differences at the two retention intervals were not caused by unconditioned changes in taste preference. Finally, Experiment 6 showed that extinction of the conditioning environment prior to testing results in stronger saccharin aversions than occur in nonextinguished controls. Collectively, these experiments suggest that testing within a 24-h period after conditioning will result in significantly weaker taste aversions. Also, these results support a retrieval-competition explanation that may account for the weakened aversions at the 1-day testing interval of both groups conditioned to single elements and those conditioned to compounds. 相似文献
5.
Imposition of a retention interval between cue-outcome pairings and testing can alleviate the retardation of conditioned responding induced by pretraining exposure to the cue (i.e., the CS-preexposure effect). However, recent studies have reported an enhanced effect of CS-preexposure treatment with longer retention intervals (De la Casa & Lubow, 2000, 2002; Lubow & De la Casa, 2002). In a series of conditioned barpress suppression studies with rats, we examined the effects of imposing a retention interval just prior to testing following either CS-preexposure (cue alone before cue-outcome pairings) or extinction (cue alone after cue-outcome pairings) treatments. Experiment 1 replicated in a different preparation recent reports of CS-preexposure treatment effects increasing with longer retention intervals. Experiment 2 showed that spontaneous recovery of stimulus control of behavior after extinction can be obtained with the same parameters as those used to observe the augmented effect of CS-preexposure treatment. In Experiment 3, both the augmented effect of CS-preexposure treatment and spontaneous recovery from extinction were found when we used, in place of a retention interval, an associative priming manipulation. 相似文献
6.
Prior cuing treatments intended to alleviate the forgetting of a conditioned avexsion-to an odor were tested with 18-day-old rats. Previous experiments had shown that when such pups were conditioned with the use of a CS?/CS+ procedure, pretest presentation of the CS? or US, but not the CS+, alleviated the forgetting otherwise seen after a 3-h retention interval. In Experiment 1, it was determined that the forgetting was not alleviated if the GS? was either preceded or followed by presentation of the CS+, despite the fact that the CS?/CS+ ordering mimicked that of original conditioning. Experiment 2 was an examination of the balance of extinction and reactivation effects caused by presenting the CS+ for varying durations following the 3-h retention interval. The forgetting over this interval was alleviated if the CS+ was presented for 5 or 15 sec, but not 30 sec. With an increase in duration of exposure from 15 to 30 sec, the consequences of the CS+ as a prior cuing treatment apparently shifted from reactivation to extinction. Experiment 3 was a test of the interaction between the consequences of different lengths of CS+ exposure and the effectiveness of adding CS? to the CS+ as a reactivation treatment. The varied effectiveness of reactivation treatments is discussed interms of a change in stimulus conditions from training to reactivation. 相似文献
7.
Two experiments employed a delayed conditional discrimination procedure in which half the trials began with the presentation of food and half with no food; following a retention interval, subjects were presented with a choice between red and green keys, a response to one of which was reinforced according to whether the trial had started with food or no food. In Experiment 1, after 38 training sessions during which the retention interval was gradually increased, pigeons performed at a moderate level with intervals of 5 to 7.5 sec. A final test produced a steep forgetting function for food trials, but not for no-food trials; performance was unaffected by the duration of the intertriai interval (10 or 40 sec). Experiment 2 used the delayed conditional discrimination procedure to compare short-term memory in jackdaws (Corvus monedulus) with that in pigeons. Although the performance of the jackdaws was below that of the pigeons at the start of training, they showed more rapid learning over long delays, and, in the final test, a shallower forgetting function for food trials than that shown by pigeons. The results suggested superior short-term memory in jackdaws, which may help to explain the better performance of corvids in general when compared with that of pigeons in certain complex learning tasks. 相似文献
8.
Pigeons trained on a conditional event-duration discrimination typically “choose short” when retention intervals are inserted between samples and comparisons. In two experiments, we tested the hypothesis that this effect results from ambiguity produced by the similarity of the novel retention intervals and the familiar intertrial interval by training pigeons with retention intervals from the outset and, for one group, in addition, making retention intervals distinctive from the intertrial intervals. In Experiment 1, when the retention intervals (0–4 sec) were not distinctive from the intertrial intervals, the pigeons did not show a clear choose-short effect even when extended retention intervals (8 sec) were introduced. When the retention intervals were distinctive, the pigeons showed a choose-long effect (they appeared to time through the retention interval), but it was relatively weak until the retention intervals were extended to 8 sec. In Experiment 2, when pigeons were discouraged from timing through the retention intervals by making the intertrial intervals and retention intervals salient distinct events and using long (up to 16-sec) retention intervals in training, parallel retention functions were found. It appears that when ambiguity is removed, forgetting by pigeons does not occur by the process of subjective shortening. These experiments suggest that the accurate interpretation of results of animal memory research using differential-duration samples must consider the novelty of the retention intervals on test trials as well as their similarity to other trial events. 相似文献
9.
In two experiments, pigeons' responding on an extraneous task was explicitly reinforced during delayed matching-to-sample
trials. In Experiment 1, red or green sample stimuli were followed by retention intervals of 0.2, 1, 4, or 12 sec, during
which pecks to a white center key were reinforced with 2.5-sec access to wheat according to extinction, variable-interval
30-sec, and variable-interval 15-sec schedules in different conditions. A proportion of .2, .5, .7, or .9 of subsequent red
or green choice responses that matched the sample were reinforced with 3-sec access to wheat. The result was that increasing
center key reinforcement, or reducing reinforcer probability, lowered overall accuracy. Initial discriminability fell, but
with no change in the rate of forgetting. In Experiment 2, initial discriminability was affected by extraneous reinforcers
that were contingent on center key pecking, but not by noncontingent reinforcers. A plausible conclusion is that initial discriminability
decreases when reinforcers strengthen competing behaviors. 相似文献
10.
A series of experiments were run to test the hypothesis that “spontaneous forgetting” could result from subtle contextual changes. The first experiment demonstrated that when Sprague-Dawley male rats are trained in a runway alley with a food reinforcer, retention performance is dramatically affected by a change in the pattern of the walls of the training apparatus when testing takes place 1, 3, or 5 days following training and not after 1 week. Experiment 2 demonstrated that this performance deficit cannot be alleviated by any of the three selected cuing treatments, whereas “spontaneous forgetting” (resulting from a training-to-test interval of 14 days) can be. These data indicate that the detrimental effect of contextual change reduces over time, and that such an effect cannot be interpreted in terms of retrieval failure. These results lend strong support to the argument that the disruptive contextual change effect is basically different from the disruptive effect that results from an extended training-to-test interval. 相似文献
11.
Four experiments are reported in which pigeons first learned one wavelength discrimination (green S+, yellow S?) and then the reversal; finally, after various delays, they were tested for wavelength generalization in extinction. In Experiment 1, the two problems were learned in different contexts; testing in Context 1 produced maximal responding to green in only half of the subjects, even when testing was delayed 30 days. In Experiment 2, testing of the subjects repeatedly in both contexts showed good control by each context after a 30-day delay. In Experiment 3, both problems were learned in the same context, and all gradients showed recency, peaking at yellow, even after 30 days. In Experiment 4, the subjects learned a series of reversals in the same context, terminating in yellow, S+, green, S?, and their gradients peaked at yellow, even after a 30-day delay. In Experiments 3 and 4, the gradients became flatter with increasing delays, and they were flatter in Experiment 4 (after three reversals) than in Experiment 3 (after one reversal). The location of the peak was not affected by delay, but only by testing in a context that had been uniquely associated with Problem 1 (Experiments 1 and 2). It is proposed that the location of gradient peaks indicates what is being remembered, whereas the slope of the obtained gradients indicates how well the target memory has been retrieved. 相似文献
12.
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
13.
Auditory Context and Memory Retrieval in Young Infants 总被引：1，自引：0，他引：1
Jeffrey Fagen Joyce Prigot Marjorie Carroll Liane Pioli Adam Stein Adriana Franco 《Child development》1997,68(6):1057-1066
Three-month-old infants were trained to move an overhead crib mobile while 1 of 2 musical selections was played. Retention was assessed 1 or 7 days later in the presence of either the same music or a different musical selection. in Experiment 1, the musical selections were very different (classical versus jazz); in Experiment 2, they were much more similar (two classical pieces). Infants in both experiments displayed 1 day retention regardless of wich music was played during the retention test. At 7 days, retention was seen only when the music played during the retention test matched the training music. These data are consistent with similar findings showing that 3-month-old infants'memory is disrupted at long retention intervals when the context present during retention testing does not match the learning context. As the infant's memory wanes, context appears to function as a necessary cue for the retrieval of acquired expectancies. 相似文献
14.
Based on several recent demonstrations of a directed forgetting effect in pigeons, three experiments were carried out in an attempt to demonstrate directed forgetting in three squirrel monkeys. During initial training with a delayed matching-to-sample procedure, retention tests were always given for sample stimuli followed by remember cues (R-cues) and were always omitted for sample stimuli followed by forget cues (F-cues). Retention of F-cued items was tested on probe trials after initial training. The first two experiments examined the effects of R- and F-cues on memory for slide-projected pictures, with different pictures used on each trial of a session. In Experiment 1, a complex design was used in which one or two sample pictures were presented on each trial; when two pictures were presented, both could be R-cued or F-cued, or one could be R-cued and the other F-cued. A simpler design was used in Experiment 2, with only single pictures presented as sample stimuli and half the trials within a session R-cued and the other half F-cued. In both of these experiments, no differential retention of R- and F-cued stimuli was found, even at a retention interval as long as 16 sec. In Experiment 3, a series of studies was performed to test for directed forgetting when only two sample stimuli were used repeatedly throughout training and testing. With two pictures as sample stimuli, clear evidence of directed forgetting was found in Experiment 3b. It is suggested that the directed forgetting effect may arise only when a small set of sample stimuli is used. 相似文献
15.
The effects of age on the forgetting of stimulus attributes in a differential fear-conditioning paradigm were examined with
18- and 70-day-old rats tested in either the original conditions or shifted stimulating conditions at one of three retention
intervals (1, 48, and 120 h). Adults displayed significant shifts at each retention interval, with those tested in the original
context displaying greater fear than those tested in the shifted conditions. By contrast, by 48 h the 18-day-olds had forgotten
the specific attributes of the training situation and began treating the two stimulating conditions as functionally equivalent
(Experiment 1). In Experiment 2, we tracked the ontogenetic emergence of adult-like memory for stimulus attributes and found
a dramatic increase in memory capability by 25 days of age. Experiment 3 illustrated that the forgotten memory attributes
of infants may be retrieved by administering a 90-sec cuing treatment 10 min prior to the 48-h test. Implications for the
phenomenon of infantile amnesia are discussed. 相似文献
16.
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
17.
Four experiments examined whether or not spontaneous recovery could occur after extinction in the conditioned taste-aversion paradigm. After three extinction trials, spontaneous recovery was obtained over an 18-day retention interval (Experiments 1, 2, and 3). The effect was not due to changes in the unconditioned preference for saccharin over the retention interval (Experiment 2) or to an increase in a nonextinguished aversion over time, as indicated by tests with both the original, nonextinguished aversion (Experiment 1) and with a weaker one (Experiment 3). Spontaneous recovery was not obtained when extinction was overtrained (eight trials) and a 49-day retention interval was used (Experiment 4). However, saccharin intake at asymptote reached the level of baseline water intake, and not the highly preferred level shown by never-conditioned controls. Results of all four experiments suggest that extinction does not return an averted taste to the status of an unconditioned one. 相似文献
18.
Douglas C. Brooks Matthew I. Palmatier Eliseo O. Garcia Jessica L. Johnson 《Learning & behavior》1999,27(1):77-88
The effect of an auditory cue presented during extinction on spontaneous recovery of a conditioned taste aversion was investigated in three experiments. Experiment 1 demonstrated that the presence of the cue during extinction did not influence saccharin consumption during that phase, and that an aversion to saccharin in the absence of the cue was stronger at 18 days than at 1 day after extinction, representing spontaneous recovery rather than a renewal effect. Experiment 2 showed that a cue presented during extinction and testing reduced spontaneous recovery. Experiment 3 replicated that effect and showed that it depended on the cue’s correlation with extinction and not on an unconditioned effect; cues that had been presented during or prior to conditioning did not reduce spontaneous recovery when presented during testing. The cue’s potential to reduce spontaneous recovery through conditioned inhibition or configural cue learning is discussed, as is the possibility that the cue retrieves a saccharin extinction memory in a manner consistent with Bouton’s (1993) account of spontaneous recovery. 相似文献
19.
Retention of a brightness discrimination avoidance task by rats is impaired (Kamin effect) following a 1-h training-to-test interval (TTI), is enhanced after a 3-day TTI (reminiscence, or long-term spontaneous improvement), and is disrupted following a 21-day TTI (long-term forgetting). An exposure to the conditioned stimulus (CS), delivered 5 mm before a 1-h delayed retention test, not only compensated for the performance deficit that corresponds to the Kamin effect, but induced a large improvement in performance similar to that normally obtained after a 3-day TTI. It can be proposed that such cuing may act either by accelerating a natural memory-trace maturation process or by improving the retrievability of the memory trace. Since these possibilities lead to opposite predictions concerning the length of the facilitation induced by cuing, the effect of a pretest exposure to the CS on performance obtained during a 1-h delayed retention test was studied after several cuing-to-test intervals (0, 5, 10, or 20 min). The results, which indicate that cuing transiently enhanced subsequent retention performance, more convincingly support the retrieval hypothesis. The effects of pretest exposure to the CS (which occurred 5 min before testing) were also examined 10 min, 1 h, or 24 h after initial training. The results indicate that the facilitative effect of cuing obtained when retention performance was disrupted shortly after training (1-h TTI) was also obtained after a 24-h retention interval, in the absence of performance disruption. An interpretation of the facilitative effect of a pretest exposure to the CS is proposed, and implications concerning the memory trace are further discussed in relation to the multidimensional hypothesis. 相似文献
20.
Extensive extinction greatly reduces response rate and increases the relative frequency of short interresponse times, but
does not affect temporal learning or operant response rate. In each of two experiments, 24 rats were trained in a multiple
cued interval procedure with three stimuli (noise, light, and clicker) at three intervals (30, 60, and 120 sec). In Experiment
1, after 50 sessions of extinction, response rate decreased from about 25 to 0.5 responses/min, but temporal discriminations
were maintained and the initial response gradients in reacquisition had a pattern that corresponded with the original (rather
than current) training conditions. In Experiment 2, these results were replicated and extended by examination of the effect
of stimulus duration on response patterns during extinction, but its lack of effect on reacquisition. The similarity of the
initial performance in reacquisition to the asymptotic performance in acquisition was presumably due to the similarity of
context. The individual subject data may be downloaded from www.psychonomic.org/archive. 相似文献