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1.
After receiving events in a fixed order, A-B-C…, rats, like people, on being provided with A, may anticipate not only B, a current anticipation, but also C, a remote anticipation. In two experiments, we attempted to determine whether rats’ remote anticipations are mediated by item cues (C elicited by A) or by position cues (C directly elicited by Position 3 cues, which generalize to Position 2). In Experiment 1, rats in a runway received two series of three trials, XNY and ZNN, each in irregular order each day. N signified nonreinforcement; X, Y, and Z signified three qualitatively different food reinforcements. The rats manifested a remote anticipation by running faster on Trial 2 in the XNY series than in the ZNN series. Since the series were presented irregularly, Trial 2 performance cannot be explained on a positional basis alone. It can be explained on an item basis, by assuming that the memory of the Trial 1 reinforcer became associated not only with the Trial 2 event, but with the Trial 3 event as well. Thus on Trial 2 the memory of X signaled N and Y, whereas the memory of Z signaled N and N. Experiment 2 produced the same results, regardless of whether the XNY and ZNN series were presented in regular or irregular order. These results indicate that remote anticipations can be mediated by item associations. They offer no evidence that position associations can do the same, but they do not rule out that possibility. 相似文献
2.
Rats learned an ordered RNR/RNN serial pattern task in a T-maze where they were shifted to a different runway on Trial 3 only
in the RNR series (shift-win/stay-lose group) or only in the RNN series (stay-win/shift-lose group). The shift-win/stay-lose
group developed faster speeds on Trial 3 of the RNR than on Trial 3 of the RNN series more easily than the stay-win/shift-lose
group. This difference occurred whether all rats were forced onto the same runway on the first two trials (Experiment 1) or
onto a different runway on Trial 2 from that on Trial 1 in each series (Experiment 2). Posttraining probe tests revealed that
the shift-win/stay-lose group in each experiment relied on the runway shift event in Trial 3 or on the series position to
anticipate the second reward within a series. Such reward expectancies were greater when the runway shift occurred in the
same series position as during training. These probe tests revealed that the stay-win/shift-lose group relied only on the
series position in Experiment 2. Our findings do not support predictions based on an associative predictive validity model.
Rather, they reflect rats’ predisposition to spontaneously alternate choices in the T-maze, a tendency corresponding to their
inherent win-shift foraging strategy. Rats in each group also reduced their speeds less on the nonrewarded Trial 2 when it
preceded a rewarded rather than a nonrewarded Trial 3. This effect suggests that rats were able to determine which series
contained a second rewarded trial. We discuss the theoretical implications of this Trial 2 speed effect in terms of rats’
uncertainty about where this second rewarded trial might occur in the RNR series. 相似文献
3.
Rats were exposed to three-trial series consisting of reinforced (R) trials and one nonreinforced (N) trial in a fixed order,
RRN and RNR (Experiments 1 and 2) or NRR and RRN (Experiment 3), on extended visually distinct runways in a T-maze. When initially
presented with the same sequence on each series in a session (separate presentations) with the same runway on all trials within
a series (Experiments 1 and 3), all the rats developed slower running speeds on N than on R trials. When a runway was sometimes
changed between the first and next two trials during separate presentations training (Experiment 2) or both sequences were
later intermixed within each session in each experiment, only rats exposed to each sequence on a specific runway maintained
these serial running patterns. Rats displayed serial running patterns on a test RNN sequence similar to that on the RNR sequence
(Experiment 2), as would be predicted by an intertrial association model of serial pattern learning (Capaldi & Molina, 1979),
but responded on test RRR and NRN sequences (Experiment 3) as would be predicted by an ordinal-trialtag/intratrial association
model (Burns, Wiley, & Payne, 1986). Results from test series of free-choice trials in Experiments 1 and 2 failed to support
a prediction of the intratrial association model that these rats would integrate RRN and RNR sequences. Rather than always
selecting a baited runway on both the second and the third free-choice trials, the rats only selected a baited runway on the
third trial on the basis of their choice on the second trial, as would be predicted by the intertrial association model. Only
after experiencing all possible outcome sequences during forced-choice training in Experiment 3 did these rats predominantly
select a baited runway on every free-choice trial. 相似文献
4.
Rats received three-trial series on a T-maze consisting of extended visually distinct left-black and right-striped side runways.
During the first phase of training, when allowed to select baited runways within these series, they predominantly alternated
their choices. During the second phase, rats received forced-choice serial pattern training of series consisting of two rewarded
(R) trials and one nonrewarded (N) trial in two fixed orders, RRN and RNR. In Experiment 1, the rats in the runway shift rule
group always received the second R trial when forced down a runway opposite that on the preceding trial in the series and
the N trial when forced down the same runway. The rats in the runway stay rule group always received the second R trial when
forced down the same runway and the N trial when forced down the opposite runway. In Experiment 2, each rat was conditionally
trained with both runway outcome rules as determined by the central alley lighting and the type of food in the side alleys.
The rats took longer to reduce their running speed on the N trial within each sequence under the runway stay rule than under
the runway shift rule. They also took longer to acquire serial pattern responding for the RNR than for the RRN series only
under the runway stay rule condition. When subsequently reexposed to series of free-choice trials on the final phase, rats
maintained spontaneous alternating choice patterns under the runway shift rule conditions but either seldom alternated their
choices (Experiment 1) or greatly reduced choice alternations (Experiment 2) under the runway stay rule condition. We discussed
these effects in terms of rats’ natural foraging strategies and as a factor that interacts with other within- and between-series
variables that affect serial pattern behavior. 相似文献
5.
In each of two investigations, rats ran in a runway to obtain varying quantities of food pellets presented in a fixed order, such as 20-0-20. The major finding was that rats ran faster on a 0-pellet trial if that trial was followed shortly by a 20-pellet trial (e.g., 20-0-20 series) than if it was not (e.g., 20-0 series). This finding was obtained both within groups (Experiment 1) and between groups (Experiment 2), and suggested that the memory of 20 pellets arising from the first trial of the 20-0-20 series was retrieved not only on the second trial of the series, thereby signaling 0 pellets, but on the third trial as well, thereby also signaling 20 pellets. Retrieving the memory of 20 pellets on Trial 3 of the 20-0-20 series apparently resulted in that memory’s elevating speed on Trial 2 of that series. 相似文献
6.
Steven J. Haggbloom 《Learning & behavior》1983,11(3):367-372
In two experiments, rats were trained on a successive go/no-go discrimination problem in the runway in which the positive (S+) and negative (S?) discriminanda were differentiated by the presence or absence of a distinctive feature. The feature in Experiment 1 was a series of flashing lights over the runway. In Experiment 2, the feature was a pretrial reinforcement (Phase 1), or pretrial reinforcement versus pretrial nonreinforcement (Phase 2). The feature signaled S+ trials in feature-positive (FP) groups and S? trials in feature-negative (FN) groups. The original discrimination was reversed in Phase 2 of both experiments. With the exception of the pretrial nonreinforcement groups in Experiment 2, there was an asymmetry in discrimination learning in both phases of both experiments favoring superior discrimination learning by FN subjects over FP subjects, a feature-negative effect. Implications of the results for an information processing account of asymmetries in learning feature discriminations are discussed. 相似文献
7.
Delayed simple discriminations are typically retained more accurately over longer delays by pigeons than are delayed conditional discriminations (e.g., Honig & Wasserman, 1981). In two experiments, we investigated the extent to which trial outcomes contribute to this difference by comparing performances when all trials ended with food reinforcement versus when only half of the trials did. Experiment 1 showed that when food was presented on all trials, contingent upon either pecking or not pecking the test stimulus, levels of retention and rates of forgetting were comparable for these two tasks. By contrast, Experiment 2 showed better retention of delayed simple than delayed conditional discriminations when half of the trials ended with food and the other half in extinction. Furthermore, delayed simple discriminations were retained more accurately with food versus no-food outcomes than with food at the end of every trial, whereas the reverse was true for delayed conditional discriminations. These findings indicate that retention differences between these tasks are another instance of the differential outcomes effect. 相似文献
8.
Lower order units combined into higher order functional units (e.g., letters into words) are calledchunks. The hypothesis tested here suggests that chunks are formed when memories of goal events signal other goal events, a signal capacity that can be reduced when memories are seriously overshadowed by other more valid cues calledgrouping cues. In support of this hypothesis, it was found, in each of three experiments employing rats in runways, that the capacity of the memory of nonreward to signal reward depended on its validity relative to that of two other situational cues, runway brightness cues and a change in brightness cues, from one trial to the next. Specifically, the capacity of the memory of nonreward to signal reward was much more seriously reduced when it was in competition with more valid situational cues (.33 vs. 1.00, Experiment 1; .50 vs. 1.00, Experiment 2) than when it was in competition with situational cues having either the same validity (.33, Experiment 1) or a slightly higher validity (.33 vs. .50, Experiment 3). It was also found that grouping each of two series was less effective in producing chunking than was grouping only one of the series. 相似文献
9.
E. J. Capaldi Donna R. Verry Timothy M. Nawrocki Daniel J. Miller 《Learning & behavior》1984,12(1):7-20
Two experiments indicated that two approaches to serial learning are too extreme—the classical view that it consists only of interitem associations and various recent views that it involves no interitem associations. The novel assumption introduced here was that phrasing cues, normally conceptualized as merely segregating long series into smaller units or chunks, may also enter into associations with items, thereby reducing interitem interference and facilitating serial learning. It was found that one item could become a signal for another item, an interitem association, or be overshadowed by a phrasing cue, such as a brightness and temporal cue, also signaling that item. The items were .045-g pellets. Rats traversed a runway for items arranged in ordered series, 14-7-3-1-0 pellets (Experiment 1) or 10-2-0-10 (Experiment 2). Complete tracking of, for example, the 10-2-0-10 series would consist of fastest running to 10 pellets and slowest running to 0 pellets. In both investigations, the interitem association overshadowed was that between 0 pellets and the subsequent rewarded item, 0 → 14 (Experiment 1) or 0 → 10 (Experiment 2). Either repetitions of the 14-7-3-1-0 subpattern (Experiment 1) or merely the terminal 10-pellet item (Experiment 2) were phrased, both methods producing identical results. Overshadowing the 0-pellet item produced superior serial learning, more rapid extinction, and, in Experiment 1, considerable elevation of responding when the brightness phrasing cue was introduced in extinction, an effect said to be conceptually identical to spontaneous recovery and one demonstrating directly that phrasing cues are in reality overshadowing cues. It was suggested that many effects attributed to forgetting may be due to unrecognized overshadowing of memory cues by phrasing cues, giving rise to exaggerated estimates of forgetting. 相似文献
10.
In two experiments, rats traversed a runway in the presence of odor cues from odor-donor rats (stimulus odor). These odors were established in the start and run sections of a runway. As in previous work, these odors were shown to be influential determinants of behavior There is an indication that odors of reward and nonreward may be different for different rats, and that these different odors can be used to form complex discriminations. 相似文献
11.
The degree to which rats and monkeys base their discriminations of complex auditory stimuli (“tunes”) on frequency contours rather than on local features was investigated. In Experiment 1, groups of rats and monkeys trained with tunes as S+ and S? acquired a simple operant discrimination no faster than groups that received the same notes of each tune but in a new random order on each trial; neither did the groups differ on two transfer tests devised to detect learning of frequency contour in the tune-trained animals. Acquisition in the tune-trained and random-notes groups seemed to be based on the overall frequency difference between S+ and S?, which was about 1.5 octaves. In Experiment 2, S+ and S? were similar to each other with regard to overall frequency and individual notes, the most salient differentiating characteristic of the tunes being their tonal pattern. The tune-trained groups were clearly superior to the random-notes animals in acquisition, and an initial transfer test suggested that the former might have learned the discrimination on the basis of frequency contour. However, the detailed transfer tests of Experiment 3 strongly suggested that the tune-trained rats and monkeys based their discriminations primarily on local cues rather than on frequency contour. Based on the results of Experiment 4, the data of an earlier study that suggested frequency contour learning in monkeys and rats were reinterpreted in terms of control by local cues. 相似文献
12.
In Experiment 1, a group of rats were runway trained on each of two reward series for 32 days. The two series consisted of three runs, the first two of which were, respectively, rewarded and nonrewarded; the third run was rewarded in one series but nonrewarded in the other. A 40-min interval separated the two series; the first and second runs within the series were separated by a 10-min interval, whereas the second and third runs were separated by a 30-sec interval. The reward (and nonreward) events and temporal cues of the two series are designated R-NR/R-NN. A second group was similarly trained, with the exception that the 10-min interval separated the second and third runs (RN-R/RN-N). Both groups developed appropriate differential running on the third run of the two series, and the RN-R/RN-N animals ran appropriately (slowly) on the second run of both series. Appropriate Run 2 performance appeared in one half of the R-NR/R-NN animals (depending upon order of series presentation); the remaining half ran faster on Run 2 of the R-NR series than on the same run of the R-NN series, an effect currently termed interevent anticipation. A cue shift phase in which all within-series intervals were 30 sec showed that the temporal intervals were controlling performance before the shift. Experiment 2 showed that interevent anticipation appears when all within-series intervals are either 10 min or 30 sec from the beginning of training, suggesting that the elimination of interevent anticipation in Experiment 1 was due to the differential cuing of runs by the temporal intervals rather than the particular interval duration. The overall findings suggest that the similarity of Run 2 and Run 3 performance termed interevent anticipation may be due to a failure to discriminate the ordinal position of runs within a series. 相似文献
13.
The greater the dissimilarity between exteroceptive stimuli, the easier it is to discriminate between them. To determine whether a similar relationship holds for memories produced by reward events, rats in three runway investigations received trials in pairs, the number of food pellets (0.045 g) occurring on Trial 1 indicating whether reward or nonreward would occur on Trial 2. In each investigation, discriminative responding on Trial 2 was better the larger the difference in reward magnitude on Trial 1. This finding was obtained under a wide variety of conditions: for example, when the larger of two reward magnitudes on Trial 1 signaled nonreward on Trial 2 (Experiment 1, 10 vs. 2 pellets); when the smaller of two reward magnitudes on Trial 1 signaled nonreward on Trial 2 (Experiment 2, 10 vs. 2 pellets); and when the same magnitude of reward on Trial 1 signaled nonreward on Trial 2 (Experiment 3, either 5 pellets or 0 pellets). The findings obtained here indicate that the greater the dissimilarity between reward magnitudes, the greater the dissimilarity between the memories they produced and, thus, the easier it is to discriminate between them. It is suggested that the present results may provide a basis for understanding findings obtained in other instrumental learning investigations in which reward magnitude is varied. 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 influence of cue type and cue configuration on radial-maze performance in rats was examined in two experiments. In the first experiment, it was found that rats provided with both salient intramaze and extramaze cues acquired the task faster than rats given only one set of cues. No difference in acquisition was found between a group trained with intramaze cues alone and a group trained with extramaze cues alone. In a cue-preference test, it was found that groups that had been trained with extramaze cues, intramaze cues, or both sets of cues relied on extra-maze cues to avoid visited arms when given both types of cues concurrently. When all groups were transferred to intramaze-cue-alone trials, only the group that had been originally trained with extramaze cues alone showed any disruption. Also, during the second half of the intramaze-cue-alone trials, the arrangement of these cues was randomly changed on each trial. This disruption in cue configuration did not deleteriously affect performance in any of the three groups; all remained above chance performance, although the performance of the group originally trained with extramaze cues alone was inferior to that of the other two groups. In Experiment 2, groups of rats were trained on daily alternating trials under intramaze-cue-alone and extramaze-cue-alone conditions. For one group, the configuration of intramaze cues was altered randomly on each trial; the other group had intramaze cues always presented in the same configuration over trials. It was found that acquisition was more rapid on intramaze trials in the group given static configurations. Also, acquisition of the extramaze task was faster than the intramaze task in the group given variable intramaze cue configurations. No difference was found between the intramaze and extramaze conditions in the group given static intramaze cue configurations. These data suggest that a static cue configuration may influence radial maze performance, but is not a necessary condition for such performance. 相似文献
16.
In four experiments, rats were trained on different patterning discriminations before being tested with compounds composed of novel combinations of the trained stimuli. In Experiment 1, rats were trained on a negative-patterning schedule (A+ B+ AB-) intermixed with reinforced presentations of a second compound (CD+). On a subsequent test, the rats responded more to two novel compounds, AC and BD, than to A and B, but less than to CD. In Experiment 2, rats were trained on two concurrent negative-patterning discriminations (A+ B+ AB-, C+ D+ CD-). On test, they responded more to AC and BD than to AB and CD, but less than to the single stimuli. In Experiment 3, rats were trained on two concurrent positive-patterning discriminations (A-B- AB+, C- D- CD+). On test, their response rates to AC and BD were not different from the response rates to the trained compounds (AB and CD). Finally, in Experiment 4, rats were trained on a positive- and negative-patterning discrimination concurrently. Once again, on test, response rates to AC and BD were not different from responding on reinforced trials of the trained discriminations (A+, B+, and CD+). We discuss the implications of these findings for elemental and configural models of stimulus representation. 相似文献
17.
Tuan D. Tran Laura C. Adducci Liza D. DeBartolo Beth A. Bower Eugene R. Delay 《Learning & behavior》1994,22(4):421-426
Cross-modal transfer of learning between black/white and rough/smooth discrimination tasks was studied in a two-choice maze procedure in which the stimuli for both discriminations were located on the floor of the maze. Rats were trained initially with cues of one modality and then given transfer training with cues of the second modality. The amount of transfer produced by two criteria of learning, 9 correct responses in 10 trials and 18 correct responses in 20 trials, was also studied. Bidirectional cross-modal transfer of learning was demonstrated more clearly with the more stringent learning criteria. These positive transfer effects appeared primarily to be the result of general transfer processes. 相似文献
18.
In these experiments, each rat received two different series of three runs each. The lone group in Experiment 1 received the series 10-0-10 and 10-0-0, where, for example, 10-0-10 means that the rat received three discrete runs (in a runway) that terminated in 10, 0, and 10 pellets, respectively. In Experiment 2, the series were 20-0-0 and 0-0-20 for one group and 20-0-20 and 0-0-0 for another. Of primary concern in both experiments was the rat’s anticipation, as measured by running speed, of 0 pellets on the middle, or second, run of each series. In each experiment, running speed to this 0-pellet event was independent of reinforcement magnitude on the first run of each series and was greater, the greater the reinforcement magnitude on the third run of each series. These results indicate that on the second run of each series the rat was anticipating not merely the 0 pellets associated with that run (intraevent anticipation), but also the reinforcement magnitude associated with the future, third run of each series (interevent anticipation). These results are shown to be consistent with an S-S cognitive view of anticipation and inconsistent with an S-R serial-chaining view of serial learning. 相似文献
19.
C B Fisher 《Child development》1979,50(4):1088-1092
Some have interpreted children's reliance on external visual cues as evidence that they are unable to use internal cues for orientation. This hypothesis was examined in experiment 1, where 24 preschoolers were tested on left-right, vertical-horizontal, and mirror-image oblique discriminations under essentially context-free conditions. Subjects succeeded on all discrimination problems and performed equally well on vertical-horizontal and mirror-image oblique discriminations. Thus, preschoolers can use an internal frame of reference to code orientation. Experiment 2 contrasted children's performance under context-free conditions with their ability to discriminate orientation in the presence of external visual cues. Children who had discriminated left-right oblique and nonoblique mirror-image forms in experiment 1 failed to so discriminate in experiment 2. This result is discussed in terms of a breakdown in the ability to use internal cues when external visual cues are available. 相似文献
20.
We used a familiarization-novelty procedure to determine whether 4 infant chimpanzees spontaneously perceive the sameness of and the difference between both concrete objects and relations between objects. In Experiment 1, a single object was presented on the Familiarization Trial 1 and the animal's looking time recorded. On the Test Trial 2, an object was presented that was either identical to or different from that shown on Trial 1. Looking times on Test Trial 2 were less when the same item had been presented on the preceding familiarization trial. Novel items on Trial 2 were attended to longer, indicating that the infant chimpanzees perceived concrete objects were either the same or different. In Experiment 2, a single pair of objects was presented on the Familiarization Trial 1, and handling time was measured. The objects in a pair were either the same or different (e.g., AA vs. CD). On the Test Trial 2, a new object pair (e.g., BB vs. EF) was presented that instantiated either the relation shown on Trial 1 or the alternative relation. Handling time on Trial 2 was influenced by the relation instantiated on Trial 1. Handling times on Test Trial 2 were less when the identical relation had been presented on the preceding familiarization trial. Novel relations on Trial 2 were attended to relatively longer. This result indicates that infant chimpanzees perceive similarities and differences between abstract relations as well as between concrete objects. That is to say, they perceived relations between relations in Experiment 2. Despite this ability to perceive both concrete and abstract "same/different" relations, the same chimpanzees subsequently failed to use the latter knowledge in a matching-to-sample task in Experiment 3. Although they successfully matched single objects, they were unable to match object pairs instantiating the same relation (e.g., if AA then match BB; if CD then match EF). These results contradict claims that failure to learn an instrumental discrimination involving abstract relations reflects an inability to detect such relations. In every species there may be a disparity between the ability to perceive spontaneously a property of the world and the ability to use the concept instrumentally. 相似文献