共查询到20条相似文献，搜索用时 31 毫秒
1.
Rats were trained in a three-alternative spatial delayed matching-to-sample task in a starburst maze. Samples consisted of rewarded forced choices of one arm, and retention was indicated by rats’ returning to that arm after a 90-sec delay. If a rat made an error on its first choice, it was returned to the start compartment and allowed a second choice. Unlike in previous experiments with this task, all three arms were available during the animals’ second choices. The rats tended to perseverate in their second choices by returning to the arm that they had erroneously visited on their first choice. In Experiment 1, the accuracy of second choices following first-choice errors was below chance during the first block of sessions, when a 90-sec delay intervened between the first choice and the second choice, and at chance during the second block of sessions, when a short (5–6 see) delay intervened between first and second choices. In Experiment 2, long-delay and short-delay sessions were randomly presented to naive subjects. Similar results were obtained. In both experiments, the tendency to repeat the erroneous first choice was greater when long delays separated the two choices than when short delays were used. The results suggest that rats make their first-choice errors because they erroneously encode or remember the location of the sample and that they base their second choices on the same erroneous-memory. The increase in perseveration at long delays implies some kind of rehearsal-like mechanism that slows forgetting of the memory controlling the first choice. 相似文献
2.
R. A. Burns 《Learning & behavior》1976,4(4):473-479
Two experiments assessed the role of aftereffect learning in rats rewarded with sucrose solutions. In Experiment 1, rats were trained in a single straight runway for two trials on each of 18 days, each trial terminating with either large (20% scurose) or small (3% sucrose) reward. The ITI was 3–5 min. The sequence of daily rewards for each of four groups was small-small (SS), small-large, (SL), large-small (LS), or large-large (LL). Response patterning and a simultaneous negative contrast effect were observed in LS and SL relative to the consistently rewarded controls. During 10 massed extinction trials, resistance to extinction was greatest for Group SL, followed in order by Groups SS, LL, and LS. Experiment 2 examined single alternation of large and small rewards administered for 10 trials on each of 31 days with an ITI of 60 sec. Reward for one group was 20% or 3% sucrose while another received 1 or 10 45-mg Noyes pellets. Appropriate patterning developed only in the food-pellet rewarded animals. The overall results suggest that sucrose rewards may produce high-amplitude and long-duration aftereffects which interfere with learning in designs employing several massed daily trials, but which may facilitate learning—relative to food-pellet rewards—with longer intertrial intervals and fewer daily trials. 相似文献
3.
Larry W. Means 《Learning & behavior》1988,16(3):303-311
Independent groups of Sprague-Dawley rats were found to acquire a win-stay, but not a win-shift, escape resporse in a circular water maze in each of three experiments that varied with respect to swim time and distance prior to escape following an incorrect first choice. The subjects were given pairs of trials: an information trial and a test trial, separated by 10 min. On the information trial the camouflaged escape platform was randomly placed in one of two positions. On the test trial the platform was placed in the same position for the win-stay task and in the opposite position for the win-shift task. Animals that did not acquire either the stay or the shift response perseverated in their responses, consistently going to the same escape location first on both information and test trials. In the fourth experiment, in which win-shift, win-stay, and perseveration all led to escape, all rats perseverated in their responses. It was concluded that response perseveration and win-stay are more natural responses than win-shift for rats in a water escape situation. This finding contrasts with the spontaneous alternation and readily acquired win-shift behavior previously demonstrated in rodents in exploratory and appetitive situations. 相似文献
4.
Willson and Wilkie (1993) developed a novel procedure for assessing pigeons’ memory for the spatial location of food. Only one of four locations (consisting of an illuminated pecking key and grain feeder) provided food each day. Over days, different locations provided food. The pigeons’ tendency to revisit the location that was profitable on the previous day demonstrated memory for food-spatiallocation associations over a period of 24 h, retention longer than previously reported for this species. This basic finding was replicated and extended in three experiments. Experiment 1 demonstrated that location-food discriminations were also remembered well when established with successive rather than concurrent procedures. Experiment 2 demonstrated that pigeons can remember two location-food associations over 24 h. Experiment 3 showed that the discrimination training inherent in this paradigm is important for retention; retention was impaired when only the rewarded location was presented. Overall, this research suggests that cross-species differences in spatial memory performance may be due to quantitative rather than qualitative differences in the memory system underlying performance. 相似文献
5.
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
6.
Individual honeybees foraging at a laboratory window were trained with a correction method to choose between blue and yellow targets, one of which contained sucrose solution. There were two trials on each visit, with the locus of the sucrose predictable only on the second. Animals differentially rewarded on Trial 2 for choosing the rewarded color of Trial 1, for choosing the alternative color, or for choosing the target in the rewarded position of Trial 1 independently of its color, all showed a small but persistent preference for the rewarded color, with no significant preference for the rewarded position. When the positions of the colored targets were the same on Trial 2 as on Trial 1 (color and position confounded), there was a more substantial but equally persistent preference on Trial 2 for the rewarded color-position of Trial 1, whether the animals were differentially rewarded for perseveration or for alternation. The results provide further evidence of unlearned control of performance by short-term memory in honeybees but no indication of learned control. 相似文献
7.
Laura A. Hogarth William A. Roberts Shelley Roberts Benjamin Abroms 《Learning & behavior》2000,28(1):43-58
We performed six experiments in order to examine the ability of rats to use moving beacons and landmarks as cues to the location of reward on an eight-arm radial maze. In Experiments 1–4, the cues and goals were moved before each trial, and groups in which a single beacon was placed on the rewarded arm, a single landmark indicated that reward was on the arm immediately to the left of a landmark, or two landmarks were placed on each side of the reward arm were compared. The rats rapidly learned to track the reward in the beacon condition, failed to find the reward sooner than chance expectation with a single landmark, and did only slightly better than chance with two landmarks. In Experiments 5 and 6, the rats were trained in five trials per day, with the landmark and goal locations constant over daily rewarded trials, and in two extinction trials that were inserted among the rewarded trials. The rats found the goal arm at substantially better than chance expectancy with both one and two landmarks. Our results, in agreement with data from recent swimming pool experiments (A. D. L. Roberts & Pearce, 1998), show that rats will use the relationship between moving landmarks and a goal in order to find reward. 相似文献
8.
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
9.
Rats were runway trained on each of two, three-trial series consisting of different varieties of reward (X, Y, and Z) and nonreward (N) serving as trial outcomes. The two series are represented as XNY and ZNN. Distinguishing the two series were different brightness and texture cues on the runway floor. Transfer tests, conducted after the rats had developed faster running for rewarded trials than for nonrewarded trials and slower running on Trial 2 of ZNN than on Trial 2 of XNY, provided evidence that trial position, rather than item memories, was controlling the discriminations. In Experiment 1, reversing the floor cues completely reversed the discriminations. In Experiment 2, transfer to NNN did not change the routine patterns of approach that had been established. 相似文献
10.
In Experiments 1 and 2, honeybee foragers visiting the laboratory were fed on targets of two different colors, one containing 5 μl and the other containing 20 μl of 50% sucrose solution. The targets were presented singly in quasi-random sequences on the training visits, after which preference was measured in an unrewarded choice test. In Experiment 1, 16 differentially rewarded training trials with each color were followed by the same number of trials with the color-amount relation reversed; no preference for either color was found in the subsequent choice test. In Experiment 2, 20 differentially rewarded training trials with each color—enough to produce a clear preference for the 20-μl color when given directly after pretraining—were given after 10 feedings to repletion on each color that were calculated to generate near-asymptotic associative strength; no preference for either color was found in the subsequent choice test. In Experiment 3, there were 12 feedings to repletion on one color and, on the other, 12 feedings to repletion followed by 15 trials with a small (5 μl) reward; no preference was found in a subsequent choice test. The results of all three experiments support a nonrepresentational interpretation of the role of amount of reward in the learning of honeybees. 相似文献
11.
Pigeons were trained on a two-choice simultaneous discrimination (red vs. green) that reversed midway through each session.
After considerable training, they consistently made both anticipatory errors prior to the reversal and perseverative errors
after the reversal, suggesting that time (or number of trials) into the session served as a cue for reversal. In Experiment
2, to discourage the use of time as a cue, we varied the location of the reversal point within the session such that it occurred
semirandomly after Trial 10, 25, 40, 55, or 70. Pigeons still tended both to anticipate and to perseverate. In Experiment
3, we required 20 pecks to a stimulus on each trial to facilitate memory for the preceding response and sensitivity to local
reinforcement contingencies, but the results were similar to those of Experiment 2. We then tested humans on a similar task
with a constant (Experiment 4) or variable (Experiment 5) reversal location. When the reversal occurred consistently at the
midpoint of the session, humans, like pigeons, showed a tendency to anticipate the reversal; however, they did not show perseverative
errors. When the reversal location varied between sessions, unlike pigeons, humans adopted a win–stay/lose–shift strategy,
making only a single error on the first trial of the reversal. 相似文献
12.
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
13.
Charles I. Brooks 《Learning & behavior》1975,3(1):67-72
In Experiment I, rats which had received six partially reinforced runway acquisition trials, with a reward magnitude of 60 sec access to wet mash on rewarded trials, showed less persistent responding over highly massed extinction trials than subjects which had received the same acquisition schedule but reward magnitudes of either 1 or 10 45-mg pellets. In Experiment II, rats which had received six partially reinforced placements into one compartment of a two-compartment box, with 60 sec access to mash on rewarded placements, jumped a hurdle faster to escape nonreward than subjects which had received the same reward schedule but 10 45-mg pellets on rewarded trials. The data supported a primary frustration analysis for reward-magnitude manipulations within brief partial-reinforcement schedules. 相似文献
14.
Steven J. Haggbloom 《Learning & behavior》1980,8(3):424-428
In two differential conditioning experiments, groups of 10 rats each differed with respect to average reward and schedule of reward received in S+. Nonreward (N) occurred on all S? trials. In both experiments, extinction of responding to S? (resistance to discrimination) was extensively regulated by reward sequence and was largely independent of average reward. In Experiment 1, resistance to discrimination was a function of transitions from N to rewarded (R) trials (N-R transitions). In Experiment 2, resistance to discrimination was increased by large reward on the R trial of N-R transitions and decreased by large reward on the R trial of R-N transitions. These schedule effects on resistance to discrimination parallel the effects of comparable schedules on resistance to extinction following partial reinforcement. The results are discussed in terms of sequential theory, reinforcement level theory, and their implications for various schedule manipulations that have previously shown S? behavior to be inversely related to average reward in S+. 相似文献
15.
Scott H. Deibel Matthew L. Ingram Andrew B. Lehr Hiliary C. Martin Darlene M. Skinner Gerard M. Martin Isaac M. W. Hughes Christina M. Thorpe 《Learning & behavior》2014,42(3):246-255
It is difficult for rats to acquire daily time–place (TP) learning tasks. One theory suggests that rats do not use time of day as a stimulus signaling a specific response. In the present study, we tested rats’ ability to use time of day as a discriminative stimulus. A fixed-interval procedure was used in which one lever provided reinforcement on a FI-5-s schedule in morning sessions, and the same lever provided reinforcement on a FI-30-s schedule in afternoon sessions. Because only one place was used in this paradigm, the rats could only use time of day to acquire the task. Mean responses during the first 5 s of the first trial in each session indicated that the rats did not discriminate between the two sessions. In Phase II, a different lever location was used for each of the two daily sessions, which meant that both spatial and temporal information could be used to acquire the task. The rats readily acquired the task in this phase, and probe trials indicated that the rats were using a combination of spatial and temporal information to discriminate between the two different trial types. When the spatial cue was removed in Phase III, rats no longer discriminated the two sessions, suggesting that time can only be used as a discriminative stimulus when each daily session is associated with a distinct spatial location. 相似文献
16.
In seven experiments, an effect of the intertriai interval (ITI) duration on barpressing by rats was studied. A stimulus signaled a 15-sec variable-interval trial. The first response after the interval elapsed turned the stimulus off and was rewarded with food. Trials were separated by long (about 300 sec) or short (about 10 sec) ITIs. A within-subjects design established that response rate on trials after long ITIs was lower than that after short ITIs (Experiments 1 and 3–7). The effect was not cumulative (the effect of one and five consecutive short ITIs was the same). Response rate after short and long ITIs was the same when a between-subjects design was used (Experiment 2). Response rate was higher after 160-sec ITIs than after 300-sec ITIs, suggesting that the ITI duration at which all longer ITIs are treated the same (i.e., the upper limit) is greater than 160 sec (Experiment 3). When food, the trial stimulus, a novel stimulus, or a familiar stimulus never paired with food, was presented 10 sec before the next trial during some of the long ITIs, response rate on the next trial was similar to that found after 10-sec ITIs (Experiments 4–6). This similarity suggested that these events could mark the start of the ITI. However, the familiar stimulus did so only when it reliably predicted that the next trial would occur after a short interval. The effect of ITI duration on responding was apparently attributable to response latency. Response latency was greater after long ITIs, but once responding began, it was similar after long and short ITIs (Experiment 7). 相似文献
17.
Donald M. Wilkie 《Learning & behavior》1986,14(3):257-266
In the delayed matching of key location procedure, pigeons must remember the location of the sample key in order to choose correctly between two comparison keys. The deleterious effect of short intertrial intervals on key location matching found in previous studies suggested that pigeons’ short-term spatial memory is affected by proactive interference. However, because a reward expectancy mechanism may account for the intertriai interval effect, additional research aimed at demonstrating proactive interference was warranted. In Experiment 1, matching accuracy did not decline from early to late trials within a session, a finding inconsistent with a proactive interference effect. In Experiment 2, evidence suggestive of proactive interference was found: Matching was more accurate when the locations that served as distractors and as samples were chosen from different sets. However, this effect could have been due to differences in task difficulty, and the results of the two subsequent experiments provided no evidence of proactive interference. In Experiment 3, the distractor on Trialn was either the location that had served as the sample on Trialn ? 1 or one that had been a sample on earlier trials. Matching accuracy was not inferior on the former type of trial. In Experiment 4, the stimuli that served as samples and distractors were taken from sets containing 2, 3, 5, or 9 locations. Matching accuracy was no worse, actually slightly better, with smaller memory set sizes. Overall, these findings suggested that pigeons’ memory for spatial location may be immune to proactive interference. However, when, in Experiment 5, an intratrial manipulation was used, clear evidence of proactive interference was found: Matching accuracy was considerably lower when the sample was preceded by the distractor for that trial than when it was preceded by the sample or by nothing. Possible reasons why interference was produced by intratrial but not intertrial manipulations are discussed, as are implications of these data for models of pigeons’ short-term spatial memory. 相似文献
18.
Michael F. Brown Elizabeth Digello Michelle Milewski Meredith Wilson Michael Kozak 《Learning & behavior》2000,28(3):278-287
Rats searched for food hidden on top of poles in a 4 × 4 matrix of poles. Before each trial, the location of the four baited poles was unpredictable. However, the poles were always baited in one of two spatial patterns, either a square or a line. The food hidden on the four baited poles was one of two types, and the food type determined the identity of the pattern. Thus, once one baited pole was discovered, the food type provided a cue for the spatial pattern in which the remaining food was hidden. The results showed that rats learned the two spatial patterns in which the food was hidden and used the conditional cue to determine which pattern was relevant on individual trials, thereby increasing the efficiency of spatial search. 相似文献
19.
Control of pigeons’ keypecking by conditionalities in the spatial arrangement of two element stimuli (designated A and B) was investigated. In Experiment 1, reinforcement for keypecking was made conditional upon the left-right location of A and B: Reinforcement was available when A was on the left and B was on the right (AB), but not on BA, AA, or BB trials. The pigeons successfully discriminated the rewarded AB configuration, but only after a stage in which a particular element in a particular location (e.g., A on left) primarily controlled pecking. Experiments 2 and 3 systematically replicated these findings and included controls to discount discrimination of the AB compound on the basis of the temporal order (e.g., A followed by B) rather than the spatial configuration of the elements. During a generalization test in Experiment 4, the elements were presented singly either in the left (AX, BX) or right (XA, XB) positions. As would be expected had the animals learned “A on the left, B on the right is rewarded,” responding on AX trials exceeded that on XA trials, and responding on XB trials exceeded that on BX trials. 相似文献
20.
We conducted three experiments to investigate the associative structure underlying the reinstatement of instrumental performance
after extinction. In each experiment, rats were initially rewarded on two responses with different outcomes. At test, both
responses were extinguished in order to assess the impact of a single noncontingent outcome delivery on response selection.
Experiment 1 found evidence of outcome-selective reinstatement (i.e., more responses were performed on the lever that was
trained with the reinstating outcome than on the other lever). Experiment 2 demonstrated that the outcome’s capacity to reinstate
performance was not affected by a reduction in its motivational value. Experiment 3 found evidence that the reinstating outcome
selectively retrieved the response it signaled rather than the response it followed during training. Together, these findings
are consistent with the view that instrumental reinstatement depends on the discriminative stimulus properties of the reinstating
outcome. 相似文献