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1.
Treatments that interfere with animals’ short-term retention (e.g., in delayed matching-to-sample) were studied using a spatial memory task. Rats performed in an eight-arm radial maze in which choosing each arm without repetition was the optimal behavior. Performances were interrupted between fourth and fifth choices for a delay of 15 sec to 2 min. A variety of events occurring during the delay interval did not disrupt memories for prior choices (as assessed by the accuracy of postdelay choices). The ineffective treatments included variations in visual and auditory environments, removal from the maze, food consumed during the delay, a distinctive odor added to the maze, or combinations of these manipulations. Additionally, performance on another spatial task (a four-arm maze) during the delay between Choices 4 and 5 did not interfere with performance in the eight-arm maze. These findings suggest that rats’ memories for spatial locations are immune to retroactive interference, at least within the range of conditions reported, and that the rat can successfully segregate memories for spatial locations established in different contexts. 相似文献
2.
In the present study, we examined the effects of extinction of sucrose-predictive contextual cues and/or sucrose satiation on the expression of sucrose cue reactivity in a rat model of relapse. Context extinction was imposed by housing rats in their home cage or in the operant conditioning chamber for 17 h prior to testing. For sucrose satiation, rats were allowed unlimited access to water or sucrose for 17 h prior to testing. Cue reactivity was assessed after either one (Day 1) or 30 (Day 30) days of forced abstinence from sucrose self-administration. An abstinence-dependent increase in sucrose cue reactivity was observed in all conditions (“incubation of craving”). Context extinction dramatically reduced lever responding on both Day 1 and Day 30. Sucrose satiation had no significant effect on cue reactivity in any condition. These results demonstrate that the context in which self-administration occurs maintains a powerful influence over cue reactivity, even after extended forced abstinence. In contrast, the primary reinforcer has little control over cue reactivity. These findings highlight the important role of conditioned contextual cues in driving relapse behavior. 相似文献
3.
Rats experienced a spatial pattern of baited and unbaited arms in an eight-arm radial maze. The spatial pattern remained constant
over trials, but the spatial locations that were baited varied unpredictably. Although there was no evidence of control by
the spatial pattern during free choice training trials, the rats’ ability to locate baited arms in forced choice test trials
was superior to that of animals in a control condition for which maze arms were not baited in a consistent spatial pattern.
This is consistent with the results of experiments showing that spatial choices by rats in a pole box maze are controlled
by abstract spatial patterns. 相似文献
4.
Social memory was investigated in the context of a spatial working memory task. Pairs of rats were tested in an eight-arm
radial maze. Under most conditions, there was a tendency to choose maze locations that had been visited earlier by the other
rat. The possibility that this tendency is produced by common preferences for particular maze locations was ruled out. An
opposite tendency to avoid visits to locations that had been visited earlier during the trial by another rat was found only
when the maze location contained two pellets (rather than an undepletable supply), the rats’ ability to see each other in
the maze was restricted to the central arena, and the maze location had been previously visited by the focal rat. The amount
of food available in maze locations did not otherwise modulate social influences on spatial choice. The results indicate that
memory for a rat’s own previous choices is combined with memory for the choices made by another rat. 相似文献
5.
Edward A. Wasserman 《Learning & behavior》1973,1(3):198-206
Three experiments investigated the effect of contextual and trial stimulus lighting conditions on keypeck autoshaping in pigeons. White illumination of a response key before food presentation readily produced keypecking in a brightly lit chamber but failed to do so in a chamber without house illumination (Experiments I and III). Keypecking in a darkened cubicle progressively increased and the facilitatory effect of a houselight decreased as the keylight stimulus was varied from a color change (Experiment II) to a feature change (Experiment III). These findings support a “cue localization” hypothesis of autoshaping. according to which reinforcement signals select specific behaviors for expression and direct these behaviors toward the source of stimulation. This account was extended to superstitious and operant conditioning situations. 相似文献
6.
Rats (n=4) searched for food on an eight-arm radial maze. Daily 56-min sessions were divided into eight 7-min time zones, during
each of which a different location provided food; locations were randomized across subjects before training. The rats obtained
multiple pellets within each time zone by leaving and returning to the correct location. Evidence that the rats had knowledge
about the temporal and spatial features of the task includes the following. The rats anticipated locations before they became
active and anticipated the end of the currently active locations. The rats discriminated currently active locations from earlier
and forthcoming active locations in the absence of food transition cues. After the rats had left the previously active location,
they visited the next correct location more often than would be expected by chance in the absence of food transition cues.
The rats used handling or opening doors as a cue to visit the first location and timed successive 7-min intervals to get to
subsequent locations. 相似文献
7.
The effects of food reward on rats’ behavior in radial and Dashiell tunnel mazes were examined in two experiments. In the first, with animals at ad-lib body weights, food reward reduced speed of movement at the food locations, but did not affect the patterns of movement in either maze. Exploratory efficiency in the Dashiell maze was unaffected by food reward, and spontaneous patrolling of the radial maze by the nonrewarded animals was comparable to the behavior, reported by others, of rats running for food reward on elevated eight-arm mazes. In the second experiment, with subjects maintained at 80% of ad-lib body weights, there was some evidence for “winstay” learning: food-rewarded rats in the Dashiell maze were relatively more active near the food locations than were the nonrewarded animals, and more rewarded than nonrewarded rats revisited all food locations in the radial maze. Nonetheless, exploratory efficiency in the Dashiell maze was unaffected by food reward, as was patrolling efficiency in the radial maze, which was again comparable to that of rats on elevated mazes. The similarity in behavior of rewarded and nonrewarded animals in these mazes implies that the major determinant of their behavior, whether or not food reward is provided, is a spontaneous tendency to avoid places recently visited. 相似文献
8.
In a series of four experiments, the effects of the reactivation of an old memory in different states of vigilance were investigated. Rats were trained to run in a six-unit spatial discrimination maze for food reward with low-level electrical stimulation delivered to the ear when they entered blind alleys. Twenty-five days after training, electrotactile stimulation was given to animals as a reactivating treatment just before a retention test. When the cuing treatment was given during wakefulness, retention performance was improved. When it was given in slow-wave sleep, it had no effect. When it was given in paradoxical sleep, performance was poorer. The use of control groups permitted an assessment of the specificity of the cuing effect in each case: Pretest presentation of the same stimulus did not modify performance when it had no cue value. Together, these results show that the effect of the reactivation of an old memory depends upon the vigilance state in which reactivation takes place. They suggest that reorganization of an old memory could be accomplished during paradoxical sleep. 相似文献
9.
Rats were trained over a number of sessions on an eight-arm radial maze with eight trials on each session. Each of four arms on the maze contained a different pattern formed by sequences of reward (two pellets) or nonreward (no pellets) over successive trials within sessions. The patterns were single alternation, double alternation, and two patterns in which four rewards or four nonrewards were preceded and followed by two nonrewards or two rewards, respectively. The other four arms on the maze served as control arms and always contained one pellet. It was found that rats tracked all of these patterns when they were required to climb over barriers to enter and leave arms. However, rats showed no ability to extrapolate patterns beyond the training trials. These findings, and a further analysis of arm-choice stereotypy, led to the conclusion that rats tracked by using a trial-number strategy. 相似文献
10.
John D. Batson Michael R. Best Deborah L. Phillips Hemlata Patel Kevin R. Gilleland 《Learning & behavior》1986,14(3):241-248
Thirsty rats were trained to collect small water rewards from the end of each arm of an eight-arm radial maze. During these training trials and subsequent testing trials, the subjects were allowed to choose a maximum of eight arms. “Preference” for a target maze location was studied by noting when, in the sequence of eight choices, the target was selected. During testing, when one maze location was consistently devoid of water, rats decreased their preference for this arm over trials (Experiment 1). Similarly, rats that learned a saccharin-lithium association demonstrated lower preferences for a maze location that consistently held the conditioned saccharin solution. This was true for animals that received saccharin-lithium conditioning on the maze (Experiment 3A) and for animals conditioned to saccharin in a separate context (Experiment 3B). An increase in preference for a target maze location consistently containing a sweet chocolate milk solution was observed in animals that were water- and food-deprived (Experiment 2). These studies demonstrate that animals will modify their responses toward (preferences for) maze locations that predictably contain an altered reward. 相似文献
11.
Rats were trained to leverpress in a conventional operant test chamber; however, their behavior was rewarded solely by social interaction with a human being. This training was successful for half the subjects tested; success was confined to animals for which social interaction had occurred prior to training. Similar findings with other species are discussed. Although the effects of social interaction with a human are by no means as robust as those of food to a hungry animal, the present results suggest that the human-rat interaction may be a positive adjunct to conventional behavioral training techniques, and a possible confound where its effects are uncontrolled. 相似文献
12.
Rats were given three stages of training on an eight-arm, elevated radial maze with food reward at the end of each arm. In Stage 1, rats were allowed to choose freely among the arms from the beginning of a trial. In Stage 2, three initial forced choices were followed by a series of free choices. In Stage 3, the central platform of the maze was rotated with the rat on it between the initial forced choices and the free choices. Following testing on these three stages, the animals were divided into four groups and deprived of selected senses. One group was made blind, a second anosmic, a third blind and anosmic, and a fourth was left normal. The same three stages of testing that had been conducted preoperatively then were run again post-operatively. Throughout these tests, the possible use of auditory cues was tested by presenting white noise on alternate trials. Finally, two further tests were carried out, the multiple rotations test and the removal-replacement test. The results indicated that visual cues, but not olfactory or auditory cues, played a critical role in the rat’s ability to avoid previously entered alleys. There was evidence also that rats used internal cues from kinesthetic and/or vestibular receptors when visual cues were absent. 相似文献
13.
Rats were trained in a two-lever operant chamber to discriminate the presence versus the absence of a drug. During drug sessions, the training procedure involved reinforcing presses on lever 1 with saccharin-sweetened water but not reinforcing presses on lever 2. During no-drug sessions, only presses on lever 2 were reinforced. After this discrimination was learned, each rat was trained to discriminate presence versus absence of a second drug. All rats learned this second discrimination. Finally, the rats were tested to determine whether they could still discriminate the first drug, as well as other pharmacologically related compounds; most rats could. Training drugs were phenobarbital 30–35, nicotine 0.4, amphetamine 0.4, cyproheptadine 7, phencyclidine 4, cyclazocine 1.5, fentanyl 0.04, and scopolamine 0.2 mg/kg. The results indicate that drug versus no-drug discrimination training does not disrupt discriminative control previously established with a different drug. When considered in combination with the results obtained during substitution tests conducted after drug-versus-no-drug training, the data suggest that, instead of discriminating drug cues versus no-drug cues, rats discriminate presence versus absence of particular drug cues. 相似文献
14.
William S. Maki 《Learning & behavior》1975,3(4):312-316
In a study of sustained attention (“vigilance”), pigeons performed a conditional discrimination in a 3-key operant chamber. Pecking a white center key initiated a 0.2- or 2.0-sec cue (a red or green disk). The side keys then displayed white disks, and a peck on the right or left key was reinforced depending on whether the preceding cue was red or green. Pecks on the white center key initiated the cue according to one of two schedules of cue production (FR 1 or VI 7.5 sec). Control of side key choices by 0.2-sec cues was disturbed by transition from FR 1 to VI 7.5, and recovered after the schedule of cue production changed from VI 7.5 back to FR 1. Control of choices by 2.0-sec cues was not affected by changing schedules of cue production. Rates of pecking the cue were higher than rates of cue-producing responses. 相似文献
15.
Many researchers have used the controlled procedures of operant methodology to test the predictions of foraging theory on the assumption that foraging is operant behavior and operant behavior is foraging. This experiment tested the assumption that leverpressing is functionally equivalent to search effort. Four rats were exposed to two situations: a naturalistic foraging situation (a “patch”) and a standard operant chamber. Each condition represented a different prey density on the patch and a corresponding change in the probability of reinforcement in the chamber. The average number of presses per pellet was linearly related to the density of pellets on the patch. This result indicates that leverpresses were functionally equivalent to search effort. 相似文献
16.
In two experiments, we examined how the introduction of vertical or horizontal irregularities in the perfectly regular shape of a radial maze affected rats’ performances. The introduction of various tilts in each arm of an eight-arm radial maze had a slightly positive effect on accuracy. However, when intra- and extraraaze cues were dissociated by rotating the maze before maze completion, the rata relied preferentially on extramaze cues associated with the horizontal direction of the arms but not with the tilts. On the other hand, the rats showed poor performances when trained on a horizontally distorted maze (uneven angles between the arms instead of repeated 45° angles). The high number of errors was related to the neglect of particular arms, the disorganization of the patrolling sequences, and the tendency to chain the visit of five arms that formed a regular ahape. Other animals, trained in the same maze, displayed similar biases even after a pretraining phase with constrained choices. Results from the horizontally distorted maze confirm and extend data from the spontaneous alternation literature that choice behavior is influenced by rules of movement that favor large angle transitions and regular subdivisions of space. They also stress the relation between performance in the radial maze and spontaneous exploratory and foraging behaviors. 相似文献
17.
In two operant simulations of prey selection, the choice behavior of pigeons and the predictions of a model of the effect of session length on optimal prey selection were compared. All but one of the predictions were confirmed. In the first experiment, a higher proportion of “bad” items (comparatively long delays to food) was accepted in 10-min sessions in one operant chamber than in the first 10 min of 20-min sessions in a different chamber. The proportion of bad items accepted increased toward the end of the 20-min sessions. In the second experiment, the birds were exposed both to 20-min sessions in one distinctively marked operant chamber and to sessions of variable length, with a mean of 20 min, in another. A higher proportion of bad items was accepted in the variable-session chamber than in the fixed-session chamber at the beginning of the 20-min sessions. This difference decreased toward the end of the sessions but did not reverse as expected. In both experiments, an independent test analogous to the peak procedure was administered to establish whether the birds discriminated among the different session lengths. 相似文献
18.
In two experiments, the hypothesis that frustration mediates the production of schedule-induced polydipsia was tested. In Experiment I, a group in which reward was reduced from 6 to 2 pellets of food in an operant chamber was found to increase water intake compared to a group maintained at 2 pellets reward. In Experiment II, rats trained to approach food on a partial reinforcement schedule in a runway subsequently showed lower levels of water intake in the operant test for polydipsia than rats given continuous reinforcement during runway training. The results are interpreted as supporting a frustration hypothesis of schedule-induced polydipsia and are discussed within the context of persistence theory. 相似文献
19.
Are humans unique in their ability to interpret exogenous events as causes? We addressed this question by observing the behavior of rats for indications of causal learning. Within an operant motor–sensory preconditioning paradigm, associative surgical techniques revealed that rats attempted to control an outcome (i.e., a potential effect) by manipulating a potential exogenous cause (i.e., an intervention). Rats were able to generate an innocuous auditory stimulus. This stimulus was then paired with an aversive stimulus. The animals subsequently avoided potential generation of the predictive cue, but not if the aversive stimulus was subsequently devalued or the predictive cue was extinguished (Exp. 1). In Experiment 2, we demonstrated that the aversive stimulus we used was in fact aversive, that it was subject to devaluation, that the cue–aversive stimulus pairings did make the cue a conditioned stimulus, and that the cue was subject to extinction. In Experiments 3 and 4, we established that the decrease in leverpressing observed in Experiment 1 was goal-directed instrumental behavior rather than purely a product of Pavlovian conditioning. To the extent that interventions suggest causal reasoning, it appears that causal reasoning can be based on associations between contiguous exogenous events. Thus, contiguity appears capable of establishing causal relationships between exogenous events. Our results challenge the widely held view that causal learning is uniquely human, and suggest that causal learning is explicable in an associative framework. 相似文献
20.
Suppression of operant responding during a conditioned stimulus (CS) was studied in two procedures. In both procedures, operant leverpressing was maintained by a variable-interval 1-min food-delivery schedule, and insertion of a second lever served as the CS. In the first procedure, autoshaping, food followed each CS presentation irrespective of a subject’s behavior during the CS. In the second procedure, omission training, contact with the CS canceled the delivery of food scheduled for the end of that CS. In the first experiment, subjects were exposed to omission training followed by autoshaping; these procedures were reversed in the second experiment. In each experiment, the omission contingency resulted in fewer CS contacts and less suppression of operant responding during the CS than did autoshaping. These differences were more notable in subjects receiving the sequence autoshaping→omission training (Experiment 2). Direct observations in Experiment 2 revealed that, for subjects that were contacting the CS frequently when the omission contingency was introduced, reductions in signal contacts were accompanied by redistributions of behavior. The form of these redistributions depended upon behavior allocation at the time the omission contingency was imposed. 相似文献