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1.
It is said that “absence makes the heart grow fonder.” But, when and why does an absent event become salient to the heart or to the brain? An absent event may become salient when its nonoccurrence is surprising. Van Hamme and Wasserman (1994) found that a nonpresented but expected stimulus can actually change its associative status—and in the opposite direction from a presented stimulus. Associative models like that of Rescorla and Wagner (1972) focus only on presented cues; so, they cannot explain this result. However, absent cues can be permitted to change their value by assigning different learning parameters to present and absent cues. Van Hamme and Wasserman revised the Rescorla-Wagner model so that the α parameter is positive for present cues, but negative for absent cues; now, changes in the associative strength of absent cues move in the opposite direction as presented ones. This revised Rescorla-Wagner model can thus explain such otherwise vexing empirical findings as backward blocking, recovery from overshadowing, and backward conditioned inhibition. Moreover, the revised model predicts new effects. For example, explicit information about the absence of nonpresented cues should increase their salience (that is, their negative α value should be larger), leading to stronger associative changes than when no explicit mention is made of cue absence. Support for this prediction is detailed in a new causal judgment experiment in which participants rated the effectiveness of different foods’ triggering a patient’s allergic reaction. Overall, these and other findings encourage us to view human causal learning from an associative perspective. 相似文献
2.
Edward S. Redhead Derek A. Hamilton Matthew O. Parker Wai Chan Craig Allison 《Learning & behavior》2013,41(2):179-191
In three experiments, we examined whether overshadowing of geometric cues by a discrete landmark (beacon) is due to the relative saliences of the cues. Using a virtual water maze task, human participants were required to locate a platform marked by a beacon in a distinctively shaped pool. In Experiment 1, the beacon overshadowed geometric cues in a trapezium, but not in an isosceles triangle. The longer escape latencies during acquisition in the trapezium control group with no beacon suggest that the geometric cues in the trapezium were less salient than those in the triangle. In Experiment 2, we evaluated whether generalization decrement, caused by the removal of the beacon at test, could account for overshadowing. An additional beacon was placed in an alternative corner. For the control groups, the beacons were identical; for the overshadow groups, they were visually unique. Overshadowing was again found in the trapezium. In Experiment 3, we tested whether the absence of overshadowing in the triangle was due to the geometric cues being more salient than the beacon. Following training, the beacon was relocated to a different corner. Participants approached the beacon rather than the trained platform corner, suggesting that the beacon was more salient. These results suggest that associative processes do not fully explain cue competition in the spatial domain. 相似文献
3.
Philippe Oberling Adam S. Bristol Helena Matute Ralph R. Miller 《Learning & behavior》2000,28(2):172-186
Miller and Matute (1996) showed that blocking is attenuated when the blocked conditioned stimulus (CS) is “biologically significant” (i.e., when the CS has the potential to elicit vigorous responding of any kind). To the extent that blocking is representative of cue competition, this finding suggests that biological significance protects CSs against cue competition effects in general. In the present experiments, we tested this possibility by examining the influence of biological significance of CSs on other examples of cue competition, namely, overshadowing, the relative stimulus validity effect, and the degraded contingency effect in rats. In Experiment 1, we found that intense auditory stimuli induced transient unconditioned lick suppression, thereby indicating that intense sounds were of high inherent biological significance. In Experiment 2A, we found that cues with high inherent biological significance were protected from overshadowing. In Experiment 2B, this finding was extended to cues with high acquired biological significance, which was obtained through prior pairings with a reinforcer of the valence opposite to that used in the overshadowing treatment. In Experiments 3 and 4, we found that cues with high inherent biological significance attenuated the relative validity effect and the degraded contingency effect, respectively. These results lend support to the view that biological significance (inherent and acquired) protects stimuli from cue competition effects, a finding that is problematic for many contemporary theories of learning. 相似文献
4.
If freezing underlies barpress conditioned suppression, then it seems odd that auditory cues paired with shock evoke more freezing than do visual cues, yet evoke similar suppression. Bevins and Ayres (1992) found that auditory and visual cues also evoked similar withdrawal from the bar and dipper areas and suggested that such withdrawal could explain the similar suppression. Seeking to understand that withdrawal, we found evidence in the present study that it was due either to adventitious punishment or to place-aversion learning. The cue for shock seemed to set the occasion for such learning. For example, we found that, as training progressed, rats’ tendency to leave the bar area during the cue first increased, then decreased, then increased again, reflecting, presumably, shock occurrence first inside, then outside, then inside the bar area again. Despite these changes in the rats’ location, barpress suppression remained stable, implying that leaving the bar area, though sufficient for barpress suppression, is unnecessary. 相似文献
5.
In the blocking phase of three experiments, rats had to find a submerged platform beneath a spherical landmark in one corner
of a triangular pool. Prior to this treatment, they were required to find the platform relative to either a sphere above it
(blocking groups) or a rod attached to it (control groups). The position of the platform changed from trial to trial for the
initial training. The sphere did not restrict learning about the geometric cues provided by the triangular arena in the blocking
phase when 12 sessions of initial training took place in either the triangular (Experiment 1) or a circular (Experiment 3)
pool. Blocking was observed, however, after 24 sessions of initial training in either the triangular (Experiment 2) or the
circular (Experiment 3) pool. Thus, blocking of geometric cues by a landmark is possible after extended initial training with
the blocking cue. 相似文献
6.
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
7.
The experiment provides a direct comparison of the ability of subjects (rats) to associate gustatory and exteroceptive stimuli with illness. Previous experiments which have made similar comparisons between gustatory and exteroceptive cues have suffered from certain methodological problems involving stimulus control and compounding. The present experiment utilized a between-subjects design wherein half of the subjects had an auditory cue associated with poisoning and half had a taste cue. In both cases, the other cue was present, but was not predictive of poisoning, The auditory cue, like the taste cue, occurred only during drinking. This comparison was made in both an immediate and a delayed poisoning situation. The experiment found that while subjects were able to quickly associate a taste cue with illness, they were unable to form a similar association between poisoning and the exteroceptive stimulus. Results also showed that subjects will fail to acquire a taste aversion to a novel and salient gustatory cue when that cue is followed by illness only 50% of the time. This latter effect was more pronounced in the delayed poisoning situation. 相似文献
8.
Peter C. Holland Judith S. A. Asem Connor P. Galvin Caitlin Hepps Keeney Melanie Hsu Alexandra Miller Vivian Zhou 《Learning & behavior》2014,42(1):1-21
Rats will approach and contact a lever whose insertion into the chamber signals response-independent food delivery. This “autoshaping” or “sign-tracking” phenomenon has recently attracted considerable attention as a platform for studying individual differences in impulsivity, drug sensitization, and other traits associated with vulnerability to drug addiction. Here, we examined two basic stimulus selection phenomena—blocking and overshadowing—in the autoshaped lever pressing of rats. Blocking and overshadowing were decidedly asymmetrical. Previously reinforced lever-extension conditioned stimuli (CSs) completely blocked conditioning to auditory cues (Exps. 1 and 2), and previously nonreinforced lever-extension CSs overshadowed conditioning to auditory cues. By contrast, conditioning to lever-extension CSs was not blocked by either auditory (Exp. 3) or lever-insertion (Exp. 4) cues, and was not overshadowed by auditory cues. Conditioning to a lever-insertion cue was somewhat overshadowed by the presence of another lever, especially in terms of food cup behavior displayed after lever withdrawal. We discuss several frameworks in which the apparent immunity of autoshaped lever pressing to blocking might be understood. Given evidence that different brain systems are engaged when different kinds of cues are paired with food delivery, it is worth considering the possibility that interactions among them in learning and performance may follow different rules. In particular, it is intriguing to speculate that the roles of simple cue–reinforcer contiguity, as well as of individual and aggregate reinforcer prediction errors, may differ across stimulus classes. 相似文献
9.
In four experiments using rat subjects, we investigated the effects of presenting a novel flavor cue at the time of pairing an environmental context with illness. In each experiment, the subjects were allowed to spend time in a distinctive cage before receiving an injection of LiCl. For some, plain water was made available on these conditioning trials; for others, a novel taste (HCl) was presented. We measured the strength of the context aversion by assessing the ability of the contextual cues to block the acquisition of an aversion to sucrose in a further phase of training. We found that initial training with HCl present made the context less effective as a blocking cue and concluded that the HCl had overshadowed learning about the context. We suggest that this blocking procedure provides a more accurate assessment of contextual aversion than does the consumption test that has more usually been used and that taste-context overshadowing may be a more robust phenomenon than has thus far been thought. 相似文献
10.
In four trace-conditioning experiments with rats, the influence on the blocking of differences between the blocking cue-unconditioned
stimulus (US) and the blocked cue-US trace intervals was explored. Experiment 1 demonstrated blocking despite the blocked
cue’s having a shorter trace interval than the blocking cue in both elemental (Phase 1) and compound (Phase 2) training. In
Experiment 2, blocking was attenuated when the blocked cue had a longer trace interval than did the blocking cue in both elemental
and compound training. In Experiments 3 and 4, the trace intervals of the two cues during compound training were matched (i.e.,
unlike in Experiments 1 and 2, neither had temporal priority). Blocking was attenuated when the blocking cue trace interval
in the elemental phase was shorter (Experiment 3) or longer (Experiment 4) than the compound cue trace during compound training.
The findings indicate that subjects encode interstimulus intervals, and they further suggest that cue competition is greatest
when the competing cues have the same temporal information as the US. 相似文献
11.
Dominic J. Zerbolio 《Learning & behavior》1981,9(3):346-356
Goldfish, trained in a shuttlebox with cues and shock controlled by a linear presentation procedure, learned to control prevailing cue states and shock, and thus to discriminatively avoid shock presentation. The linear presentation procedure, adapted for the shuttlebox from the sequence of cue presentation occurring in the Y-maze, utilized three cues on each trial, a trial-start (TS) cue, a shock-paired (S?) cue, and an unpaired (S+) cue. At trial onset (TS cue), the goldfish had 10 sec to respond. The first response produced, via response-contingent programming, either the shock-paired (S?) or unpaired (S+) cue, and subsequent responses produced alternation of S+ and S?. The shock was omitted only if the S+ cue state prevailed 10 sec after trial onset. AU other cue states (TS and S?) were paired with shock. Goldfish learned to respond and control the prevailing cue state so that the S+ cue prevailed at 10 sec posttrial onset for a variety of different color-cue combinations and also learned to reverse their originally learned cue preference when the color cues were reversed. The linear presentation procedure represents an alternative discrimination learning procedure that appears to be free of the interpretational problems encountered in training goldfish in the shuttlebox apparatus with other one- and two-stimulus procedures. 相似文献
12.
In three human causal learning experiments, we examined attentional modulation in the blocking task, in which participants
typically learn little about a novel cue B when it is paired with a previously trained, predictive cue A. Evidence indicates
that this blocking training led to a decrement in attention to the blocked cue B. The present experiments addressed whether
this decrease in attention to the blocked cue could be better explained as being due to lateral inhibition from the pretrained
cue A to the blocked cue B, or as a cue-specific property that is not conditional on the presence or absence of other stimuli.
Strong effects of learned predictiveness were observed on participants’ causal judgments (Experiment 1) and choice behavior
(Experiments 2 and 3). However, no evidence for lateral inhibitory processes emerged in any of the experiments, despite explicit
attempts to maximize experimental sensitivity to this effect. The results are discussed in the context of formal models of
the operation of attentional processes in human and animal learning. 相似文献
13.
Alliston K. Reid Grace DeMarco Kelsey Smith Theodore Fort Erica Cousins 《Learning & behavior》2013,41(4):455-463
How does the effectiveness of guiding cues influence the development of motor skill autonomy? We utilized two sets of guiding cues (lights vs. reversed-lights conditions) that differed in their effectiveness to control a left–right leverpress sequence in rats. We separately measured the development of stimulus control by panel lights on guiding-cues trials and the development of stimulus control by practice cues on no-cue probe trials within the same sessions. Accuracy in the presence of the guiding cues was acquired faster in the lights condition than in the reversed-lights condition, but subjects in the reversed-lights condition were more able to complete the skill autonomously than those in the lights condition. Throughout acquisition, control by guiding cues and practice cues developed at the same rate in the reversed-lights condition, but control by practice cues (autonomy) developed at a slower rate than did control by guiding cues in the lights condition. At the end of training, subjects that had been exposed to the reversed-lights condition displayed higher levels of autonomy than did those exposed to the lights condition. The less effective guiding cue (reversed-lights) produced greater levels of autonomy than did the more effective cue (lights), even though control by this guiding cue developed more slowly. Thus, guiding your child by the hand too much may reduce his or her ability to complete the task independently. We discuss the similarity to prompt dependence in children with learning disabilities and transfer of stimulus control. 相似文献
14.
Associative learning theories assume that cue interaction and, specifically, retrospective revaluation occur only when the target cue is previously trained in compound with the to-be-revalued cue. However, there are recent demonstrations of retrospective revaluation in the absence of compound training (e.g., Matute &; Pineño, 1998a, 1998b). Nevertheless, it seems reasonable to assume that cue interaction should be stronger when the cues are trained together than when they are trained apart. In two experiments with humans, we directly compared compound and elemental training of cues. The results showed that retrospective revaluation in the elemental condition can be as strong as and, sometimes, stronger than that in the compound condition. This suggests that within-compound associations are not necessary for retrospective revaluation to occur and that these effects can possibly be best understood in the framework of general interference theory. 相似文献
15.
The blocking phenomenon was investigated in the sexual response system of male Japanese quail. Access to a live female quail served as the unconditioned stimulus (US). The same audiovisual cue served as the pretrained stimulus in all of the experiments. Following asymptotic conditioning of the audiovisual cue, a second conditioned stimulus (CS2) was added. In Experiment 1, CS2 was a rectangular wood block that had little or no resemblance to a female quail and could not support copulatory behavior. In Experiment 2, CS2 was a terrycloth object that had no quail parts but could support copulatory behavior, and, in Experiment 3, CS2 was a terrycloth object that had a taxidermically prepared head of a female quail added. The terrycloth-only object supported more rapid conditioning than did the wood block, but the blocking effect was obtained with both kinds of stimuli. Approach responding to the terrycloth + head object required pairing it with copulatory opportunity, and the terrycloth + head object supported at least as rapid conditioning as did the terrycloth-only object. However, responding to the terrycloth + head object was not blocked by the pretrained audiovisual cue. These results indicate that the blocking effect occurs in sexual conditioning even with stimulus objects that can support copulation. However, the addition of species-typical head cues to an object makes that object such a powerful stimulus that conditioned approach responding to it cannot be blocked by a previously conditioned arbitrary audiovisual cue. 相似文献
16.
Rats collected nuts from a container in a large arena in four experiments testing how learning about a beacon or cue at a
goal interacts with learning about other spatial cues (place learning). Place learning was quick, with little evidence of
competition from the beacon (Experiments 1 and 2). Rats trained to approach a beacon regardless of its location were subsequently
impaired when the well-learned beacon was removed and other spatial cues identified the location of the goal (Experiment 3).
The competition between beacon and place cues reflected learned irrelevance for place cues (Experiment 4). The findings differ
from those of some studies of associative interactions between cue and place learning in other paradigms. 相似文献
17.
We trained 7 pigeons to discriminate visual displays of 16same items from displays of 16different items. The specific stimulus features of the items and the relations among the items could serve as discriminative stimuli.
Unlike in most studies of same-different discrimination behavior, we gave a small number of probe tests during each session
of acquisition to measure the time-course of control by the learning of specific stimulus features and relational cues. Both
the specific stimulus features and relational cues exerted reliable stimulus control, with the specific stimulus features
exerting more control during the final three fourths of same-different learning. These findings replicate research suggesting
that pigeons encode both the specific stimulus features and relational cues, and for the first time document the time-course
of control by each kind of cue. 相似文献
18.
《The Journal of educational research》2012,105(2):105-109
AbstractAnthropomorphism as a cue in word learning was investigated in relation to illustration and no picture cue conditions in trials to criterion and word memory tasks with kindergarten children. The study and test trials format of the study replicated similar studies hut employed unique anthropomorphic cues with similar and dissimilar words. Analysis of variance w as used to investigate differences among training conditions (anthropomorphic, illustration, and no picture) and word types (similar and dissimilar). Significant differences were found between similar and dissimilar word types with the dissimilar words being learned more easily. Significant differences were found between training conditions w ith the anthropomorphic cues leading to enhanced learning and retention for both similar and dissimilar words. 相似文献
19.
Dickinson and Burke (1996) proposed a modified version of Wagner’s (1981) SOP associative theory to explain retrospective
revaluation of human causal judgments. In this modified SOP (MSOP), excitatory learning occurs when cue and outcome representations
are either both directly activated or both associatively activated. By contrast, inhibitory learning occurs when one representation
is directly activated while the other is associatively activated. Finite node simulations of MSOP yielded simple acquisition,
overshadowing, blocking, and inhibitory learning under forward contingencies. Importantly, retrospective revaluation was predicted
in the form of unovershadowing and backward inhibitory learning. However, MSOP did not yield backward blocking. These predictions
are evaluated against the relevant empirical evidence and contrasted with the predictions of other associative theories that
have been applied to retrospective revaluation of human causal and predictive learning. 相似文献
20.
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