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1.
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
2.
Rats found food in a rectangular enclosure in three experiments testing how learning about a distinctive feature near a goal
interacts with learning based on the geometry of an enclosure. Rats trained to follow a feature in square and triangular enclosures
and to use geometry in the rectangle followed the feature when it was in the rectangle (Experiment 1). Rats trained with the
feature in a geometrically consistent corner of the rectangle learned about both geometry and the feature (Experiment 2).
Training with the feature in the square did not block learning of geometry when both predicted the location of food in the
rectangle (Experiment 3). The “geometric module” (Cheng, 1986) may have a special status in spatial learning. 相似文献
3.
4.
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
5.
Two experiments were conducted to examine the effects of redundant and relevant visual cues on spatial pattern learning. Rats searched for hidden food items on the tops of poles that formed a square (Experiment 1) or a checkerboard (Experiment 2) pattern. The experimental groups were trained with visual cues that specified the locations of the baited poles. All groups were tested without visual cues so that any overshadowing or facilitation of spatial pattern learning by visual cues could be detected. Spatial choices were controlled by the spatial pattern and by the visual cues in both experiments. However, there was no evidence of overshadowing or facilitation of spatial pattern learning by visual cues in either experiment. The results are consistent with the idea that the representation of the spatial pattern that guides choices is not controlled by the same learning processes as those that produce associations between visual cues and food locations. 相似文献
6.
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
7.
Experiments were designed in which some properties of spatial representations in rats could be examined. Adult subjects were trained to escape through a hole at a fixed position in a large circular arena (see Schenk, 1989). The experiments were conducted in the dark, with a limited number of controlled visual light cues, in order to assess the minimal cue requirement for place learning. Three light cues identical in shape, height, and distance from the table were used. Depending on the condition, they were either permanently on or alternatively on or off, contingent on the position of the rat in the field. Two questions were asked: (1) How many identical visual cues were necessary for spatial discrimination in the dark, and (2) could rats integrate the relative positions of separate cues, under conditions in which the rat was never allowed to perceive all three cues simultaneously. The results suggest that rats are able to achieve a place discrimination task even if the three cues necessary for efficient orientation can never be seen simultaneously. A dissociation between the discrimination of the spatial position of the goal and the capacity to reach it by a direct path suggests that, with a reduced number of cues, prolonged locomotion might be required for accurate orientation in the environment. 相似文献
8.
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
9.
Rats were trained in a triangular-shaped pool to find a hidden platform that maintained a constant relationship with two sources
of information, an individual landmark and one part of the pool with a distinctive shape. In Experiment 1, shape learning overshadowed landmark learning but landmark learning did not overshadow shape learning in males, while landmark
learning overshadowed shape learning but shape learning did not overshadow landmark learning in females. In Experiment 2,
rats were pretrained either with the single landmark relevant or with the shape relevant, in the absence of the alternative
cue. Final test trials, without the platform, revealed reciprocal blocking only in females; in males, shape learning blocked
landmark learning, but not viceversa (Experiment 2a). In Experiment 2b, male rats received a longer pretraining with the single landmark relevant, and now landmark learning blocked shape learning.
The results thus confirm the claim that males and females partially use different types of spatial information when solving
spatial tasks. These results also agree with the suggestion that shape learning interacts with landmark learning in much the
same way as does learning about any pair of stimuli in a Pavlovian conditioning experiment. 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.
A series of experiments was conducted to examine the phenomenon of potentiation. Experiment 1 demonstrated potentiation of odor aversions by taste when morphine served as the unconditioned stimulus (US). Experiment 2 provided evidence that the observed potentiation was due to a within-event association between odor and taste stimuli, rather than reflecting an enhanced odor-morphine association. In Experiment 3, morphine supported place conditioning to contextual cues and aversive conditioning to a taste cue, but potentiation of place conditioning by a taste cue was not obtained. Apparently the absence of potentiation was due to the dual nature of the morphine US, as potentiation of a contextual aversion by taste was obtained in Experiment 4 when a strictly aversive US (lithium) was used. These data suggest that potentiation depends on (1) an initially weak association between the to-be-potentiated conditioned stimulus (CS) element and the US, and (2) the elicitation of qualitatively similar responses by the individual elements of the CS compound. Collectively, these results support an explanation of potentiation based on within-event learning. 相似文献
12.
Ariane S. Etienne Sylvie Joris Lambert Benoit Reverdin Evelyne Teroni 《Learning & behavior》1993,21(3):266-280
In Experiment 1, hamsters started from their permanent home at the periphery of a circular arena and headed to a food source at the center. They then returned, fully laden with food, along a direct path to their home. On control trials, in which no manipulation takes place, visual cues outside the arena and dead reckoning (i.e., updated internal references generated during the outward journey to the food source) controlled the return journey. On experimental trials, the arena, with the hamster in its nest, was rotated by 90°, putting dead reckoning at variance with the distal visual environment. The animals were rewarded for going with dead reckoning. At first, they favored the distal cues, but later most of the subjects switched to using dead reckoning. Thus, hamsters are flexible enough to recalibrate the relative weight that they normally attribute to different sets of spatial cues. In Experiment 2, the reliance on dead-reckoning was greatly enhanced when a cue card at the nest entrance was rotated along with the arena, pitting one proximal cue plus dead reckoning against distal cues. Hence, dead reckoning and external cues seem to reinforce each other through their mutual correlation. 相似文献
13.
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
14.
Rats obtained food from the tops of vertical poles in a 5 × 5 matrix of locations. On each trial, the baited locations formed
one of the two possible exemplars of a checkerboard spatial pattern. During training, locations that had been visited earlier
in the trial were indicated by a visual cue. Following training, performance with and without the visual cues was compared.
Spatial choices were controlled by the checkerboard spatial pattern. The visual cues enhanced the ability of rats to avoid
revisits of locations. However, the visual cues did not enhance control by the spatial pattern, as would be expected if the
same spatial memories were involved in avoidance of revisits and coding the location of baited locations. 相似文献
15.
Two fear-conditioning experiments with rats assessed whether retrospective revaluation, which has been observed in cue competition (i.e., when compounded cues are followed with an outcome), can also be observed in retroactive cue interference (i.e., when different cues are reinforced in separate phases with the same outcome). Experiment 1 found that after inducing retroactive cue interference (i.e., X-outcome followed by A-outcome), nonreinforced presentations of the interfering cue (A) decreases interference with responding to the target cue (X), just as has been observed in retrospective revaluation experiments in cue competition. Using the opposite manipulation (i.e., adding reinforced presentations of A), Experiment 2 demonstrated that after inducing retroactive cue interference, additional reinforced presentations of the interfering cue (A) increases interference with responding to the target cue (X); alternatively stated, the amount of interference increases with the amount of training with the interfering cue. Thus, both types of retrospective revaluation occur in retroactive cue competition. The results are discussed in terms of the possibility that similar associative mechanisms underlie cue competition and cue interference. 相似文献
16.
When people judge the contingency between a target cue and an outcome, they also take into account the contingency between
the outcome and other cues with which the target cue co-occurred. Several authors have argued that such cue competition effects
are due to higher order reasoning processes. We review the evidence that supports this hypothesis and discuss whether higher
order reasoning might also play a role in other learning phenomena. 相似文献
17.
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
18.
Two experiments were run in order to investigate the influence of external contextual cues on the interaction between two conflicting memories. Rats were trained, in the same apparatus, on a passive-avoidance task and, 10 min later, on an active-avoidance task, then submitted to a 24-h delayed test (without reinforcement). When contextual cues remained unchanged throughout these three phases, the animals exhibited proactive interference, as shown by longer response latencies than those of control animals that had learned only the active-avoidance task (Experiment 1). When training contexts were made slightly different from one task to the other (by the presence of a continuous tone during either the first or the second task), the animals behaved at subsequent testing in accordance with the response contingencies present in the context exactly similar to the test context; this control of behavior by testing context was demonstrated both when the tone was absent (Experiments 1 and 2) and present (Experiment 2) at testing. A cuing procedure—a 90-sec exposure to the tone in the experimental room 5 min prior to testing—led the animals to behave in accordance with the response previously acquired in the presence of the tone (Experiments 1 and 2), exactly in the same way as animals tested in the presence of the tone (Experiment 2). The same cuing treatment was ineffective when administered 1 h before testing (Experiment 2). These results are interpreted in terms of a dual function of contextual cues at the time of retrieval: the general contextual information present during testing or during pretest cuing is assumed to induce concurrent reactivation of both memories. Consequently, the experimentally manipulated contextual cue (the tone) would have a discriminative function, leading the animals to choose between the two equally available representations. 相似文献
19.
Two experiments are presented in which the influence of socially cued videos on the knowledge acquisition of video and subsequent non-video content in a computer-based learning environment was assessed. Participants explored a computer-based learning environment including four subsections – two subsections preceded by a video containing a high level of social cues and two subsections preceded by a video containing a low level of social cues. Knowledge acquisition of video and subsequent non-video content was assessed immediately (Experiment 1) and one week later (Experiment 2). The results show a social cue effect on the knowledge acquisition of video contents immediately after the exploration of the computer-based learning environment, an effect probably stemming from reduced cognitive effort. When tested one week later, there was only an effect on knowledge acquisition of the subsequent non-video contents of the computer-based learning environment, indicating procedural priming of deeper processing strategies. 相似文献
20.
Previous research has demonstrated that preschoolers can use situation-specific (e.g., visual access) and person-specific (e.g., prior accuracy) cues to infer what others know. The present studies investigated whether 4- and 5-year-olds appreciate the differential informativeness of these types of cues. In Experiment 1 (N = 50), children used others' prior labeling accuracy as a cue when learning labels for, but not the visual identity of, hidden objects. In Experiment 2 (N = 64), with both cues present, children attended more to visual access than prior accuracy when learning the visual identity of, but not labels for, hidden objects. These findings demonstrate that children appreciate the difference between situation- and person-specific cues and flexibly evaluate these cues depending on what information they are seeking. 相似文献