Effects of forced-choice runway variations on rats’ T-maze serial pattern learning     

Szelest I  Cohen J 《Learning & behavior》2006,34(2):202-214

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   

Serial learning,interitem associations,phrasing cues,interference, overshadowing,chunking, memory,and extinction     

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   

Some further observations on serial enumeration and categorical flexibility     

Richard A. Burns  Walter U. Gordon 《Learning & behavior》1988,16(4):425-428

Rats were runway-trained in a variety of serial discriminations that involved three different reward outcomes: Noyes pellets (R), a Kellogg’s Corn Pop (R’), and 30 sec of confinement in an unbaited goal area (N). Each of three groups experienced a series that consisted of a single non-rewarded trip down the runway, irregularly mixed with a longer series that for one group (n = 3) consisted of three trips rewarded with the pellets, followed by a terminal nonrewarded trip (RRRN/N). A second group (n = 6) had the single N series mixed with a series that included an initial trip rewarded with a Pop, and three subsequent trips rewarded with pellets, pellets, and nothing, respectively (R’RRN/N). The remaining group was trained with an RRN/N series pair. The interval between trips within a series was about 20 sec, and the interval between series was about 10 min. All rats developed strong, accurate anticipation of the terminal nonreward event of the longer series. In a 4-day transfer shift phase, a matched one-half of the rats originally trained R’RRN/N were shifted to a new series pair, RRRN/NRRRN, as were all the animals trained RRN/N. The remaining one-half of the matched rats were shifted to RRN/NRRN, as were the animals originally trained on the RRRN/N series pair. The transfer to the new series was plainly more powerful in animals initially trained with the R’RRN series than it was in either of the control groups. This shift result is taken to mean that rats classified the differing motivational events of the R’RRN series into at least three numerical categories: (1) one R’, (2) two Rs, and (3) three rewards.  相似文献   

Effect of prior nonreward on subsequent incentive growth during brief acquisition     

Charles I. Brooks 《Learning & behavior》1980,8(1):143-151

Four experiments compared runway extinction or hurdle-jumping from nonreward performance following brief (10 trials) continuous or partial reinforcement acquisition. Some of the partial groups received all nonrewarded trials prior to any rewards. The major findings were that (l) rats receiving all nonrewarded experiences prior to rewarded ones were more persistent during extinction than continuously rewarded subjects; (2) rats receiving nonrewarded placements prior to rewarded ones in one compartment of a two-compartment box, failed to learn a hurdle-jumping response to escape nonreward, whereas rats not receiving the initial nonrewards did learn the escape response; (3) increasing the number of rewarded placements following initial nonrewarded ones offset the effect noted in (2). The results, which are discussed in the context of a frustration analysis of the small-trials partial reinforcement effect, suggest that incentive growth over rewarded trials is retarded when the rewards have been preceded by nonrewards. The similarity of these results to those investigating the phenomenon of latent inhibition is apparent, and possible mechanisms responsible for the present results are suggested in current theoretical accounts of latent inhibition.  相似文献   

Effects of runway shift and stay rules on rats’ serial pattern learning in the T-maze     

Cohen J  Westlake K  Szelest I 《Learning & behavior》2004,32(4):500-511

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   

Maze patrolling by rats with and without food reward     

R.E Fitzgerald  R. Isler  E. Rosenberg  R. Oettinger  K. Bättig 《Learning & behavior》1985,13(4):451-462

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   

Rats exhibit asymmetrical retention functions for hedonic and nonhedonic samples in many-to-one symbolic delayed matching to sample     

Angelo Santi  Sabrina Simmons  Shannon Mischler  Claire Hoover 《Learning & behavior》2013,41(2):168-178

Rats were initially trained in a symbolic delayed matching-to-sample task either to discriminate hedonic samples that consisted of food or no food or to discriminate tone samples that differed in frequency and location. The retention functions for both the hedonic and tone samples were asymmetric, with forgetting of the food sample or the high-frequency tone occurring more rapidly than forgetting of the no-food sample or the low-frequency tone. Next, many-to-one (MTO) training was given in which tone samples were added for the rats initially trained with hedonic samples, and hedonic samples were added for the rats initially trained with tone samples. For both groups, a food sample and a tone sample (tone-F) were associated with responding to one lever (e.g., stationary), and a no-food sample and a different tone sample (tone-NF) were associated with responding to the alternative lever (e.g., moving). During retention testing, we found equivalent forgetting for the food and no-food samples, but forgetting of the tone-F sample occurred more rapidly than forgetting of the tone-NF sample. This is the first MTO study to suggest that rats, like pigeons, may use hedonic samples as the basis for the common coding of nonhedonic samples in MTO delayed matching.  相似文献   

An analysis of “signaled double-alternation patterning” in the rat     

W. B. Pavlik  Alexis C. Collier 《Learning & behavior》1975,3(1):73-75

Rats given training with double alternation of rewards and nonrewards in which the first reward or nonreward of each pair occurred in a black runway and the second in a white runway developed fast running on rewarded trials in both runways and slow running on nonrewarded trials in both runways—signaled double alternation patterning. A subsequent shift in the reinforcement schedule produced a period of reversed patterning—slow on rewarded trials and fast on nonrewarded trials. The results are consistent with a compound stimulus discrimination interpretation of signaled double-alternation patterning rather than with a selective memory-retrieval explanation.  相似文献   

Ordinal position in the serial learning of rats     

Richard A. Burns  John A. Dunkman  Stacy L. Detloff 《Learning & behavior》1999,27(3):272-279

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   

Successive acquisition and extinction in a runway with the domestic Muscovy duck (Cairina moschata)     

Robert S. Slavin  Robert B. Tallarico 《Learning & behavior》1975,3(2):90-92

Twenty domestic Muscovy ducks were trained to traverse a runway for food reward. Subjects were then randomly assigned to treatments. In one treatment, subjects received six nonrewarded trials followed by six rewarded trials every day for 12 days; and, in the other treatment, subjects received six rewarded trials followed by six nonrewarded trials every day for 12 days. These successive acquisition and extinction (SAE) treatments were selected because different extinction rates on the nonrewarded trials are expected on the bases of previous research performed with rats. Analyses of variance revealed the former treatment yielded significantly greater resistance to extinction than did the latter treatment. It was concluded that ducklings performed similarly to rats in the above SAE situation.  相似文献   

Difficult serial anticipation learning in rats: Rule-encoding vs. memory     

E. J. Capaldi  Timothy M. Nawrocki  Donna R. Verry 《Learning & behavior》1982,10(2):167-170

Rats, trained in a runway, were asked to anticipate, while running slowly, the last two events in repeating series of .045-g food pellets. The series were either weakly monotonic (14, 5, 5, 1, and then 0 pellets/run) or nonmonotonic (5-5-14-1-0). While the terminal 0-pellet event was better anticipated in the weakly monotonic series, the reverse was the case for the next-to-last 1-pellet event. These findings were expected from a memory-discrimination learning hypothesis of serial learning, which suggests that the memory of one event in a series can be used to signal the next event. However, the better anticipation of the 1-pellet event by the nonmonotonic group was inconsistent with the recently stated rule-encoding position of Hulse (1980). According to that view, difficult series of the sort employed in the present investigation are learned by encoding the rule structure of the series, with events in the series with the simple rule structure (the weakly monotonic series in this investigation) being better anticipated than events in the series with the complex rule structure.  相似文献   

Performance in differential instrumental conditioning as a function of the pattern of partial S+ reward     

James H. McHose  David R. Blackwell 《Learning & behavior》1975,3(1):63-66

A total of 46 rats, distributed across two experiments, received differential instrumental conditioning trials in a nonchoice brightness-discrimination apparatus. In each experiment, groups differed with respect to the pattern of rewarded and nonrewarded S+ trials. Response in S? was never reinforced. The results of both experiments indicated that the pattern of S+ reward events influences S? response levels in a fashion consistent with expectations derived from stimulus-specificity theory.  相似文献   

The role of reinforcement and nonreinforcement in an operant frustration effect     

Larry F. Hughes  Lawrence Dachowski 《Learning & behavior》1973,1(1):68-72

Male albino rats were run in a discrete-trial two-bar operant analog of the double alley. Completion of a FR 4 response chain on the first bar was rewarded 50% of the time for the 12 experimental Ss, but was never rewarded for the 12 control Ss. Both groups received consistent reward at the end of a FR 4 chain on the second bar. Eighty-four trials were given at a rate of four trials per day. A significantly faster rate of responding on the second bar was found following nonrewarded first-bar ratios than following rewarded first-bar ratios. This frustration effect was not attributable to response depression, since the nonrewarded performance of the experimental group exceeded that of the control group.  相似文献   

Stimulus control of anticipatory responding in instrumental learning as revealed in serial learning tasks     

E. J. Capaldi  Ronald M. Miller 《Learning & behavior》2001,29(2):165-175

Items in a fixed series A-B-C can be anticipated employing either item information (e.g., ItemA cues signal Item B) or position information (e.g., Position 2 cues signal Item B). Identical fixed series of rewarded and nonrewarded trials were employed in investigations reported by Capaldi and Miller (1988), Capaldi, Alptekin, Miller, and Birmingham (1997), and Burns, Dunkman, and Detloff (1999). These series were learned employing item cues according to Capaldi and colleagues and position cues according to Burns et al. (1999). Burns et al.’s (1999) conclusions were based on rats’ behavior when shifted to novel series, which could reveal position learning but not item learning. Employing the acquisition conditions of Burns and co-workers but shifts to series that could reveal item learning, evidence for item learning was obtained in two experiments. The most reasonable interpretation of the above set of findings is that rats employ a compound of both types of cues to signal items. To our knowledge, no set of prior findings so strongly suggests a similar conclusion.  相似文献   

Temporal cuing of runs in series of reward events reduces interevent anticipation     

Richard A. Burns  Larry P. Wiley  Terri L. Payne 《Learning & behavior》1986,14(2):190-196

In Experiment 1, a group of rats were runway trained on each of two reward series for 32 days. The two series consisted of three runs, the first two of which were, respectively, rewarded and nonrewarded; the third run was rewarded in one series but nonrewarded in the other. A 40-min interval separated the two series; the first and second runs within the series were separated by a 10-min interval, whereas the second and third runs were separated by a 30-sec interval. The reward (and nonreward) events and temporal cues of the two series are designated R-NR/R-NN. A second group was similarly trained, with the exception that the 10-min interval separated the second and third runs (RN-R/RN-N). Both groups developed appropriate differential running on the third run of the two series, and the RN-R/RN-N animals ran appropriately (slowly) on the second run of both series. Appropriate Run 2 performance appeared in one half of the R-NR/R-NN animals (depending upon order of series presentation); the remaining half ran faster on Run 2 of the R-NR series than on the same run of the R-NN series, an effect currently termed interevent anticipation. A cue shift phase in which all within-series intervals were 30 sec showed that the temporal intervals were controlling performance before the shift. Experiment 2 showed that interevent anticipation appears when all within-series intervals are either 10 min or 30 sec from the beginning of training, suggesting that the elimination of interevent anticipation in Experiment 1 was due to the differential cuing of runs by the temporal intervals rather than the particular interval duration. The overall findings suggest that the similarity of Run 2 and Run 3 performance termed interevent anticipation may be due to a failure to discriminate the ordinal position of runs within a series.  相似文献   

The development of self-reinforcing running in satiated rats     

Luci Paul  Frank Calabrese 《Learning & behavior》1973,1(4):268-272

Fast, “playful” running was obtained in rats never given reward for running in an alley. The maintenance of such running was not dependent on hunger, thirst, or an “exercise” drive produced by confinement in small home cages. However, hunger facilitated the development of “playful” nonrewarded running in rats which initially did not run when food-satiated. “Playful” running was not seen in hungry, rewarded rats or in hungry, nonrewarded rats fed immediately after their daily running sessions. Probably incentive, but not drive, prevents the occurrence of self-reinforcing running.  相似文献   

Role of proactive interference in infantile forgetting     

Gregory J. Smith  Norman E. Spear 《Learning & behavior》1981,9(3):371-380

Ontogenetic changes in the role of proactive interference in augmenting forgetting were tested with 444 rats as subjects. In Experiment 1, Phase 1 (the source of proactive interference) included events that were contingent or not contingent on responding in the context of either the Phase 2 training apparatus or a distinctly different apparatus. After learning a spatial discrimination for Phase 2, retention tests were given after intervals of 2 min, 1 day, 7 days, 30 days, or 65 days. The results indicated: (1) infantile amnesia, and (2) proactive interference for infant rats but not for adults, in spite of substantial simple forgetting among adults. Experiment 2 extended the test to a go/no-go avoidance task. The results of Experiment 2 gave some indication that infants were more susceptible than were adults to proactive interference over short intervals, but the generality of this relationship was sufficiently ambiguous as to suggest different mechanisms of interference for the discrimination and go/no-go tasks. These data indicate multiple mechanisms of infantile forgetting that may vary with certain characteristics of the task.  相似文献   

Forgetting functions     

K. Geoffrey White 《Learning & behavior》2001,29(3):193-207

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Effect of N-R transitions during partial reinforcement pretraining on subsequent resistance to discrimination     

Steven J. Haggbloom 《Learning & behavior》1982,10(1):61-64

Three groups of 12 rats received 25 pretraining trials to each future discriminandum employed in a subsequent differential brightness conditioning problem. Groups NR and RN received partial reinforcement (PRF) pretraining either with or without, respectively, transitions from nonrewarded to rewarded trials (N-R transitions). Group CRF received consistent reinforcement during pretraining. A fourth group (n=12), Group NP, received no pretraining. During discrimination learning, one-half of the rats in each group received all their daily S+ trials preceding their daily S? trials (+? sequence); the remainder of the rats received an intermixed sequence of trials to S+ and S? (+?+ sequence). Discrimination learning was faster under the +? sequence than under the +?+ condition, and discrimination learning was retarded in Group NR relative to the other three groups, which did not differ from one another, under both the +? and +?+ discrimination sequence conditions. The results are discussed with Reference to previous experiments demonstrating N-R transition effects on discrimination learning, a theoretical extension of sequential theory to discrimination learning, and the effects of nondifferential reinforcement prior to discrimination learning on learned irrelevance.  相似文献   

Effects of sucrose concentrations on single-alternation performance in rats     

J. J. Franchina  J. M. Billig 《Learning & behavior》1978,6(3):320-329

In Experiment 1, rats received single-alternation training with 32% or 4% sucrose reward (Phase 1) followed by a shift in reward from 32% to 4%, and vice versa (Phase 2). In Phase 1, high reward facilitated alternation performance over low reward. In Phase 2, performance on rewarded trials increased as reward increased but was unchanged as reward decreased. Performance on nonrewarded trials showed negligible effects of shifts in reward. In Experiment 2, rats received goalbox placements with 32% or 4% sucrose alternated with nonreward in Phase 1; and in Phase 2, they received alternation runway training with the same or the opposite reward from that of placements. Performance on rewarded trials was faster, the higher the reward in runway training; performance on nonrewarded trials was slower, the higher the reward in placements. In Experiment 3, Phase 1 provided placements with 64%, 32%, 16%, or 4% sucrose or dry mash alternated with nonreward; Phase 2 provided alternation runway training with dry mash reward. Alternation prerformance developed more rapidly, the higher the sucrose concentration in placements. Only 64% sucrose produced performance superior to that for dry-mash placements.  相似文献