Retroactive inhibition in rat spatial memory

Two experiments were carried out in which rats first were given four forced choices on an eight-arm radial maze, then were given interpolated maze experiences, and finally were given a free choice retention test on the first maze. In Experiment 1, interpolated experiences consisted of forced choices made on one, two, or three other mazes, each placed in a different room. Retroactive inhibition (RI) was not found with one and two interpolated mazes but was found with three interpolated mazes. In Experiments 2a and 2b, an attempt was made to produce RI within a single context by using two mazes placed side by side or on top of one another and by using interpolated forced choices that were different, random, or the same with respect to forced choices onMaze 1. These conditions failed to yield any evidence of RI. In Experiment 2c, forced choices were followed by interpolated direct placements on the same maze on different, random, or the same maze arms, and retention tests revealed RI under these conditions. It was concluded that rats encode memories of specific places visited in space and that RI will arise only if (1) memory is greatly overloaded with interpolated information or (2) an interpolated visit is made to exactly that position in space to which an animal must travel in order to achieve a correct choice on the retention test.     

Retrospective revaluation of associative retroactive cue interference

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.     

An elemental model of retrospective revaluation without within-compound associations

When retrospective revaluation phenomena (e.g., unovershadowing: AB+, then A?, then test B) were discovered, simple elemental models were at a disadvantage because they could not explain such phenomena. Extensions of these models and novel models appealed to within-compound associations to accommodate these new data. Here, we present an elemental, neural network model of conditioning that explains retrospective revaluation apart from within-compound associations. In the model, previously paired stimuli (say, A and B, after AB+) come to activate similar ensembles of neurons, so that revaluation of one stimulus (A?) has the opposite effect on the other stimulus (B) through changes (decreases) in the strength of the inhibitory connections between neurons activated by B. The ventral striatum is discussed as a possible home for the structure and function of the present model.     

Retroactive interference and rate of forgetting in delayed matching-to-sample performance

Previous evidence suggests that a disruptive stimulus presented during the delay interval of a delayed matching-to-sample trial increases the rate of forgetting by pigeons. However, disruptive events have generally been presented for a period of time proportional to the delay interval. Thus, the observed increase in forgetting may be the result of greater exposure to these events at longer delays than at shorter ones. This possibility was examined by comparing the effects of houselight illumination for the entire delay, half the delay, or a constant 1.5 sec of each delay on pigeons’ delayed matching-to-sample accuracy. Presenting the houselight for a period of time proportional to each delay (i.e., the entire delay or half the delay) impaired accuracy more at longer delays than at shorter delays. By contrast, when the houselight was illuminated for 1.5 sec, irrespective of delay length, there was a greater impairment in accuracy at shorter delays than at longer delays. Thus, the increased rate of forgetting previously reported in the literature may be the result of unequal application of a disrupting stimulus across delays.     

Expression of a taste aversion conditioned with an odor-taste compound: Overshadowing is relatively weak in weanlings and decreases over a retention interval in adults

Adult rats were injected with lithium chloride (LiCl) after consumption of a novel flavor (chocolate milk) that either was or was not presented together with a novel ambient odor (banana) as a compound conditioned stimulus (CS). In Experiment 1, the adults’ consumption of the flavor 24 h after conditioning was compared with that of weanling rats given the same conditioning treatment on Postnatal Day 21. The results confirmed previous indications that the reduction in aversion observed for adults conditioned with the compound CS (overshadowing) was weak or nonexistent in weanlings. After a longer retention interval (21 days), there was no evidence of overshadowing in adults despite maintained retention of the basic conditioned aversion. In Experiment 2 this decrease in overshadowing after a long retention interval was replicated with adult animals and extended to a different method of testing. The form of the effect was the same as in Experiment 1: The decrease in overshadowing occurred over the retention interval without loss in retention of the basic taste aversion; the decrease in overshadowing was a consequence of anincrease in the flavor aversion displayed by animals conditioned with the compound CS. The impaired flavor aversion (i.e., the overshadowing) observed shortly after conditioning apparently was due to factors associated with memory retrieval, rather than to reduced attentional or associative strength.     

Direct effects on instrumental performance of outcome revaluation by drive shifts

In three experiments the sensitivity of instrumental responding to revaluation of the instrumental outcome in the absence of experience with the revalued outcome was examined. Hungry rats were trained to make one response for food pellets and a different response for sucrose liquid. In Experiment 1, these responses were tested in extinction when the animals were either thirsty or hungry. A significant preference for the sucrose-trained response was observed in the test conducted under thirst but not in that conducted under hunger. In Experiments 2 and 3, the effect of experience with sucrose under thirst on the magnitude of this preference was explored. Following training of the instrumental responses in Experiment 2, half of the animals received presentations of sucrose while they were thirsty; the other half received sucrose while they were hungry. In Experiment 3, the same design was used but these sucrose presentations were made contingent on an instrumental response. Also in Experiment 3, the specificity of the sucrose-response preference to a shift to thirst was examined by testing under increased and decreased levels of hunger. The results of those experiments indicated that the sucrose-response preference is exhibited only under thirst and that exposure to the sucrose under thirst only marginally enhanced that preference. These findings suggest that instrumental responding may be modified by changes in the value of its outcome in the absence of experience with the revalued outcome.     

公司瑕疵决议撤销制度的溯及力问题探讨——以善意第三人利益维护为视角

公司瑕疵决议撤销制度,可以维护中小股东合法权益以及平衡大小股东之间的利益,却也容易损害信赖该决议而与公司进行交易的第三人利益。基于维护交易安全、保障交易效率和保护公共利益的需要,公司决议存在瑕疵导致被撤销的,在其溯及力问题上应注意保护股东利益与善意第三人利益的协调,在尽量尊重已发生的事实关系并注意对善意第三人保护的基础上,根据公司决议涉及的对内和对外关系而有所区别。     

The role of incentive learning in instrumental outcome revaluation by sensory-specific satiety

Hungry rats were trained to perform two instrumental actions, one for salt- and the other for lemonflavored polycose solution. When they were sated on one of these two outcomes by prefeeding immediately prior to a choice extinction test, the action trained with the prefed solution was performed less than the other action. The subsequent experiments examined the role of incentive learning in this specific satiety-induced outcome revaluation effect. The second experiment demonstrated that the experience of consuming a flavored polycose solution to satiety enabled the state induced by polycose consumption to control the devaluation of the flavored outcome. By contrast, the third study found that, although devaluing the prefed outcome, specific-satiety treatments could induce a relative inflation in the incentive value of other food outcomes. The final two studies demonstrated an increased outcome-devaluation effect in instrumental performance when these devaluation and revaluation effects were combined. Taken together, these studies demonstrate that specific satiety treatments produce changes in outcome value that depend upon incentive learning.     

A comparison between elemental and compound training of cues in retrospective revaluation

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.     

略论刑法溯及力与既判力的关系

对于刑法溯及力和既判力的关系,理论界存在不同认识,各国立法也有不同规定。不同的认识和立法体现了不同的价值取向。对二者关系采取有限的相关原则,能够在兼顾可实行性的基础上最大限度地实现刑法人权保障的价值追求。我国的相关立法规定也应加以完善。     

Simulations of a modified SOP model applied to retrospective revaluation of human causal learning

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.     

Recovery from the overexpectation effect: Contrasting performance-focused and acquisition-focused models of retrospective revaluation

In four Pavlovian conditioned lick-suppression experiments, rats had two conditioned stimuli (CSs X and A) independently paired with footshock, followed by pairings of a compound of A and X with the footshock. On subsequent tests with CS X, less conditioned suppression was observed than in control subjects that lacked the compound AX→footshock trials. Thisoverexpectation effect was reversed through posttraining extinction of CS A, a result consistent with both performance- and acquisition-focused models of retrospective revaluation. However, only performance-focused models could account for how posttraining increases or decreases in the A-footshock temporal interval attenuate the overexpectation effect.     

The propositional approach to associative learning as an alternative for association formation models

Dickinson (2009) agrees with two of the core claims that were made in my target article (De Houwer, 2009): Associative learning effects (often) depend on (1) the formation of propositions and (2) the operation of nonautomatic processes. Whereas I derived these claims from propositional models of learning, Dickinson (2009) argues that they are also compatible with association formation models (AFMs). He also defends the position that only AFMs can explain “nonrational responses to associative experiences.” In this comment, I question whether there is much value in continuing to cling to AFMs.     

Retroactive interference in rat radial maze performance: The role of point of delay interpolation and the similarity and amount of interpolated material

The conditions necessary for producing retroactive interference (RI) were examined in a 12-arm radial maze. Rats were first given either three or nine forced choices in a to-be-remembered maze. During a 2-h delay, they received one or two trials in a second 12-arm maze, located either in a different room or the same room as the to-be-remembered maze. During the postdelay memory test, RI from the interference trials was produced only when nine choices had been made in the to-be-remembered maze and two interference trials had been conducted during the delay interval. RI was not found when only three forced choices had to be retained or after a single interference trial. The similarity between the interpolated and to-be-remembered mazes had no effect on choice accuracy. It was concluded that two conditions are required for the production of RI in the radial maze. First, a “large amount” of information should be resident in working memory. Second, a substantial number of interpolated trials or choices must be made during the delay.     

构筑高职教育联盟提高办学整体效益

高等职业教育要健康发展，应坚持以内涵发展为主的原则。提高办学整体效益，构筑高职联盟是高职院校间，利益与资源共享形式的一种新形式的组合，发展之很有现实意义。     

Teacher liking as an affective filter for the association between student behavior and peer status

This study investigated how peer perceptions of teacher liking and disliking for a student shape students’ social cognitions by moderating associations between the student’s peer-perceived social behavior and peer liking and disliking status. We studied individual teacher liking and disliking as well as classroom norms as moderators of individual and classroom-level behavior-status associations. Peer nominations of (dis)liking, being (dis)liked by the teacher, and prosocial and aggressive behavior were gathered from 1454 students (M_age = 10.60) in 58 fifth-grade classes in the Netherlands. Results from multilevel analyses showed the teacher made a difference in particular for those students who were at-risk of low peer status, that is, those students who were perceived by many of their peers to show aggressive behavior and by few to show prosocial behavior. These students were disliked less and liked more when they were perceived by peers to be less disliked and more liked by the teacher. Furthermore, the amount of disliking associated with overt and relational aggression differed across classrooms, depending on norms of teacher liking. These findings may help teachers to understand and improve an individual student’s peer status, and alter the behavior–status dynamics in their class.     

Two non-traditional measures of chemistry learning: Word association and idea association

Conclusion The word association test and idea association test are open-ended tests which assess students' linking ability and also their accuracy in retrieving the relevant knowledge. These tests break through the “spoon-fed” and “drilled” types of assessment. The earlier study has shown that linkage of knowledge is one of the influential factors in determining problem solving performance (Lee, 1986). A replication study has confirmed the earlier findings that these two non-traditional measures assess learning performance as do the traditional methods. Apart from providing the numerical scores, for the learning performance, the two non-traditional tests also provide teachers with useful qualitative evidence of how students proceed with their learning and with their understanding of concepts. The technical procedures of setting, carrying out and scoring the tests are reasonably easy to handle. On the basis of the evidence shown, it is suggested that the word association and idea association tests should become part of the regular testing of chemistry learning in schools.