Discriminated avoidance vs classical conditioning: A two-phase model analysis

The acquisition of discriminated avoidance and classically conditioned leg flexions in dogs and of discriminated avoidance leg flexion in cats was examined via a two-phase model of conditioning. Classically conditioned Ss uniformly required two operators during Phase 2, with the limit of the CR operator being greater than that of the CR operator. Not all avoidance-trained Ss required two operators during Phase 2, but those who did also had a higher CR than CR operator limit. The CR operator limit was higher for avoidance than for classical training, while the change rate was greater for classical training. The avoidance behavior of cats paralleled that of the dogs. It was concluded that the data generally conformed to views of Hilgard and Marquis and, more recently, of Bolles, but were contrary to what would be expected from two-factor theory.     

Exploring a latent cause theory of classical conditioning

We frame behavior in classical conditioning experiments as the product of normative statistical inference. According to this theory, animals learn an internal model of their environment from experience. The basic building blocks of this internal model are latent causes-explanatory constructs inferred by the animal that partition observations into coherent clusters. Generalization of conditioned responding from one cue to another arises from the animal's inference that the cues were generated by the same latent cause. Through a wide range of simulations, we demonstrate where the theory succeeds and where it fails as a general account of classical conditioning.     

Savings in classical conditioning in the rabbit as a function of extended extinction

In the present experiments, savings phenomena following a limited amount of initial acquisition and extended extinction were examined. Experiments 1 and 2 compared rates of reacquisition following brief acquisition and various amounts of extinction in conditioning of the rabbit’s nictitating membrane and heart rate response, respectively. Experiment 3 compared rates of acquisition to a novel stimulus (e.g., light) following brief acquisition and various amounts of extinction to another stimulus (e.g., tone). In addition, in Experiment 3 recovery of responding to the extinguished stimulus during acquisition to the novel, cross-modal stimulus was examined. Experiments 1, 2, and 3 demonstrated that with a limited number of acquisition trials (1) there was a graded reduction in the rate of reacquisition as a function of the number of extinction trials in both conditioning preparations, (2) there was a graded reduction in the rate of cross-modal acquisition as a function of the number of extinction trials, but (3), in Experiment 3, recovery of responding to the extinguished stimulus during cross-modal training of the novel stimulus appeared uniformly robust even in the face of extended extinction.     

Effects of US parameters on classical conditioning of cat hindlimb flexion

Unconditioned stimulus (US) intensity and duration were manipulated to determine their effects on cat hindlimb flexion conditioning. Seven consecutive days of acquisition training of a hindlimb flexor response to a tone conditioned stimulus (CS) were followed by 2 days of extinction. Eight animals in each of 12 groups received a 1-, 2-, 3-, or 4-mA, 60-Hz shock delivered to the right hindleg for 25, 50, or 100 msec as the US. Analysis of conditioned-response (CR) frequency indicated that conditioned responding was a positive function of both the intensity and duration of shock, although these variables did not interact with one another. CR latency and amplitude were decreased and increased, respectively, by increases in US intensity. The pattern of results reported here may support a contiguity notion of conditioning, and are discussed in the context of other conditioning preparations.     

Transfer across CS-US intervals and sensory modalities in classical conditioning of the rabbit

Two experiments investigated transfer of the rabbit’s conditioned nictitating membrane response (NMR) from shorter to longer CS-US intervals in conjunction with a change in CS modality, for example, light to tone. In Experiment 1, three experimental groups received initial training with a 400-msec CS-US interval, which produced substantial CR acquisition, and three control groups received initial training with a 2,800-msec CS-US interval, which produced minimal CR acquisition. Subsequently, the experimental and control groups received training with an 800-, 1,800-, or 2,800-msec CS-US trace interval. At the same time, the modality of the CS was changed from tone to light (or vice versa). Experiment 2 contained three groups that received initial exposure to a 400-msec CS-US interval, a 2,800-msec CS-US interval, or just the experimental chambers. Subsequently, all three groups received training with an 800-msec CS-US interval in a different CS modality. The results of both experiments revealed substantial positive transfer across CS modalities from the 400-msec CS-US interval to the 800-msec CS-US interval. There was also significant transfer to the 1,800-msec but not the 2,800-msec CS-US interval. The transfer did not appear immediately on test presentations of the second CS. Rather, the transfer appeared as an enhancement in the rate of CR acquisition after reinforced training with the second CS had commenced. The results are discussed with respect to mechanisms of transfer and facilitation of trace conditioning.     

经典力学的波动模型

根据物质的波—粒二象性,描述粒子性的经典力学方程应有与之对应的波动模型。经理论推导,得出了作用于物体的外力和德布罗意波波长、频率之间的关系以及一些很有意义的物理结论。同时导出了一系列动力学和运动学方程的波动形式。     

Summation and configuration between and within sensory modalities in classical conditioning of the rabbit

Three experiments examined “atomistic” and “configurai” processes in stimulus compounding using the rabbit’s conditioned nictitating membrane response. Two conditioned stimuli (CSs) were trained separately and then tested together in a compound. Animals trained with CSs from different modalities—namely, tone and light—showed summation in both acquisition and extinction. That is, the probability of a response to the compound could be predicted by the statistical sum of responding to the CSs. In contrast, animals trained with CSs from the auditory modality, tone and noise, showed a level of responding to the tone + noise compound that was the same as that of the CSs, well under the level predicted by the statistical sum of responding to the CSs. In conclusion, atomistic processes appear to predominate in cross-modal compounding. Configurai processes may occur during compounding within the auditory modality, but atomistic alternatives—namely, common elements and selective attention hypotheses—may be able to explain the results.     

Biological constraints on instrumental and classical conditioning: Retrospect and prospect

The adequacy of traditional approaches to the study of animal learning to account fully for learning phenomena has been seriously questioned during the past decade. Critics of traditional analyses advocated a biological orientation to the interpretation of associative processes and introduced a variety of concepts intended to provide a new framework for the study of animal learning. This promise of a reorientation of the field has not been realized. The concepts of biological constraints, adaptive specializations, and situation specificity of learning have had a less profound influence on the general process approach to instrumental and classical conditioning than anticipated. The present paper makes explicit the conceptual bases of the original biological approaches to learning, identifies reasons why they failed to change fundamentally the study of instrumental and classical conditioning, and proposes an alternative approach to the use of ecological and evolutionary principles in studies of conditioning. We suggest a renewed comparative approach to the study of learning phenomena that avoids many of the difficulties inherent in earlier formulations by providing (1) a strategy for the discovery of adaptive specializations in learning, (2) an ecological framework for the discussion of these adaptive specializations, and (3) a renewed emphasis on the study of species differences in learning.     

Positive and negative patterning in human classical skin conductance response conditioning

Three experiments on classical differential conditioning of the human skin conductance response to elemental and compound stimuli are reported. Subjects in Experiment 1 received both positive and negative patterning training, followed by either positive or negative patterning transfer tests on new stimuli. In positive patterning, a compound of two stimuli is reinforced and its elements are nonreinforced. In negative patterning, the elements are reinforced and the compound is nonreinforced. Subjects in Experiments 2 and 3 received either positive or negative patterning during training, followed by transfer tests on new stimuli. In Experiment 2, the transfer series began with new elements, after which their compound was presented; in Experiment 3, the new compound was presented first in the transfer series, and then the separate elements were administered. All three experiments provided evidence of the acquisition of positive patterning, while negative patterning was found only in Experiments 2 and 3. Positive patterning transferred to new stimuli, indicating that it was not attributable solely to summation of sub-threshold excitation conditioned to the elements on reinforced compound trials. This finding, coupled with the negative patterning found in Experiments 2 and 3, provided support for the unique cue hypothesis. It was concluded that the assumed unique cue constituted a learned “rule,” and that the actual elemental stimuli were neither perceptually nor otherwise modified during the conditioning process.     

Applying Konorski’s model of classical conditioning to signal-centered behavior in the rat: Some functional similarities between hunger CRs and sign-tracking

Two experiments were conducted to investigate functional similarities between “hunger CRs” of Konorski’s (1967) model of appetitive classical conditioning and sign-tracking behavior in rats. Konorski’s model predicts that hunger CRs will be facilitated (1) when a nonrein-forced stimulus similar to the reinforced CS is introduced, and (2) when some CS presentations are unexpectedly nonreinforced. In Experiment 1, hungry rats acquired a leverpress response to a retractable lever that was paired with response-independent food. Following this training, a second lever was introduced whose presentation was not followed by food. The effect of the presence of this second lever was to facilitate responding to the original lever. In Experiment 2, single-lever autoshaping training was followed by a shift from 100% pairing of the lever with food to only 50% of the lever presentations being followed by food. The introduction of partial reinforcement produced an immediate and durable increase in leverpressing. The findings of both experiments are consistent with predictions from Konorski’s model of classical conditioning if sign-tracking is considered as a “hunger CR.”     

Cross-modal transfer as a function of initial training level in classical conditioning with the rabbit

Initial reinforced training with a conditioned stimulus (CSA) from one sensory modality subsequently facilitates the rate of acquisition of the rabbit’s nictitating membrane response to a second conditioned stimulus (CSB) from a different sensory modality. In Experiment 1, the level of transfer was a direct function of the number of CSA-US pairings (0, 15, 30, 60, and 120). In Experiment 2, cross-modal transfer appeared to be maximal after initial training was conducted to a performance criterion as small as two CRs to CSA. The results are discussed with respect to theories of transfer, particularly a layered network model of conditioning that suggests that CR acquisition to each CS depends on two sequentially organized associations, one unique to the CS and one that is common to all associations involving the target response system.     

Evaluating conditioning of related and unrelated stimuli using a compound test

Three experiments used a compound test procedure to evaluate whether superior conditioning results from the pairing of stimuli that are related to each other. In each case, a stimulus compound was tested after its component conditioned stimuli (CSs) had been conditioned by the same unconditioned stimuli (USs) arranged such that either related or unrelated CSs and USs were paired. Experiment 1 explored auditory and gustatory stimuli conditioned by LiCl or shock, using rats. Experiments 2 and 3 used second-order conditioning in pigeons to pair stimuli that were similar by virtue either of qualitative features or of shared physical location. In each case, the compound test provided clear evidence that pairing related stimuli produces superior associative learning.     

The effect of US omission in classical aversive and appetitive conditioning of rabbits

Rabbits (Oryctolagus cuniculus) were given either a 100% or a 50% reinforcement schedule in classical conditioning. Two groups received an aversive US (shock) and two groups received an appetitive US (water to the oral cavity). With parameter estimates for the two-phase model serving as the dependent variables, it was possible to define more precisely the effect of US omission with the intermittent reinforcement schedule. For the aversive preparation, the major effect of intermittent reinforcement was to increase the duration of Phase 1, a phase during which response likelihood remains constant at its initial value. Only a small proportion of subjects reflected the effect of US omission during Phase 2, the “learning” phase, this being a low operator limit following trials on which neither the CR nor the US occurred. The major effect of US omission for the appetitive preparation was in Phase 2, primarily a result of a minority of subjects having a low operator limit following trials on which neither the CR nor the US occurred. Many subjects required separate operators for trials on which the CR did or did not occur. The results were interpreted to pose difficulties for strength theories of conditioning, and the limitation implied for successful application of the Rescorla-Wagner theory are discussed. The implications of the data for response-contingent interpretations and for individual differences are also discussed.     

Cross-modal transfer as a function of similarities between training tasks in classical conditioning of the rabbit

The present experiments examined transfer of training from visual to auditory sensory modalities in classical conditioning of the rabbit’s nictitating membrane response. Experiment 1 examined transfer from initial training with a single visual CS to subsequent auditory discrimination training, and Experiment 2 examined transfer from visual discrimination training to auditory discrimination training. The major findings were that (1) initial conditioning of a visual CS facilitated the overall rate of CR acquisition to the auditory CSs separate from the requirements for discrimination learning (Experiments 1 and 2), and (2) initial visual discrimination training facilitated auditory discrimination learning (Experiment 2). Thus, the animals appeared to encode separately both contiguous CS-US relations and CS+ versus CS? relations during initial visual training. The results are discussed with respect to theories of extradimensional transfer.     

Temporal discrimination using different feature-target intervals in classical conditioning of the rabbit’s nictitating membrane response

In a typical conditional discrimination, a target stimulus (X) is reinforced during one feature cue (A→X+), but not during another feature cue (B→X−). The present experiments used only a single “feature” cue (a 66-sec tone). On half of the trials, the target stimulus (a 400-msec light) was paired with the reinforcer when the feature-target interval was one duration (e.g., 5 sec). On the remaining trials, the interval was different (e.g., 45 sec), and the target stimulus was presented without the reinforcer. All the animals acquired this temporal discrimination, and subsequent testing with other feature-target intervals yielded generalization-like gradients. These results provide solid evidence that each portion of a feature cue is encoded in a distinctive fashion. Had temporal encoding not occurred, the feature cue would have been just as ambiguous a predictor of the reinforcer as was the target stimulus, and discrimination would not have been possible. The integration of real-time temporal encoding mechanisms into models of conditional discrimination is discussed.     

Classical-classical transfer: Excitatory associations between “competing” motivational stimuli during classical conditioning of the rabbit

A sensory preconditioning analogue was employed to separate signaling effects from motivational effects observed in appetitive-to-aversive transfer of training. Rabbits received appetitive conditioning (tone-water pairings) of the jaw-movement response, followed by aversive conditioning of the nictitating membrane response, during which water delivery served as the CS for para-orbital shock. When the tone was subsequently presented, only subjects exposed to both sets of pairings demonstrated conditioned jaw movement and nictitating membrane responses. The occurrence of both responses to the tone is inconsistent with the action of reciprocal inhibition between motivational states. The results are interpreted in terms of multiple mediators for transfer-of-training paradigms.     

Motivational vs. associative role of the US in classical conditioning of the rabbit’s nictitating membrane response

Two experiments tested the motivational role of the US in classical conditioning of the rabbit’s nictitating membrane (NM) response. In Experiment 1, subjects were trained to an intermediate performance level and then given a series of (1) CS-US trials, (2) “backwards” US-CS trials, (3) CS-alone trials, (4) US-alone trials, or (5) no-stimulus presentations. Interpolated presentations of the US, either alone or in a backwards contingency, tended to produce an impairment of subsequent acquisition. In Experiment 2, subjects were trained with strong or weak US intensity on paired or interpolated trials. US intensity on interpolated trials had only a very small effect, whereas the effect of US intensity on paired trials was quite large. Shifts in paired-trial US intensity produced corresponding shifts in performance, but shifts in the intensity of the interpolated US produced no apparent effect. We conclude that the arousal of motivation is not sufficient to maintain performance in classical NM conditioning.     

基于偏差分析的评教模型

传统的学生评教,评价结果单一只能用于判定教师效能,无法充分发挥评教的作用.文章提出的偏差评教模型计算出不同指标群下评价值与评价均值的偏差,并利用一向量从班级内、课程内、课程间三个不同角度给出评教结果.该模型用于实例分析能为学校课程安排、学生选课提供参考信息,具有一定的现实意义.