Robert R. Mowrer

Contemporary Learning Theories: Pavlovian Conditioning and the Status of Traditional Learning Theory

Volume I: Contents: R.R. Mowrer, S.B. Klein, Traditional Learning Theory and the Transition to Contemporary Learning Theory. Part I:Theories of Pavlovian Conditioning. P.J. Durlach, Learning and Performance in Pavlovian Conditioning: Are Failures of Contiguity Failures of Learning or Performance? R.R. Miller, L.D. Matzel, Contingency and Relative Associative Strength. A.G. Baker, P. Mercier, Attention, Retrospective Processing and Cognitive Representations. G. Hall, R. Honey, Perceptual and Associative Learning. A.R. Wagner, S.E. Brandon, Evolution of a Structured Connectionist Model of Pavlovian Conditioning (AESOP). A. Tomie, W. Brooks, Sign-Tracking: The Search for Reward. Part II:Current Status of Traditional Learning Theory. D.J. Levis, The Case for a Return to a Two-Factor Theory of Avoidance: The Failure of Non-Fear Interpretations. A. Dickinson, The Expectancy Theory of Animal Conditioning. Volume II: Contents: R.R. Mowrer, S.B. Klein. Part I:Introduction: A Contrast Between Traditional and Contemporary Learning Theory. Part II:Theories of Instrumental Conditioning. J. Allison, The Nature of Reinforcement. R.M. Church, Theories of Timing Behavior. S.F. Maier, Learned Helplessness: Event Co-Variation and Cognitive Changes. F. Vaccarino, B.B. Schiff, S.E. Glickman, A Biological View of Reinforcement. Part III:Biological Constraints in Learning. V.M. LoLordo, A. Droungas, Selective Associations and Adaptive Specializations: Food Aversion and Phobias. J. Garcia, L. Brett, K. Rusiniak, Limits of Darwinian Conditioning. A.L. Riley, C.L. Wetherington, Schedule-Induced Polydipsia: Is the Rat a Small Furry Human? W. Timberlake, G.A. Lucas, Behavior Systems and Learning: From Misbehavior to General Principles.

Latent Inhibition of Contextual Stimuli Reduces the US Preexposure Effect in Rats

Two experiments are reported which utilized latent inhibition of contextual stimuli prior to administering unsignaled presentations of the Us in an attempt to further assess the role of contextual stimuli in the US preexposure effect. Specifically in Experiment 1, rats received either 0-, 5-, 10-, or 15-minute exposure to the context in which the unsignaled Uss were to occur (latent inhibition). Following preexposure to the US, animals were trained in a CER paradigm with a tone CS. Measures of suppression to the tone indicated that the greatest US preexposure effect occurred in the 0 group and that no US preexposure effect was evident in the 15 group. Experiment 2 includec two important control groups which were omitted in Experiment 1 (no US preexposures) and an additional dependent variable (time to initiate licking) to measure fear to contextual stimuli. These results are discussed in terms of the role context conditioning may play in US preexposure.

Mechanisms for the cueing phenomenon: The addition of the cueing context to the training memory ☆

Abstract A series of three experiments was run to test the hypothesis that when animals are exposed to a cue from prior training, the context in which cueing occurs becomes associated with the training memory. The first experiment demonstrates that when rats are trained to avoid in one context and then are tested in a different context performance is reduced. Experiments 2 and 3 demonstrate that this performance deficit can be alleviated by cueing the rats in the test context prior to testing. The data suggested that the improved performance does not seem to result from the association of the cueing context with a fear response. These results are discussed in relation to the context addition hypothesis.

An extinction trial as a reminder treatment following electroconvulsive shock

Animals given electroconvulsive shock (ECS) following active avoidance training were found to exhibit poor retention of the active avoidance response. However, this deficit was alleviated if the animals received an extinction trial for active avoidance prior to retention testing. That the trial was an extinction trial was demonstrated by the fact that exposure to the trial decremented the performance of animals not given ECS after learning. The implications of these findings for explanations of retrograde amnesia are discussed.

The influence of context and UCS intensity on the UCS preexposure effect in a flavor aversion paradigm

Abstract Three studies were conducted to evaluate the influence of environmental context and UCS preexposure intensity on the acquisition of a flavor aversion. In the first study, rats were exposed to two UCS-alone presentations at one of three dose levels of LiCl. The rats were given the two UCS preexposures in one of two contexts (familiar or novel). Following the UCS-alone treatment, all of the subjects received two pairings of sucrose and LiCl (1.25 meq) in the familiar context. Animals receiving UCS preexposures in the same context as used during conditioning consumed significantly more sucrose than did saline control animals. In contrast, the influence of prior UCS preexposure was not evident when UCS preexposure was experienced in a context different from that experienced during conditioning. In Experiment 2, all animal received UCS preexposure and conditioning in the novel room. Animals received either two or four preexposures at 0, 1.25, or 3.75 meq dose of LiCl. Two UCS preexposures at 3.75 meq dose produced a stronger UCS preexposure effect than did the 1.25 meq dose. Animals in Experiment 3 received two exposures to either 0-, 1.25-, or 3.75-meq LiCl in one of two contexts, followed by conditioning with the 1.25-meq LiCl dose in the same context as preexposure. Greater UCS interference occurred in animals preexposed to LiCl in the novel rather than familiar environment, with no specific dose effects in either context. These observations are discussed in terms of context blocking and generalization decrement models of the UCS preexposure effect.

Effects of cuing in an “irrelevant” context

Normally, retention of an avoidance response by a rat is impaired when the test context is novel or does not correspond to the training context. Experiment 1 demonstrates that such an impairment of test performance can be alleviated if a rat receives a cuing treatment or reminder of training in the novel test context prior to testing. Experiment 2 indicates that when rats receive avoidance training in one context and then receive a reminder of training in a novel context, they perform more poorly when tested in the training context than do animals that receive no reminder. This finding is discussed in relation to current theories of contextual influence over retention performance.

Cue-induced memory interference in the rat

Rats were trained on passive avoidance and then active avoidance, and then were tested for retention of the active response. Prior passive training interfered with retention of the active response if all training and testing occurred in one context. Significantly less interference resulted when the passive avoidance context differed from that used for active training and testing. However, significant interference did result when animals given passive training in a different context were reminded of this training in the active avoidance context prior to active avoidance training.

Enhancement of Short-Term Retention in Rats with Pretest Cues: Effects of the Training-Cueing Interval and the Specific Cueing Treatment

The present studies represent an initial analysis of variables controlling cueing effects in a short-term retention paradigm. In the first two experiments, retention performance by rats in a delayed alternation paradigm was shown to decrease as the delay interval was lengthened. In both experiments, a pretest cueing procedure was shown to reduce this retention deficit; however, the effectiveness of the cueing procedure did not change as a function of the acquisition-cueing interval. In Experiment 3 it was demonstrated that the specific cueing procedure used in Experiments 1 and 2 was more effective in alleviating forgetting than was exposure to the cues an animal normally encounters on a retention test. This latter finding was offered as a possible explanation for the results of Experiments 1 and 2.

Backward Second-Order Conditioning in Flavor Aversion Learning

Three experiments are reported which addressed the possibility that a neutral-flavor stimulus (CS2) can become aversive by pairing it with a previously established aversive-flavor stimulus (CS1). Unlike previous higher-order conditioning studies in which CSl followed CS2 (CS2-CS1 pairings), the present studies reversed this order (CS1-CS2 pairings) to determine the extent that backward second-order conditioning produces an aversion to CS2. In Experiment 1, rats received zero, one, or three pairings of a walnut-flavored solution (CS1) with LiCI. The walnut flavor was then presented just prior to forced consumption of a neutral lemon-flavored solution (CS2). A significant aversion developed to lemon only when three walnut-LiCI pairings were used. Experiment 2 manipulated the flavors used as CS1 and CS2 (lemon or walnut). Results indicated that regardless of the flavors used, a significant aversion developed to CS2 as a result of CS1-CS2 pairings. In Experiment 3, the level of aversion to CS2 with the backward higher-order conditioning paradigm was compared to forward higher-order conditioning. An unconditioned stimulus (UCS) alone treatment and a handling control treatment were included to evaluate the level of neophobia to novel flavors. Results showed that the percentages of CS2 (lemon) flavor consumed relative to total consumption was significantly lower in the backward higher order conditioning group than in the UCS alone and handling control treatments. The forward higher-order conditioning group was quite variable and differed from the control groups at the.08 level. These findings are discussed in terms of higher-order conditioning and flavor aversion learning.

A Cuing Treatment Reestablishes the US Preexposure Effect Following Context Change

A single experiment is reported in which a cuing treatment is used to transfer the US preexposure effect from one context to another. All rats received exposure to unsignaled footshocks in context B or C and then received CSUS pairings in the same context (B). Results indicated that animals receiving preexposure and training in the same context (B-B) evidenced the US preexposure effect (attenuated conditioning to the CS), whereas animals in the context change (C-B) condition failed to evidence the US preexposure effect. Importantly, animals preexposed in C and receiving a cuing treatment in the new context (B) prior to CS-US pairings did not differ from animals receiving all treatments in the same context. Thus, cuing resulted in animals behaving as though the unsignaled US presentations had occurred in the new context (B). These results are discussed in terms of the effect of cuing on the modification of memory attributes.