Probability of shock in the presence and absence of CS in fear conditioning.
01 Aug 1968-Journal of Comparative and Physiological Psychology (J Comp Physiol Psychol)-Vol. 66, Iss: 1, pp 1-5
TL;DR: 2 experiments indicate that CS-US contingency is an important determinant of fear conditioning and that presentation of US in the absence of CS interferes with fear conditioning.
Abstract: 2 experiments indicate that CS-US contingency is an important determinant of fear conditioning and that presentation of US in the absence of CS interferes with fear conditioning. In Experiment 1, equal probability of a shock US in the presence and absence of a tone CS produced no CER suppression to CS; the same probability of US given only during CS produced substantial conditioning. In Experiment 2, which explored 4 different probabilities of US in the presence and absence of CS, amount of conditioning was higher the greater the probability of US during CS and was lower the greater the probability of US in the absence of CS; when the 2 probabilities were equal, no conditioning resulted. Two conceptions of Pavlovian conditioning have been distinguished by Rescorla (1967). The first, and more traditional, notion emphasizes the role of the number of pairings of CS and US in the formation of a CR. The second notion suggests that it is the contingency between CS and US which is important. The notion of contingency differs from that of pairing in that it includes not only what events are paired but also what events are not paired. As used here, contingency refers to the relative probability of occurrence of US in the presence of CS as contrasted with its probability in the absence of CS. The contingency notion suggests that, in fact, conditioning only occurs when these probabilities differ; when the probability of US is higher during CS than at other times, excitatory conditioning occurs; when the probability is lower, inhibitory conditioning results. Notice that the probability of a US can be the same in the absence and presence of CS and yet there can be a fair number of CS-US pairings. It is this that makes it possible to assess the relative importance of pairing and contingency in the development of a CR. Several experiments have pointed to the usefulness of the contingency notion. Rescorla (1966) reported a Pavlovian 1This research was supported by Grants MH13415-01 from the National Institute of Mental Health and GB-6493 from the National Science Foundation, as well as by funds from Yale University.
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TL;DR: In this paper, the connectionist approach is compared with alternative approaches: how may we decide whether connectionism is preferable to alternative approaches, and how to choose between connectionism and alternative approaches.
Abstract: My paper is about a single problem: whether New Connectionism can provide a deeper understanding of simple forms of learning than either Behaviorism or Discrepancy Theory.1 It is a problem which should interest anyone inclined to wonder, as I do, about the prospects of connectionism as a basis for the psychology of human and animal learning, that is, to wonder whether learning is in general a connectionist process. What are the key issues, principles, data that lie behind the study of simple learning? What does connectionism say about these topics? How does the connectionist approach compare with alternative approaches: How may we decide whether connectionism is preferable to alternative approaches? A chief advantage of focusing on simple learning is that the insights gained may be cumulative and apply when complex forms of learning are studied, although except for some speculative remarks at the end of the paper, I shall have nothing to say about complex learning in this paper.
3 citations
TL;DR: The authors examined three response rules for explaining the role of temporal factors in the control of responding and found that the cycle-to-trial comparator rule was the best predictor of the pattern of responding.
Abstract: Three response rules for explaining the role of temporal factors in the control of responding were examined. These were the cycle-to-trial comparator rule from scalar expectancy theory (SET; Gibbon & Balsam, 1981), the “deletion” comparator rule proposed by Cooper, Aronson, Balsam, and Gibbon (1990), and a “bad/good” comparator rule—a type of ITI-to-trial comparator. Two of these rules were designed to explain the acquisition of responding in simple associative learning paradigms (i.e., autoshaping). Here, their generality as predictors of response levels in response-dependent multiple schedules was examined. SET’s overall cycle-to-trial comparator rule was the best predictor of the pattern of responding. Contrary to previous findings regarding contrast in multiple schedules, which show greater contrast with shorter component durations, there was no effect of absolute component duration. As predicted by SET, relative, not absolute, component durations controlled response levels.
3 citations
TL;DR: In this paper, the potential of a single subanesthetic intravenous infusion of ketamine (NMDA receptor antagonist) to enhance post-retrieval extinction of PTSD trauma memories was explored.
Abstract: NMDA receptor antagonists have a vital role in extinction, learning, and reconsolidation processes. During the reconsolidation window, memories are activated into a labile state and can be stored in an altered form. This concept might have significant clinical implications in treating PTSD. Using amygdala activity as a major biomarker of fear response, we tested the potential of a single subanesthetic intravenous infusion of ketamine (NMDA receptor antagonist) to enhance post-retrieval extinction of PTSD trauma memories. Post-extinction, ketamine recipients (vs midazolam) showed a lower amygdala and hippocampus reactivation to trauma memories. Post-retrieval ketamine administration was also associated with decreased connectivity between the amygdala and hippocampus, with no change in amygdala-vmPFC connectivity, which suggests that ketamine may enhance post-retrieval extinction of PTSD trauma memory in humans. These findings demonstrate the capacity to rewrite human traumatic memories and to modulate the fear response for at least 30 days post-extinction.
3 citations
01 Jan 2017
TL;DR: Extension of Behavioral Momentum Theory to Conditions with Changing Reinforcer Rates as mentioned in this paper ) is an extension of behavioral momentum theory to conditions with changing Reinforcer rates. But it does not consider reinforcement learning.
Abstract: Extension of Behavioral Momentum Theory to Conditions with Changing Reinforcer Rates
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Cites background from "Probability of shock in the presenc..."
...The relation between reinforcers and a target discriminative stimulus, by definition, reflects the reinforcer rate in the presence of that stimulus relative to the reinforcer rate in the absence of that stimulus (i.e., in the context within which the target stimulus appears; see Rescorla, 1968)....
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TL;DR: It has been claimed that experiments where contingency is manipulated allow us to distinguish between excitatory and inhibitory associative effects, and suggest a solution to the problem of finding a control procedure for non-associative effects.
Abstract: There is evidence to suggest that CS-US contingency is the variable that determines the associative effects of a CS. It has been claimed that experiments where contingency is manipulated allow us to distinguish between excitatory and inhibitory associative effects, and suggest a solution to the problem of finding a control procedure for non-associative effects. It is argued, however, that unless we can find a priori grounds for defining a level of contingency at which there are no associative effects, these claims are not justified. The reasons for this are that we have no way of distinguishing experimentally between associative and non-associative contributions to the effect of a CS, and that without such a technique there is no possibility of locating the point of associative neutrality empirically.
3 citations
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TL;DR: This "truly random" control procedure leads to a new conception of Pavlovian conditioning postulating that the contingency between CS and US, rather than the pairing of CS andUS, is the important event in conditioning.
Abstract: The traditional control procedures for Pavlovian conditioning are examined and each is found wanting. Some procedures introduce nonassociative factors not present in the experimental procedure while others transform the excitatory, experimental CS-US contingency into an inhibitory contingency. An alternative control procedure is suggested in which there is no contingency whatsoever between CS and US. This \"truly random\" control procedure leads to a new conception of Pavlovian conditioning postulating that the contingency between CS and US, rather than the pairing of CS and US, is the important event in conditioning. The fruitfulness of this new conception of Pavlovian conditioning is illustrated by 2 experimental results.
1,328 citations
301 citations
TL;DR: In this paper, three groups of dogs were trained with different kinds of Pavlovian fear conditioning for three different types of dogs: randomly and independently; for a second group, CSs predicted the occurrence of USs; and for a third group, S predicted the absence of the USs.
Abstract: Three groups of dogs were Sidman avoidance trained They then received different kinds of Pavlovian fear conditioning For one group CSs and USs occurred randomly and independently; for a second group, CSs predicted the occurrence of USs; for a third group, CSs predicted the absence of the USs The CSs were subsequently presented while S performed the avoidance response CSs which had predicted the occurrence or the absence of USs produced, respectively, increases and decreases in avoidance rate For the group with random CSs and USs in conditioning, the CS had no effect upon avoidance
160 citations
64 citations
TL;DR: Rats in an experimental group were given 30 trials of differential CER and then the CS+ and CS− were combined during CER extinction, resulting in less suppression for the experimental group than shown by a control group, interpreted as a demonstration of the active inhibitory properties of CS−.
Abstract: Rats in an experimental group were given 30 trials of differential CER and then the CS+ and CS− were combined during CER extinction. The combination resulted in less suppression for the experimental group than shown by a control group which had a CS+ and a formerly random stimulus combined during extinction. This was interpreted as a demonstration of the active inhibitory properties of CS−.
44 citations
"Probability of shock in the presenc..." refers background in this paper
...Although such an account is plausible for the present data, it fails to explain the active inhibition of fear found by Rescorla and LoLordo (1965), Rescorla (1966), and Hammond (1967)....
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