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Journal ArticleDOI

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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Journal ArticleDOI
TL;DR: In this article, a truly random sequence of tone CSs and shock USs were given to groups of rats, then conditioned fear to the CS was measured using a conditioned suppression procedure.
Abstract: Truly random sequences of tone CSs and shock USs were given to groups of rats, then conditioned fear to the CS was measured using a conditioned suppression procedure. Subjects exhibited an excitatory CR to the CS following truly random training independently of whether or not a background white noise continued through the presentation of the CS during conditioning and testing. It was concluded that the presence of the white noise during the CS did not block excitatory conditioning to the CS as had been predicted by Rescorla (1972).

3 citations

27 Dec 2019
TL;DR: The current study shows that blocking inhibition in the ventral tegmental area or inactivating the nucleus accumbens neurons during compound cue conditioning attenuates Kamin blocking, and that goal tracking rats, in which expected rewards have previously been shown to evoke a robust dopamine response, did not express the Kaminblocking effect.
Abstract: The overall aim of the research described in this thesis is to identify neural substrates underlying the Kamin blocking effect. This phenomenon is crucial for understanding of the neural mechanisms of associative learning. Kamin blocking refers to the finding that conditioned responding to a cue is attenuated when it is paired with a reinforcer in the presence of another cue which has previously been conditioned using that reinforcer. The blocking effect suggests that associative learning is driven by prediction errors, and is not based purely on temporal contiguity between events. In the context of appetitive classical conditioning, recent evidence suggests that the ventral tegmental area and the nucleus accumbens play a role in computing reward prediction error. The current study shows that blocking inhibition in the ventral tegmental area or inactivating the nucleus accumbens neurons during compound cue conditioning attenuates Kamin blocking. Inactivating the nucleus accumbens during single cue conditioning also attenuates Kamin blocking. Taken together, these findings suggest that inhibition in the ventral tegmental area, inhibitory output from the nucleus accumbens, and learning in the nucleus accumbens play crucial roles in the Kamin blocking effect. Previous studies show that dopamine transients track the theoretical reward prediction error during appetitive classical conditioning, and the reduction in the dopamine response evoked by the reward when it is expected has been suggested to play a role in the Kamin blocking effect. In support of this hypothesis, the current study also found that goal tracking rats, in which expected rewards have previously been shown to evoke a robust dopamine response, did not express the Kamin blocking effect. Conversely, sign trackers, in which expected rewards evoke a diminished dopamine response, expressed the blocking effect. These findings are discussed in relation to psychological theory of learning and the possible underlying neural mechanisms.

3 citations


Cites background from "Probability of shock in the presenc..."

  • ...Rescorla (1968) argued that contingency between the CS and the US plays an important role in determining the strength of the CR. Rescorla (1968) found that conditioning depends on the probability of US given the CS and probability of the US in the absence of the CS....

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Posted ContentDOI
08 Feb 2021-bioRxiv
TL;DR: In this article, a continuous time Markov renewal process model of the state space is proposed to explain animal behavior in the context of reinforcement learning (RL) and reinforcement learning is applied to real animals.
Abstract: A key concept in reinforcement learning (RL) is that of a state space. A state space is an abstract representation of the world using which statistical relations in the world can be described. The simplest form of RL, model free RL, is widely applied to explain animal behavior in numerous neuroscientific studies. More complex RL versions assume that animals build and store an explicit model of the world in memory. To apply these approaches to explain animal behavior, typical neuroscientific RL models make assumptions about the underlying state space formed by animals, especially regarding the representation of time. Here, we explicitly list these assumptions and show that they have several problematic implications. We propose a solution for these problems by using a continuous time Markov renewal process model of the state space. We hope that our explicit treatment results in a serious consideration of these issues when applying RL models to real animals.

3 citations

Journal Article
TL;DR: It is argued that these primitives and importantly causal generalization can be studied within an animal learning framework and provide a normative framework for studying causal cognition.
Abstract: Theories of causal cognition describe how animals code cognitive primitives such as causal strength, directionality of relations, and other variables that allow inferences on the effect of interventions on causal links. We argue that these primitives and importantly causal generalization can be studied within an animal learning framework. Causal maps and other Bayesian approaches provide a normative framework for studying causal cognition, and associative theory provides algorithms for computing the acquisition of data-driven causal knowledge.

3 citations


Cites background from "Probability of shock in the presenc..."

  • ...Pavlovian conditioning involves animals being sensitive to or computing the overall rates or probabilities of the US in presence and the absence of the CS (see also Rescorla, 1968; 9)....

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References
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Journal ArticleDOI
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

Journal ArticleDOI
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

Journal ArticleDOI
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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