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: A selective extinction through cognitive evaluation (SECE) task in which information is cognitively evaluated on a trial‐by‐trial basis to ascertain the extinction contingencies is introduced, supporting the idea of common lateral prefrontal mechanisms involved in both processes.
Abstract: The extinction of a previously conditioned response can be modulated through cognitive processes, including feature-based information, and explicit instruction. Here, we introduce a selective extinction through cognitive evaluation (SECE) task in which information is cognitively evaluated on a trial-by-trial basis to ascertain the extinction contingencies. Participants were conditioned to expect an electric shock during the presentation of one of two letters (CS+/CS-). During the SECE task, the letters were presented within words belonging to two categories, one of which indicated safety (COG-_CS+ trials), while risk of shock was maintained for the other category (COG+_CS+ trials). Skin conductance responses indicated that participants reduced their response to COG-_CS+ trials compared to COG+_CS+ trials. Clusters in bilateral insula and anterior cingulate cortex showed activation for COG+_CS+ trials that was reduced for COG-_CS+ trials. A network of brain regions, including left inferior frontal gyrus, and bilateral temporal and parietal cortices showed greater activation for COG-_CS+ versus COG+_CS+ trials. This is consistent with the semantic processing and decision-making necessary to evaluate the trial contingencies. We compared activation in the SECE task to activation in a cognitive reappraisal task in which participants were asked to attend to, or regulate their emotional reactions to affective IAPS images. This task replicated prefrontal activation seen in previous reappraisal studies. A voxelwise conjunction analysis found no overlap between the cognitive reappraisal and the SECE task, but we did find evidence for common activation in follow-up ROI analyses, supporting the idea of common lateral prefrontal mechanisms involved in both processes.
3 citations
Cites background from "Probability of shock in the presenc..."
...This idea is supported by several studies investigating conditioned inhibition (Rescorla, 1969), learned safety (Pollak et al....
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...Through fear conditioning, a previously neutral stimulus (CS+) that is repeatedly paired with an aversive, unconditioned stimulus (US), elicits a conditioned response (CR) even when the US is no longer presented (Pavlov, 1927; Rescorla, 1969; Watson & Rayner, 1920)....
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16 Nov 2010
TL;DR: Medical Research Council Programme Grant; Overseas Research Studentship; Poynton Cambridge Commonwealth Trust; Oon Khye Beng Ch’hia Tsio Bursary as mentioned in this paper.
Abstract: Medical Research Council Programme Grant; Overseas Research Studentship; Poynton Cambridge Commonwealth Trust; Oon Khye Beng Ch‟hia Tsio Bursary
3 citations
Cites background from "Probability of shock in the presenc..."
...In other words, learning is influenced not only by the probability of the US in the presence of the CS, but also by the probability of the US in the absence of the CS (Rescorla, 1968)....
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01 Jan 1979
TL;DR: The need for a model of classical conditioning that predicts the effects of reinforcement and nonreinforcement on a trial-by-trial basis and accounts for the outcomes of various manipulations of the contingency between CS and UCS is stated.
Abstract: Chapter Three concluded with a statement of the need for a model of classical conditioning that predicts the effects of reinforcement and nonreinforcement on a trial-by-trial basis, accounts for the outcomes of various manipulations of the contingency between CS and UCS, and predicts the net associative effects of several different conditioning treatments given in succession. Such a model was devised by Rescorla and Wagner (1972; Wagner & Rescorla, 1972) to meet these needs, but also to explain provocative new variations in the effects of reinforcement and non-reinforcement in cases where more than one CS was presented on a trial.
3 citations
01 Jan 2007
TL;DR: Learning is an adaptive tool that improves and organism’s ability to survive in a changing environment and provides an animal with knowledge that captures the statistical relationships between different significant events that occur in the environment.
Abstract: Researchers may disagree in their theories of human and animal learning. But all of them agree at least in one thing: Learning is an adaptive tool that improves and organism’s ability to survive in a changing environment. The process of learning provides an animal with (either explicit or implicit) knowledge that captures, among many other things, the statistical relationships between different significant events that occur in the environment. This process takes place, for example, in Pavlovian conditioning experiments, in which humans and other animals learn the statistical relationship between a conditioned stimulus (CS) and an unconditioned stimulus (US) and adapt their response to the CS as a result of this experience. A similar process can be observed in experiments in which human subjects have to learn the relationship between different cues and outcomes and are asked to rate the perceived strength of those relationships.
3 citations
Cites background or methods or result from "Probability of shock in the presenc..."
...28/12/2005http://www.interdisciplines.org/causality/papers/16/printable/paper The origin of this contradiction might perhaps be found in the measure of CR that Rescorla (1968) used in his experiments....
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...Therefore, the contradiction between the Rescorla-Wagner model and Rescorla’s (1968) experiments could be due to the dependent variable used by Rescorla (1968)....
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...…trying to conclude that the Rescorla-Wagner model is wrong, but simply that there is an obvious contradiction between the experiments performed by Rescorla (1968) and the Rescorla-Wagner model, and that this contradiction has not been made explicit in the animal or the human learning literature,…...
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...As we have shown, this is contrary to the pattern of results reported by Rescorla (1968), which showed an absence of fear in that situation....
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...Rescorla (1968) found that for a given probability of the US given the CS, the conditioned response (CR) was negatively correlated with the probability of the US in the absence of the CS....
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TL;DR: The results suggest that the deficit of interactive context processing, which is a hallmark of psychotic states, might originate from a mere deficit of fundamental associative processes.
Abstract: Interactive context processing is a cognitive ability that is altered in psychotic states, including schizophrenia. This deficit has been linked to prefrontal cortical dysfunction in humans. The degraded contingency effect (DCE) is a simple form of interactive context processing by which contextual information interferes with a target conditioned stimulus for control over conditioned responding. We have previously shown that the DCE was disrupted by the muscarinic receptor antagonist atropine and that this disruption was specifically restored by cholinergic drugs displaying an antipsychotic-like profile, such as physostigmine or xanomeline. The DCE was selectively associated with an increase in Fos immunoreactivity in the medial prefrontal cortex (mPFC), an increase that was not observed in the presence of atropine. Here, we set out to test the actions of typical, atypical and potential antipsychotics on atropine-induced disruption of the DCE and the related mPFC Fos-immunoreactivity profile. Low doses of haloperidol, olanzapine, clozapine and N-desmethylclozapine reversed atropine-induced disruption of the DCE, but with different dose-dependent curves (linear shapes for haloperidol and N-desmethylclozapine, inverted U shapes for olanzapine and clozapine). The level of Fos within the mPFC paralleled the pharmacological profile of the different drugs. Compared to contingent control groups, an increased level of Fos immunoreactivity within the mPFC was observed only with doses that reversed atropine-induced disruption of the DCE. These results suggest that the deficit of interactive context processing, which is a hallmark of psychotic states, might originate from a mere deficit of fundamental associative processes. This deficit might result from a cholinergic blockade of the PFC.
3 citations
Cites background from "Probability of shock in the presenc..."
...For example, the Pavlovian degraded contingency effect (DCE), first described in rats by Rescorla (1968) is a simple and fundamental phenomenon in which the addition of unsignalled unconditioned stimuli (US, e.g. a footshock) during the contingent pairing of a target event such as a tone (the…...
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References
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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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