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: It is demonstrated that rats can segment the streams using the frequency of co-occurrence (not transitional probabilities, as human infants do) among items, showing that some basic statistical learning mechanism generalizes over nonprimate species.
Abstract: Statistical learning is one of the key mechanisms available to human infants and adults when they face the problems of segmenting a speech stream (Saffran, Aslin, & Newport, 1996) and extracting long-distance regularities (Gomez, 2002; Pena, Bonatti, Nespor, & Mehler, 2002). In the present study, we explore statistical learning abilities in rats in the context of speech segmentation experiments. In a series of five experiments, we address whether rats can compute the necessary statistics to be able to segment synthesized speech streams and detect regularities associated with grammatical structures. Our results demonstrate that rats can segment the streams using the frequency of co-occurrence (not transitional probabilities, as human infants do) among items, showing that some basic statistical learning mechanism generalizes over nonprimate species. Nevertheless, rats did not differentiate among test items when the stream was organized over more complex regularities that involved nonadjacent elements and abstract grammar-like rules.
199 citations
TL;DR: This article showed that human performance can be systematically improved or degraded by varying whether a correct solution requires one to compute hit and false-alarm rates over natural units, such as whole objects, as opposed to inseparable aspects, views, and other parsings that violate evolved principles of object construal.
Abstract: Evolutionary approaches to judgment under uncertainty have led to new data showing that untutored subject reliably produce judgments that conform to may principles of probability theory when (a) they are asked to compute a frequency instead of the probability of a single event, and (b) the relevant information is expressed as frequencies. But are the frequencycomputation systems implicated in these experiments better at operating over some kinds of input than others? Principles of object perception and principles of adaptive design led us to propose the individuation hypothesis : that these systems are designed to produce wellcalibrated statistical inferences when they operate over representations of “whole” objects, events, and locations. In a series of experiments on Bayesian reasoning, we show that human performance can be systematically improved or degraded by varying whether a correct solution requires one to compute hit and false-alarm rates over “natural” units, such as whole objects, as opposed to inseparable aspects, views, and other parsings that violate evolved principles of object construal. The ability to make well-calibrated probability judgments depends, at a very basic level, on the ability to count. The ability to count depends on the ability to individuate the world: to see it as composed of discrete entities. Research on how people individuate the world is, therefore, relevant to understanding the statistical inference mechanisms that govern how people make judgments under uncertainty. Computational machinery whose architecture is designed to parse the world and make inferences about it is under intensive study in many branches of psychology: perception, psychophysics, cognitive development, cognitive neurosci
198 citations
Cites background from "Probability of shock in the presenc..."
...Every organism that can learn via classical or operant conditioning can estimate rates – number per unit time – and use them to compute conditional probabilities in what amounts to a natural sampling scheme (Gallistel, 1990; Kleiter, 1994; Rescorla, 1967, 1968; Staddon, 1988)....
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...(See Gallistel, 1990; Rescorla, 1967, 1968; Staddon, 1988.)...
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TL;DR: In this paper, the authors outline an emergentist account whereby the limited end-state typical of adult second language learners results from dynamic cycles of language use, language change, language perception, and language learning in the interactions of members of language communities.
Abstract: This article outlines an emergentist account whereby the limited end-state typical of adult second language learners results from dynamic cycles of language use, language change, language perception, and language learning in the interactions of members of language communities. In summary, the major processes are:
1. Usage leads to change: High frequency use of grammatical functors causes their phonological erosion and homonymy.
2. Change affects perception: Phonologically reduced cues are hard to perceive.
3. Perception affects learning: Low salience cues are difficult to learn, as are homonymous/polysemous constructions because of the low contingency of their form–function association.
4. Learning affects usage: (i) Where language is predominantly learned naturalistically by adults without any form focus, a typical result is a Basic Variety of interlanguage, low in grammatical complexity but communicatively effective. Because usage leads to change, maximum contact languages learned naturalistically can thus simplify and lose grammatical intricacies. Alternatively, (ii) where there are efforts promoting formal accuracy, the attractor state of the Basic Variety can be escaped by means of dialectic forces, socially recruited, involving the dynamics of learner consciousness, form-focused attention, and explicit learning. Such influences promote language maintenance.
Form, user, and use are inextricable.
197 citations
Cites background from "Probability of shock in the presenc..."
...…many parallels between the grammatical structures of French-based creoles and the Basic Variety of interlanguage of learners of French as an L2, particularly in the 1:1 iconicity of their mapping of function and form (Andersen, 1984), their controller-first, focus-last constituent ordering…...
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...Homophonous (Low Form-Function Contingency) Forms Are Poorly Learned Learning the associations between cues and outcomes is a function of their contingency (Rescorla, 1968)....
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TL;DR: This work uses fear conditioning as a paradigmatic case and proposes an alternative model in which mnemonic processing is allocated to specific circuits through a dynamic process, in which alternate circuits compensate when these 'primary' circuits are compromised.
194 citations
01 Jan 1971
TL;DR: In this paper, the authors present the current status of the concept of fear from a consistent viewpoint and discuss four index responses that permit a clear conceptual separation between the fear response and the response used as its index.
Abstract: Publisher Summary
This chapter presents the current status of the concept of fear from a consistent viewpoint. Fear was considered to be a classically conditioned response, defined in terms of the prior appropriate pairing of neutral and noxious stimuli. As fear is unobservable, it may be measured only by its effect on other observable responses. Owing to this state of affairs, it is necessary, in studying fear, to maintain a clear conceptual separation between the fear response and the response used as its index. The chapter discusses four index responses that permit such a distinction. The chapter reviews the conditioning, measurement, and definition of fear. It focuses on aversive learning situations in which the conditioning of fear and its measurement are generally considered to be independent. Specifically, the interest will be in situations in which the noxious unconditioned stimulus is usually assumed to have its effect on the conditioning of fear but not directly on the measured response. The chapter describes four measures of fear and discusses some of the strengths and weaknesses of each measure and a theoretical rationale for the use of each as an index of fear.
185 citations
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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