scispace - formally typeset
Search or ask a question
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.

Content maybe subject to copyright    Report

Citations
More filters
01 Jan 2014
TL;DR: In this article, a respeito das relacoes entre as funcoes reforcadora e discriminativa, tais como estudos that utilizaram o procedimento de observacao, is discussed.
Abstract: Reforco condicionado, tema de estudos ha mais de 60 anos, e um estimulo que tem sua funcao reforcadora estabelecida a partir da relacao de contingencia com outro reforcador. No entanto, apesar da simplicidade da definicao, diferentes e refinadas metodologias sao utilizadas para investigar os efeitos de reforcadores condicionados, o que, consequentemente, ocasiona em diferentes medidas. Alguns estudos tem investigado as relacoes entre as funcoes reforcadora e discriminativa, tais como estudos que utilizaram o procedimento de observacao. O objetivo do presente trabalho e apresentar alguns estudos tradicionais sobre o tema a fim de discutir a respeito das relacoes entre as funcoes reforcadora e discriminativa. Questiona-se a respeito da participacao do estimulo reforcador em uma contingencia S-S e tambem em uma contingencia triplice enquanto condicao necessaria ou suficiente para se estabelecer um reforcador condicionado. Os resultados dos estudos apontam para a relevância da funcao discriminativa, assim como de outras variaveis, como a contingencia S-S, para o estabelecimento da funcao reforcadora, porem indicam que a funcao discriminativa nao e condicao necessaria para o estabelecimento da funcao reforcadora. Estas discussoes proficuas direcionam para a importância da realizacao de pesquisas adicionais sobre o assunto com o objetivo de integrar e consolidar os resultados ja existentes na literatura.

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

  • ...No procedimento padrão utilizado por Rescorla (1967; 1968; 1988), uma resposta operante que produz reforço primário é treinada em uma condição inicial....

    [...]

  • ...No entanto, neste estudo, as relações de contingência e contiguidade não foram manipuladas diretamente como no estudo de Rescorla (1968)....

    [...]

  • ...Estes resultados corroboram os resultados de Rescorla (1968) utilizando estimulação aversiva, e apontam para a importância da relação de contingência S-S entre os estímulos não só para o estabelecimento da função reforçadora negativa, mas também para o estabelecimento da função discriminativa....

    [...]

  • ...Os estudos acima (Meaulders & cols., 2010; Murphy & Baker 2004; Rescorla, 1968) salientam que o emparelhamento é relevante, porém aspectos além deste podem também ser responsáveis pelo condicionamento de um estímulo, como a relação de contingência entre o estímulo inicialmente neutro e outro…...

    [...]

  • ...Essas noções encontram embasamento nas evidências de que apenas o pareamento ou contiguidade entre estímulos não é suficiente para a ocorrência de condicionamento (Rescorla, 1968)....

    [...]

01 Jan 2014
TL;DR: In this paper, a reforco condicionado, tema de estudos ha mais de 60 anos, and um estimulo que tem sua funcao reforcadora estabelecida a partir da relacao de contingencia c...
Abstract: Resumen pt: Reforco condicionado, tema de estudos ha mais de 60 anos, e um estimulo que tem sua funcao reforcadora estabelecida a partir da relacao de contingencia c...
Journal ArticleDOI
TL;DR: In this article , the authors discuss the need for maior participação of contribuições in the context of the evaluation of comportamento and the model of seleção by consequências.
Abstract: Resumo Considerando-se as recentes discussões sobre a definição de comportamento e do modelo de seleção por consequências conduzidas por pesquisadores brasileiros, discutimos a necessidade de maior participação das contribuições da análise experimental do comportamento no debate de conceitos da área e mais interação da área com outros sistemas em Psicologia. Criticamos o isolamento em relação à produção de conhecimento de outras áreas e a adoção de figuras de autoridade a partir da qual se possa fazer a avaliação das novidades da área. Para tanto, a análise do contexto no qual Skinner propôs seu modelo de seleção por consequências precisa ser feita para clara compreensão das contribuições mais importantes dessa proposta. Mostramos que a discussão sobre a distinção operante-respondente e a pertinência da noção de metacontingências são exemplos de revisão conceitual feita com base em dados e articulação entre áreas de pesquisa com epistemologias e metodologias diferentes, mas possíveis de serem articuladas.
Dissertation
01 Jan 2011
Dissertation
16 Dec 2010
TL;DR: In this paper, les donnees de la litterature suggerent que l’injection of glucocorticoides dans lhippocampe dorsal serait l'une des causes possibles du developpement de troubles mnesiques de type ESPT.
Abstract: Une memoire emotionnelle normale se base sur la selection de stimuli predictifs d’un evenement important pour l’individu. Cependant, ce processus de selection peut etre compromis en situation de forte intensite emotionnelle. En particulier, la selection d’un element saillant non necessairement predictif, associee a une amnesie de type declaratif pour les elements contextuels, caracterise les alterations mnesiques de l’etat de stress post-traumatique (ESPT). Les donnees de la litterature suggerent que l’action de glucocorticoides dans l’hippocampe serait l’une des causes possibles du developpement de troubles mnesiques de type ESPT. Nos travaux ont porte sur les conditions dans lesquelles les glucocorticoides dans l’hippocampe peuvent alterer les fonctions mnesiques chez la souris.En utilisant des procedures de conditionnement classique aversif, nous montrons que l’injection post-apprentissage de corticosterone dans l’hippocampe dorsal, en situation de forte intensite emotionnelle, conduit (1) a une selection incorrecte du stimulus saillant non predictif du choc electrique au detriment des elements contextuels (2) et a des dysfonctionnements d’activite neuronale au sein du circuit hippocampo-amygdalien (expression de c-Fos). De facon interessante, par une action sur le meme type de recepteurs (aux glucocorticoides, GR), l’injection de corticosterone dans l’hippocampe ventral conduit egalement a un processus incorrect de selection du stimulus predictif mais en faveur des elements contextuels. Enfin, un apprentissage en labyrinthe radiaire revele que l’injection de corticosterone dans l’hippocampe dorsal altere specifiquement la memoire relationnelle, analogue de la memoire declarative humaine, uniquement chez les animaux ayant ete au prealable exposes a un stress.L’ensemble de nos donnees revelent qu’un exces de glucocorticoides dans l’hippocampe contribue (1) a des deficits de memoires emotionnelle et relationnelle, (2) a la selection inadaptee de stimuli non predictifs d’un evenement aversif (3) reposant sur des dysfonctionnements du circuit hippocampo-amygdalien, le tout, correspondant a des alterations mnesiques de type ESPT.
References
More filters
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)....

    [...]