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: Findings from studies on fear conditioning, a form of associative learning whose neural circuitry is relatively well understood, that may be particularly suited for addressing the question of changes in synaptic strength underlie learning and memory are discussed.
309 citations
Cites background from "Probability of shock in the presenc..."
...For instance, strong fear conditioning can be induced with only a few temporal pairings of the CS and US, but presentation of additional CSs (partial reinforcement) or USs (degraded contingency) decreases the strength of the CSeUS association (Rescorla, 1968; Singh and Banerji, 1986; Cain et al., 2005)....
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...…strong fear conditioning can be induced with only a few temporal pairings of the CS and US, but presentation of additional CSs (partial reinforcement) or USs (degraded contingency) decreases the strength of the CSeUS association (Rescorla, 1968; Singh and Banerji, 1986; Cain et al., 2005)....
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...Fear conditioning also depends strongly on CSeUS contingencydthe degree to which the CS predicts the occurrence of the US (Rescorla, 1968)....
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TL;DR: The literature relevant to incentive contrast effects is reviewed, with emphasis on the data published since the reviews by Black (1968) and Dunham (1968). Contrary to the evidence available for the earlier reviews, the current literature indicates that positive contrast is a reliable phenomenon as mentioned in this paper.
Abstract: The literature relevant to incentive contrast effects is reviewed, with emphasis on the data published since the reviews by Black (1968) and Dunham (1968). Contrary to the evidence available for the earlier reviews, the current literature indicates that positive contrast is a reliable phenomenon. Its occurrence is facilitated by use of a constant delay of reward, use of a long runway, or possibly by a shift while a negative contrast effect, resulting from a previous shift, is still present in the animals’ behavior. Positive contrast also occurs in consummatory behavior when sucrose or saccharin solutions are shifted. Conditions that are ineffective in producing positive contrast are reviewed, as are the effects of numerous variables on both successive and simultaneous contrast. In addition, positive and negative contrast effects resulting from shifts in delay or percentage of reward, contrast resulting from shifts in sucrose, saccharin, or ethanol solutions, contrast in choice behavior, and transsituational contrast are reviewed. The relationship of the data to several theoretical interpretations of contrast is also considered.
307 citations
TL;DR: The results of the two experiments suggest that the relative reinforcement of a response determines its rate, whereas the stimulus-reinforcement contingency (a Pavlovian contingency) determines its resistance to change.
Abstract: Two multiple-schedule experiments with pigeons examined the effect of adding food reinforcement from an alternative source on the resistance of the reinforced response (target response) to the decremental effects of satiation and extinction. In Experiment 1, key pecks were reinforced by food in two components according to variable-interval schedules and, in some conditions, food was delivered according to variable-time schedules in one of the components. The rate of key pecking in a component was negatively related to the proportion of reinforcers from the alternative (variable-time) source. Resistance to satiation and extinction, in contrast, was positively related to the overall rate of reinforcement in the component. Experiment 2 was conceptually similar except that the alternative reinforcers were contingent on a specific concurrent response. Again, the rate of the target response varied as a function of its relative reinforcement, but its resistance to satiation and extinction varied directly with the overall rate of reinforcement in the component stimulus regardless of its relative reinforcement. Together the results of the two experiments suggest that the relative reinforcement of a response (the operant contingency) determines its rate, whereas the stimulus-reinforcement contingency (a Pavlovian contingency) determines its resistance to change.
302 citations
TL;DR: The maintenance of observing can be reconciled with the traditional theory that the acquisition of reinforcing properties proceeds according to the same rules as those for Pavlovian conditioning if it is recognized that the subject is selective in what it observes and procures a greater than proportionate exposure to the stimulus associated with the more desirable outcome.
Abstract: When experimenters require their subjects to perform some readily recorded response to gain access to discriminative stimuli but do not permit this behavior to alter the schedule of reinforcement, the response is classified, by analogy, as an “observing” response Observing responses have been used not only to analyze discrimination learning but also to substantiate the concept of conditioned reinforcement and to measure the reinforcing effect of stimuli serving other behavioral functions A controversy, however, centers around the puzzling question of how observing can be sustained when the resulting stimuli are not associated with any increase in the frequency of primary reinforcement Two possible answers have been advanced: (a) that differential preparatory responses to these stimuli as conditional stimuli make both the receipt and the nonreceipt of unconditional stimuli more reinforcing; and (b) that information concerning biologically significant events is inherently reinforcing It appears, however, that the stimulus associated with the less desirable outcome is not reinforcing The maintenance of observing can be reconciled with the traditional theory that the acquisition of reinforcing properties proceeds according to the same rules as those for Pavlovian conditioning if it is recognized that the subject is selective in what it observes and procures a greater than proportionate exposure to the stimulus associated with the more desirable outcome As a result of this selection, the overall frequency of primary reinforcement increases in the presence of the observed stimuli and declines in the presence of the nondifferential stimuli that prevail when the subject is not observing
297 citations
TL;DR: By 18-20 months children are inclined to establish a mapping between word and object only when a speaker displays signs of referring to that object.
Abstract: The language children hear presents them with a multitude of co-occurrences between words and things in the world, and they must repeatedly determine which among these manifold co-occurrences is relevant. Social factors--such as cues regarding the speaker's referential intent--might serve as one guide to whether word-object covariation should be registered. In 2 studies, infants (15-20 months and 18-20 months in Studies 1 and 2, respectively) heard novel labels at a time when they were investigating a single novel object; in one case the label was uttered by a speaker seated within the infant's view and displaying concurrent attention to the novel toy (coupled condition), whereas in the other case the label emanated from a speaker seated out of the infant's view (decoupled condition). In both studies, subsequent comprehension questions indicated that infants of 18-20 months registered a stable link between label and object in the coupled conditions, but not in the decoupled condition, despite the fact that covariation between label and object was equivalent in the 2 conditions. Thus, by 18-20 months children are inclined to establish a mapping between word and object only when a speaker displays signs of referring to that object.
287 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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