Discrimination stimulus preexposure and learning of an operant discrimination in the rat.

Mellgren, Roger L.; Ost, John W.P.

doi:10.1037/h0031663

Cited by 21 publications

(12 citation statements)

References 11 publications

(8 reference statements)

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“…Preexposure to a stimulus makes that stimulus less effective as a CS in classical conditioning procedures and in variations of the Estes-Skinner procedure (see Lubow, 1973, for a review). Similar effects of retardation have been found in instrumental discriminations following preexposure to the positive and negative discriminative stimuli (Halgren, 1974;Mellgren & Ost, 1971). The reversed discrimination animals of the second experiment gave the same results as the reversed discrimination animals of the first experiment; that is, the nonreinforced response increased in probability for 5 to 10 sessions.…”

Section: Animalsupporting

confidence: 67%

The Control of Responding by Sounds: Unusual Effect of Reinforcement

1979

J Exper Analysis Behavior

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Naive rats were trained to respond on one lever in the presence of noise bursts from one speaker and on a second lever in the presence of noise bursts from a second speaker. The speakers were mounted behind the levers. When responding on the lever adjacent to the sounding speaker was reinforced, control developed within fewer than five trials. When responding on the nonadjacent lever was selectively reinforced, responding on the lever adjacent to the sounding speaker increased in probability for several sessions. Naive rats were trained to respond on the nonadjacent lever following preexposure to the sound. Responding on the lever adjacent to the sounding speaker increased in probability, showing that novelty was not responsible for the effect. Naive rats were run on automaintenance procedures in which there was no explicit pairing of sound and magazine operation, 100% pairing of sound and magazine operation, or magazine operation following 40% of sound presentations. None of the rats acquired the response of approaching and sniffing the sounding speaker, indicating that sound-magazine pairing was not responsible for the effect.Key words: auditory discrimination, lever press, reinforcement, ratsMammals have evolved a number of specific abilities which enable them to acquire certain auditory discriminations readily. For example, the ability of rats and monkeys readily to discriminate the position of sounds is a function of the complexity of the spectral content of the sound (Beecher & Harrison, 1971;Brown, Beecher, Moody, & Stebbins, 1975;Harrison & Beecher, 1969;Harrison & Briggs, 1977), and of the relative positions of the sound source and response sites (Downey & Harrison, 1972Harrison, Downey, Segal, & Howe, 1971;Harrison, Iversen, & Pratt, 1977). White noise is more salient than a pure tone (Segal & Harrison, 1978), and hedgehogs, in contrast to cats and tree shrews, cannot discriminate the position of a pure tone below about 15 kHz, although such sounds are well within their range of hearing (Masterton, Thompson, Bechtold, & Robards, 1975 tory discrimination. The general approach to the problem is to find an auditory discrimination which is rapidly acquired (suggestive of specialization) and then to analyse the discrimination with respect to possible specializations which are responsible for the rapid acquisition. The discrimination of the position of sounds of complex spectral content is acquired within one or two trials (Beecher & Harrison, 1971) and is thus suitable for investigation of the special processes underlying the rapid acquisition. Rapid acquisition may depend on a special effect of reinforcement upon the response of approaching the sound source. When an animal behaviorally interacts with a sound source under natural conditions, the source must necessarily be approached. The ubiquity of the need for this approach response over the evolutionary history of the animal may be reflected in the behavioral effect of reinforcing a response in the presence of the sound. Briefly, whatever response is dif...

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Section: Animalsupporting

confidence: 67%

The Control of Responding by Sounds: Unusual Effect of Reinforcement

1979

J Exper Analysis Behavior

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“…In experiments in which rats were exposed to an auditory stimulus paired with shock, preexposure reduced its effectiveness as a conditioned stimulus (Carlton & Vogel, 1967;Crowell & Anderson, 1972;Hall & Pearce, 1979;Lubow, Schnur, & Rifkin, 1976;Rescorla, 1971). Equivalent effects using food-based behavior have been reported by Harrison (1979), Halgren (1974), and Mellgren and Ost (1971).…”

Section: Stimulus Noveltymentioning

confidence: 92%

Auditory Discrimination: The Konorski Quality‐location Effect

Neill

Harrison

1987

J Exper Analysis Behavior

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Konorski showed that when a go/no-go procedure was used, sound quality discriminations were rapidly acquired and sound location discriminations were slowly acquired. These findings have been interpreted as a general constraint on the acquisition of auditory discriminations (quality-location effect). However, experiments carried out within an evolutionary framework (Harrison, 1984) have shown that the rate of acquisition of sound location discriminations varies widely as a function of the inclusion or exclusion of naturalistic features. These data suggest that Konorski's findings were a function of the special conditions of the experiments. The first purpose of the present experiments was to assess whether rats showed the effects noted by Konorski when studied under similar conditions. The second purpose was to study the effect of manipulating two natural features (novelty and stimulusresponse adjacency) to assess whether the acquisition rates of quality and location discriminations could be greatly modified or made approximately equal, or both. When a go/no-go procedure was used and the other conditions were similar to those of Konorski, rats acquired a quality discrimination but did not acquire a location discrimination. However, when the S+ or S-were presented through a closely adjacent speaker, the sound location discrimination was acquired as rapidly as the quality discrimination. Finally, preexposing the animal to either S+ or S-retarded the rate of or prevented the acquisition of the quality discrimination. The experiments showed that the quality-location effect was determined primarily by the conditions used in Konorski's experiments, and that the effect is not a general constraint on learning.Key words: auditory discrimination, go/no-go procedure, quality-location effect, constraints on conditioning, Konorski, location discrimination, rats In a classical series of studies on auditory discrimination, Konorski and his colleagues showed that when a go/no-go procedure is used, auditory quality discriminations (e.g., metronome vs. buzzer, 300 Hz vs. 1,500 Hz tones) were more readily acquired than were discriminations of sound source location. When a go-left/go-right procedure was used, however, location discriminations were more readily acquired than were stimulus quality discrim-

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“…Recent investigation has shown that active learning does indeed occur when conditioned stimuli (CSs) and unconditioned stimuli (USs) are independently presented. Mellgren and Ost (1971) reported that a group for which CSs were presented independently of food took longer to learn later that the CSs were associated with the food than did naive rats (or even rats for whom the CSs predicted the opposite relationship with food). Kemler and Shepp (1971) showed that irrelevant stimuli were most slowly learned about when they became the relevant stimuli for the solution of a discrimination problem for children.…”

Section: Cognitive Deficitsmentioning

confidence: 99%

Learned helplessness: Theory and evidence.

Maier

Seligman²

1976

Journal of Experimental Psychology: General

2,054

1,186

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In 1967, Overmier and Seligman found that dogs exposed to inescapable and unavoidable electric shocks in one situation later failed to learn to escape shock in a different situation where escape was possible. Shortly thereafter Seligman and Maier (1967) demonstrated that this effect was caused by the uncontrollability of the original shocks. In this article we review the effects of exposing organisms to aversive events which they cannot control, and we review the explanations which have been offered.There seem to be motivational, cognitive, and emotional effects of uncontrollability. (a) Motivation. Dogs that have been exposed to inescapable shocks do not subsequently initiate escape response in the presence of shock. We review parallel phenomena in cats, fish, rats, and man. Of particular interest is the discussion of learned helplessness in rats and man. Rats are of interest because learned helplessness has been difficult to demonstrate in rats. However, we show that inescapably shocked rats do fail to learn to escape if the escape task is reasonably difficult. With regard to man, we review a variety of studies using inescapable noise and unsolvable problems as agents which produce learned helplessness effects on both instrumental and cognitive tasks, (b) Cognition. We argue that exposure to uncontrollable events interferes with the organism's tendency to perceive contingent relationships between its behavior and outcomes. Here we review a variety of studies showing such a cognitive set. (c) Emotion. We review a variety of experiments which show that uncontrollable aversive events produce greater emotional disruption than do controllable aversive events.We have proposed an explanation for these effects, which we call the learned helplessness hypothesis. It argues that when events are uncontrollable the organism learns that its behavior and outcomes are independent, and that this learning produces the motivational, cognitive, and emotional effects of uncontrollability. We describe the learned helplessness hypothesis and research which supports it.Finally, we describe and discuss in detail alternative hypotheses which have been offered as accounts of the learned helplessness effect. One set of hypotheses argues that organisms learn motor responses during exposure to uncontrollable shock that compete with the response required in the test task. Another explanation holds that uncontrollable shock is a severe stressor and depletes a neurochemical necessary for the mediation of movement. We examine the logical structure of these explanations and present a variety of evidence which bears on them directly.

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Discrimination stimulus preexposure and learning of an operant discrimination in the rat.

Cited by 21 publications

References 11 publications

The Control of Responding by Sounds: Unusual Effect of Reinforcement

The Control of Responding by Sounds: Unusual Effect of Reinforcement

Auditory Discrimination: The Konorski Quality‐location Effect

Learned helplessness: Theory and evidence.

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