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A stimulus whose termination increases the frequency of the performance is called an aversive stimulus. Such an increase in frequency is called negative reinforcement. An aversive stimulus which increases the frequency of a performance by terminating it is called a negative reinforcer. An aversive stimulus such as an electric shock or a loud noise may influence behavior in different ways, depending on its relation to the animal's performance. It may decrease the frequency of, the performance it follows (punishment), it may elicit reflexes (unconditioned stimulus), or it may alter the frequency of many operant performances in the ongoing repertoire (emotion or anxiety).
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The kind of stimulus we commonly call unpleasant or painful. Technically, any stimulus whose presentation decreases the probability of responding or whose removal is reinforcing. Sometimes called punisher or negative reinforcer.
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A stimulus effective as a negative reinforcer or as a punisher, or that suppresses positively reinforced operant behavior during another stimulus that precedes it (cf PREAVERSIVE STIMULUS). A stimulus with any one of these effects is likely also to have the others, but it is not guaranteed to do so. Cf. NOXIOUS STIMULUS, PUNISHMENT, REINFORCEMENT.
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A stimulus, the removal of which is reinforcing, or which may produce a low rate in the presence of a stimulus which frequently precedes it (which thus becomes a conditioned aversive stimulus).
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is any behavior that prevents a negative reinforcer from occurring
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See negative reinforcement.
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The prevention of an aversive stimulus by a response. In deletion procedures, the response cancels presentations of the aversive stimulus; in postponement procedures, the response only delays presentations. In discriminated, discrete-trials, or signaled avoidance, an exteroceptive stimulus (sometimes called a wariii?ig stimulus) precedes the aversive stimulus; a response during this stimulus prevents the aversive stimulus on that trial. If no response occurs and the aversive stimulus is presented, escape from it typically depends on the same response that is effective for avoidance. In cotitinzious, free-opera?tt, or Sidman avoidance, no exteroceptive stimulus is arranged and, typically, there is no provision for escape. Each response postpones the aversive stimulus (usually, brief shock) for a fixed period called the response-shock (RS) interval; in the absence of responses, shocks are delivered regularly according to a shock-shock (SS) interval. Cf. NEGATIVE REINFORCEMENT.
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Avoidance describes a performance which increases in frequency because it postpones the appearance of an aversive stimulus. In the classical laboratory experiment, a rat postpones an electric shock for a brief interval each time it presses the lever. If the rat presses the lever frequently enough, .it avoids the electric shock. Avoidance is to be contrasted with escape, when the performance actually terminates the aversive stimulus.
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Behavior which reduces or eliminates stimuli which in the past have been followed by punishment. The punishment then, does not occur. Avoidance is different from escape we get out of punishment that has already started. For example, we avoid a traffic jam by taking an alternate route before we get in the jam, whereas we escape from a traffic jam by taking an alternate route after we have already gotten caught in the jam.
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A case of negative reinforcement in which the behavior increases in rate when it postpones or avoids completely an aversive stimulus. (Avoidance does not remove that aversive stimulus, because it has not yet occurred.) Nontechnically. Staying away from or doing something to keep from getting punished.

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