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Biomedical subjects

G S REYNOLDS

Publications and source records attributed to G S REYNOLDS.

16 recordsLinked to original sources
PubMed1965

DEVELOPMENT OF BEHAVIORAL COMPENSATION TO THE EFFECTS OF SCOPOLAMINE DURING FIXED-INTERVAL REINFORCEMENT.

Rats were injected with scopolamine before every daily session of water reinforcement on a fixed-interval (FI) schedule. Initially the drug decreased the rate of responding. Control injections of scopolamine following each session did not. Over 119 sessions, the typical FI performance developed more slowly in the animals drugged before the sessions. Their rates of responding increased from session to session, to a level slightly greater than that of the animals drugged after the sessions. Their rates did not increase. The effects of injections before the session were not duplicated by increasing the deprivation of animals drugged after the session.

Animals↗
PubMed1964

OPERANT EXTINCTION NEAR ZERO.

Extinction in the presence of each of two stimuli reduces the rate of pecking in the presence of each of them to zero or near zero. When, however, pecking a third stimulus is reinforced, responding is resumed under the other stimuli, and more responses are made to the stimulus least associated with extinction.

Animals↗
PubMed1964

ACCURATE AND RAPID RECONDITIONING OF SPACED RESPONDING.

The performance maintained by reinforcing responses only when they terminated interresponse times (IRTs) of 20 sec or greater (DRL schedule) was almost the same during the first session of reconditioning as before extinction. As few as two reinforcements accurately reinstated both the pre-extinction rate of responding and the function relating the duration of an IRT to its conditional probability of occurrence (IRTs/op).

Animals↗
PubMed1964

TEMPORALLY SPACED RESPONDING BY PIGEONS: DEVELOPMENT AND EFFECTS OF DEPRIVATION AND EXTINCTION.

In the first five or six sessions on a DRL 20-sec schedule of reinforcement there developed a stable performance characterized by a relatively constant conditional probability of occurrence (IRTs/op) of interresponse times (IRTs) of durations greater than 5 or 6 sec. Extinction and the level of deprivation changed both the overall rate of responding and the form of the function relating the duration of an IRT to its value of IRTs/op. The value of IRTs/op decreased more rapidly for short than for longer IRTs, resulting in the emergence of a finer discrimination of IRT duration.

Animals↗
PubMed1963

Some limitations on behavioral contrast and induction during successive discrimination.

A pigeon's rate of pecking on a red key, reinforced at a constant frequency, may be changed by increasing or decreasing the frequency of reinforcement of pecking on a successively presented green key. The changes in the rate of pecking on red, called interactions, are of two types: contrast, in which the changes in the rates of pecking on the two colors are in opposite directions; and, induction, in which the changes in the rates are in the same direction. In previous data, a change in the frequency of reinforcement associated with the green key produced a corresponding change in the rate of pecking the green key and an opposite change (contrast) in the rate of pecking on the red key. The present data suggest that the magnitude of contrast is very small if pecking on the red key is reinforced at a high enough frequency (about 40 reinforcements per hr in the present experiment). Also, given that interactions occur, induction rather than contrast may result from small changes in a low frequency of reinforcement associated with green.

Animals↗
PubMed1963

On some determinants of choice in pigeons.

A pigeon's pecking at each of two or three simultaneously available red keys was reinforced at different frequencies with a conditioned reinforcer, an orange key, on which 25 pecks resulted in a presentation of grain. Pecking was occasionally punished with a period of no reinforcement during which each key was dark. Both with two and with three keys, the relative frequency of pecking on a key was equal to the relative frequency of reinforcement obtained by pecks on that key. Also, the absolute frequency of pecking on each key was a linear function with zero intercept of the absolute frequency of reinforcement associated with that key. The slope of this function varied with the number of available keys; it was steeper with two than with three. The relative frequency of switching from any key (two successive pecks on different keys) approximated a linear function with zero intercept and slope slightly greater than 1.0 of the total relative frequency of reinforcement associated with the keys to which the bird could switch. However, the relative frequency of switching to a particular key often showed systematic irregularities. The invariance in these data is the equality between the relative frequency of pecks on one of two or three keys and the relative frequency of reinforcement associated with that key.

Animals↗
PubMed1962

Temporal discrimination in pigeons.

Pigeons trained to peck a lighted key were presented with a key that was alternately dark and lighted. The key was dark for intervals of from 3 to 30 seconds. Pecking of the lighted key was reinforced only after the shortest or, in a second experiment, the longest interval that the key was dark. The pigeons were able to discriminate the duration of the dark interval.

Animals↗
PubMed1962

A facilitative effect of punishment on unpunished behavior.

The key pecking of two pigeons was reinforced on a variable-interval schedule of reinforcement during the presentation of each of two stimuli. In various phases of the experiment, punishment followed every response emitted in the presence of one of the stimuli. In general, when the rate of punished responding changed during the presentation of one stimulus, the rate of unpunished responding during the other stimulus changed in the opposite direction. This sort of change in rate is an example of behavioral contrast. When punishment was introduced, the rate of punished responding decreased and the rate of unpunished responding increased as functions of shock intensity. When the rate of previously punished responding increased after the termination of the shock, the rate of the always unpunished responding decreased. When the procedure correlated with a red key was changed from variable-interval reinforcement and punishment for each response to extinction and no punishment, the rate of reinforced responding during presentations of a green key decreased and then increased while the rate of the previously punished responding during red first increased and then decreased during extinction.

Animals↗