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Biomedical subjects

C B Ferster

Publications and source records attributed to C B Ferster.

13 recordsLinked to original sources

Autoshaped key pecking maintained by access to a social space.

When four experimentally naive pigeons were exposed to occasional forward pairings of a keylight followed by a doorlight (that signaled access to a large social space), all subjects began to peck the lit key. In a second experiment, where the keylight either preceded the presentation of the doorlight or was presented independently of it, key pecking was maintained only in the former circumstance. The unconditioned stimulus in these experiments--arrival in the social space--did not elicit pecking. Hence, the conditioned response of key pecking and the unconditioned response of entering the social space differed. This demonstration of autoshaping with a social-space unconditioned stimulus argues against a stimulus-substitution account of the findings.

Animals↗

The contribution of an added counter to a fixed-ratio schedule.

Although previous research showed that a visual counter increased the rate of responding on a large fixed-ratio schedule, a theoretical analysis of the factors responsible for fixed-ratio performance suggests that the primary control by number of responses since reinforcement is to weaken the performance. The present experiment employed a multiple schedule in which the same fixed-ratio value alternated with and without an added counter. It tested the hypothesis that the differential reinforcement of high-rate responding masked the attenuation of the fixed-ratio performance from the unoptimal discriminative control produced by the fixed relation between number of responses and reinforcement. In the present experiment the postreinforcement pause was consistently longer in the components with the added counter, while running rates remained comparable between the components of the multiple schedule. Both components of the multiple schedule involved differential reinforcement of high-rate responding while only the components with the added counter amplified the discriminative control by number of pecks since reinforcement.

Journal Article↗

An experimental space combining individual and social performances.

This report describes several primate environments in which two or more animals shared a common social area. Automatic programming was used to permit concurrent individual sessions. Some of the behavioral phenomena observed in these environments, including reinforcing properties of social interactions, are discussed.

Aggression↗