Ernest G. Maples

Flexibility in the Species-typical Songs of Gibbons

Flexibility, or a capacity for situational variation, is an important characteristic of gibbon vocalization—one which may be seen as necessary to the functional effectiveness of species-typical songs. This paper reviews literature reporting flexibility of gibbon vocal behavior in relation to reinforcement contingencies, the singing of neighboring gibbons, development of pair coordination in the duet-singing of siamang gibbons, sequential progression in the elaboration of organizing sequences in siamang gibbons, and “repairs” of organizing and great-call sequences. A theoretical framework to account for the development of flexibility in species-typical behaviors is drawn on the basis ofGlickmans andSchiffs (1967) proposal of the reinforcing power of species-typical behaviors and associated feedback and consequent stimuli.

TAPED VOCALIZATION AS A REINFORCER OF VOCAL BEHAVIOR IN A SIAMANG GIBBON (SYMPHALANGUS SYNDACTYLUS)

The experiment demonstrated operant control of the vocal behavior of an adult male siamang by using taped vocalizations of wild siamangs as the reinforcer. The procedure consisted of 38 sessions divided into five phases. Baseline (three sessions): taped vocalizations were presented continuously until the subject made two vocal responses, then were terminated entirely. Operant 1 (five sessions): following elicitation of vocal behavior, taped vocalizations were presented contingently on any vocal response by the subject. Operant 2 (nine sessions): a 5-min. elicitation period preceded the onset of the contingency period. Discrimination-extinction (12 sessions): the 5-min. elicitation period was followed by an extinction period in which no taped answering calls were presented. Reconditioning (nine sessions): the procedure was identical to that for Operant 2. During all phases, the session continued until the subject ceased emitting vocal responses. Mean times spent calling for the last three sessions of each phase were: Baseline, 0.0 (min.); Operant 1, 1.60; Operant 2, 6.50; Discrimination-extinction, 3.56; and Reconditioning, 6.71. The results represent the operant control of a prepotent, species-typical pattern of behavior by use of a reinforcing stimulus that is specifically relevant to that behavior.

Taped Vocalization as a Reinforcer of Vocal Behavior in a Female Agile Gibbon (Hylobates Agilis)

The study demonstrated the effectiveness of tape-recorded answering calls as reinforcers of vocal behavior in a female agile gibbon. Following baseline, typical conditioning, extinction, and reconditioning effects were demonstrated. The findings support the proposition that many species-typical behaviors may act as reinforcers.

Stimulus Adaptation as an Alternative to Latent Learning

The experiment investigated the hypothesis that latent learning effects may be based on simple stimulus adaptation. Three groups of rats were reinforced for left-turning responses on an elevated T-maze. Prior to the onset of reinforcement, a latent-learning group was given a number of nonreinforced trials on the T-maze, and an adaptation group was given the same number of nonreinforced trials on the maze segments assembled as a runway. A regular learning group was given reinforcement from the outset. Both of the former groups showed a typical latent learning effect, reaching criterion in fewer reinforced trials than the regular learning group (Ps < .05). It was suggested that stimulus adaptation increases responsiveness to the reinforcer and thus promotes rapid learning. Such adaptation may be considered the basis of latent learning effects in most cases.

CONTIGUOUS WITHDRAWAL CONDITIONING: A MODEL FOR PUNISHMENT

The study was intended to extend Dennys elicitation theory, which accounts for reinforcement effects through contiguously conditioned approach responses, to the treatment of punishment. This treatment would rest on a demonstration of contiguously conditioned withdrawal responses to stimuli which have been paired with the onset of an aversive stimulus. Two groups of 20 male rats were trained in random order in a standard Skinner box. Experimental Ss received 25 trials in which the onset of a 6-w light was paired with the onset of a 1-ma. shock. Controls received 25 presentations of the light and shock, but these were presented uncorrected with one another. Ss were tested individually in a modified T-maze. A 6-w light was presented in one of the T-arms, randomly selected. Of 20 experimental Ss 17 withdrew from the light but only 9 of 20 control Ss withdrew. The difference between proportions was significant (p < .01). The findings are taken as allowing the extension of Dennys theory to account for punishment.

MATHEMATICAL ACHIEVEMENT OF THIRD- AND FOURTH-GRADE STUDENTS IN COMPENSATORY EDUCATION WHEN USING TWO TYPES OF CALCULATORS

An earlier study by the authors showed conventional handheld calculators to be generally superior to both programmed-feedback calculators and conventional instruction in promoting mathematical achievement in normally achieving third-grade students. The present study compared those same groups among third- and fourth-grade students in compensatory education. Measures of mathematical achievement were acquisition and retention of mathematical concepts, computation, and total achievement. Among fourth-grade compensatory students, hand-held calculators again proved to be superior on most measures of acquisition and retention. Among third-grade compensatory students, however, the programmed-feedback calculator produced generally superior retention of mathematical gains. Programmed-feedback calculators then seem to be beneficial with low-achieving students who have not yet acquired basic mathematical competencies.

Stimulus Adaptation and Latent Learning, Type III

10 rats given stimulus adaptation in unassembled maze components, then trained in the assembled maze, performed similarly to rats given typical Type III latent-learning experience. Both groups reached a learning criterion significantly faster than control subjects who were trained in the assembled maze from the outset. It was suggested that stimulus adaptation may account for many instances of latent learning.

Contiguous Approach Conditioning: A Model for Sidman Avoidance Learning:

The study sought to extend M. R. Dennys contiguous approach conditioning model of instrumental reinforcement effects to account for Sidman avoidance conditioning. Experimental subjects (rats) received a 15-sec. duration light which was paired, independently of the subjects behavior, with the nonoccurrence of regularly scheduled 1-ma. shocks. Controls received light and shock unpaired. All subjects were then tested in a simple T-maze for approach to the light. Groups did not differ significantly in the direction of their initial response (approach or nonapproach to the light) but did differ in latency of approach to the light. Further, a significantly higher proportion of experimental subjects than control subjects approached the light within the 15 sec. that had been the “safety” period during pairing. While these findings are largely consistent with Dennys theory, they might also be taken to support expectancy or informational interpretations of Sidman avoidance.

Deprivation as a Learning Variable: Effects of Maintenance Schedule and Current Deprivation

The study investigated two aspects of food deprivation—maintenance schedule and current deprivation—in their effects on both speed and accuracy measures of learning. Male rats were assigned to 3 groups. High-High Ss were maintained at 22 hr. deprivation and trained 22 hr. after food removal. High-Low Ss were maintained at 22 hr. deprivation and trained 6 hr. after food removal. Low-Low Ss were maintained at 6 hr. deprivation and trained 6 hr. after food removal. The apparatus was a four-choice-point elevated T-maze. Food was presented following the final correct choice on each trial. After 10 training trials, all Ss were shifted to a 14-hr. maintenance schedule and 10 days later were given a single test trial. On both speed and accuracy measures for both the last training trial and the post-shift test-trial, the performance of the Low-Low group was significantly inferior to that of the two High groups while those groups did not differ from one another.

Current Deprivation, Maintenance Schedule, and Reaction to Food

The study compared the effects of current deprivation (hours since feeding) and maintenance schedule (hours per day fed) on the responsiveness to food. The subjects were 30 Holtzman rats assigned to three groups. Response measures were latency-to-eat and amount eaten in 1 min. Only maintenance schedule was shown to be significant. This result is consistent with previously demonstrated effects of these variables on food reinforcement and with theoretical views of Sheffield, Denny, and Premack.