William R. Sewell

The treatment of reluctant speech using contingency management procedures

Abstract Two cases of reluctant speech were successfully treated using contingency management procedures in the school, home, and clinic. In both cases, the frequency of speech in particular environmental situations was increased to approximately normal levels. One year follow-up assessments revealed that these behavioral changes had been maintained. The results of these two case studies are discussed in terms of the therapeutic usefulness of differentiating between cases of reluctant speech and elective mutism.

Modification of an Antagonistic Social Behavior using Positive Reinforcement for other Behavior

Socially inappropriate target behaviors were decelerated by omission training through differential reinforcement of other behavior. For 4 male retardates omission training, reduced the maladaptive behaviors by 80%. The range of behavior during a 3-day probe was higher than and did not overlap the range during omission training. When omission was reintroduced, behavior was reduced to the level of the previous omission training. The results demonstrate that a positive contingency in isolation, omission training, as opposed to omission training used in conjunction with timeout, will decrease antagonistic behavir.

The behavioral treatment of elective mutism: Two case studies

Abstract Two electively mute children were successfully treated using a variety of behavior therapy techniques, including two procedures which have never been applied to the treatment of elective mutism, i.e. reinforcement sampling and an escape procedure. The frequency of speaking in particular environments, e.g. at school, was increased for both cases. Follow-up information, gathered from one month to one year after treatment, was obtained. In all cases, the behavioral changes had been maintained or improved.

The use of self-efficacy scaling in training student clinicians: Implications for working with stutterers

Abstract A scaling technique developed by Bandura for determining an individuals personal performance expectations (self efficacy) was applied to student clinicians working with stutterers. The self-efficacy scores of clinicians conducting treatment increased significantly while the scores of clinicians without treatment experience showed no significant change. As the student clinicians gained clinical experience there appeared to be a corresponding reduction in fear and avoidance of the treatment situation. Clinician fear concerning stuttering treatment appeared to have little relation to performance in treatment as rated by supervisors. The results indicate that self-efficacy scaling may be used to indicate clinician avoidance of working with stuttering clients.

The Detection of Inhibition Using the Resistance to Reinforcement Method

Pigeons learned to discriminate between a stimulus which signalled a variable-interval (VI) schedule of reinforcement and a stimulus which signalled extinction. In Experiment 1, for one group of four pigeons, a line- tilt stimulus was associated with extinction, and for another group of four pigeons this stimulus was uncorrelated with the availability of reinforcement. During a resistance to reinforcement phase, responses to this line-tilt stimulus and to a novel stimulus were reinforced on a VI schedule. Statistical comparisons of the response rates to these test stimuli indicated that subjects consistently responded at a higher rate to the line-tilt stimulus than to the novel stimulus. Between-groups comparisons of response rates to the line-tilt stimulus indicated no reliable differences. These results indicated that a novel stimulus had strong response suppression or inhibition effects when compared to stimuli to which the subjects had had previous exposure. However, stimuli which were correlated or uncorrelated with the availability of reinforcement were equivalent in their inhibitory or response suppression effects.Experiment 2 used a within-subject design to replicate and extend the findings of Experiment 1. The data from Experiment 2 also indicated that a novel stimulus was a very strong suppressor of responding. However, these data also indicated that a stimulus that had signalled extinction was a stronger inhibitor of responding than a stimulus that had been uncorrelated with reinforcement. These findings are discussed in terms of the stimulus- reinforcer and response-reinforcer contingency arrangements which produce inhibitory stimulus control. Methodological considerations for the detection of inhibition are also discussed.

VARIOUS COMBINATIONS OF TRADITIONAL INSTRUCTION AND PERSONALIZED INSTRUCTION

One hundred fifty-six students enrolled in an undergraduate learning course were instructed by one of six instructional methods which combined personalized instruction with techniques which have been used in courses taught by traditional methods-lectures, discussion groups, midterm exams, and laboratory projects. A comparison of final exam scores showed that students taught by three instructional combinations, namely, readiness tests-lecture, lecture-midterm, and readiness test-midterm, scored significantly higher than did students instructed only by personalized instruction. The most effective instructional combination was readiness tests lecture, which produced significantly higher final exam scores than all other methods except lecture-midterm.

A Chained Adjusting Ratio Schedule

3 pigeons were exposed to a chained FI 2, adjusting ratio schedule in which the ratio was equal to the number of responses emitted in the preceding interval. When the correlation between the interval output and the following ratio was removed, interval rates declined. A descriptive analysis of sequential interval output suggested an explanation for these findings.

Effect of Length of Training on Stimulus Control Using a Low Density Reinforcement Schedule

The effect of duration of training on stimulus control was assessed in pigeons using an operant paradigm. As the amount of training increased from 11 to 22 to 44 days, stimulus control increased, but there was no difference between the 44-day trained and 88-day trained pigeons. The results are attributed to different numbers of reinforcers. The possibility of an interaction between number of reinforcers and stimulus exposure is discussed. Suggestions are made for future research to assess the relative contribution of these variables.

A portable, inexpensive, walkie-talkie-type “bug-in-the-ear”

An inexpensive portable “bug-in-the-ear” is described for use in behavior modification training and treatment. The apparatus consists of an inexpensive “walkie-talkie” and a miniature earphone and plug. The advantages of the system are discussed relative to more sophisticated, expensive, and less mobile sound systems.

Stimulus Control After Training with Fixed Interval and Variable Interval Schedules of Reinforcement

Rats received discrimination training where light-on was the S+ condition and light-off the S- condition. 2 Ss were trained with a fixed interval (FI) 30-sec. schedule with a limited hold of 5 sec. during S+, while 3 Ss were trained with a variable interval (VI) 30-sec. schedule during S+. Probe testing produced steeper generalization gradients for the FI trained Ss than for the VI trained Ss. Exp. 2 was conducted with 2 more VI Ss trained and tested in an identical manner to the FI Ss of Exp. 1. Gradients for the FI Ss of Exp. 1 were steeper than for those of the VI Ss of Exp. 2. Thus less stimulus control was exerted after training with VI than with FI schedules. The discriminative properties of reinforcement during the VI schedule competed with and thereby weakened S+ stimulus control. An alternate explanation in terms of changes in response patterns was discussed.