Sign language is an effective form of alternative communication for persons with autism and other developmental disabilities. Only a few studies have systematically measured the effects of sign language on the vocal responses of its users. This study employed a multiple baseline design to evaluate the effects of sign language on the vocal responses of a four-year-old boy with autism. Results indicate that a reinforcement contingency placed only on sign responses is inadequate for maintaining vocal responses. When a reinforcement contingency is placed on sign responses as well as vocal responses that the user is capable of emitting in verbal imitation, both sign and vocal responses are maintained. Results are discussed in terms of the need for a reinforcement contingency placed on vocal and sign responses, the effects of teaching procedures on response variability, and the need for future research to examine procedures utilized to teach sign language to persons within the developmental disabilities population.

The purpose of this study was to examine the relation between stimulus equivalence (briefly, networks of relations among stimuli) and the extension of stimulus function (briefly, spread of effect across network) more closely than has been possible before. The traditional view of this relation suggests that equivalence classes mediate the extension of stimulus function and are, therefore, necessary for any extension to occur. This study used a preparation in which the conditional discriminations required for the development of equivalence classes and the simple discriminations required for the extension of function were trained or tested simultaneously. Results suggest that equivalence are not necessary for the extension of stimulus function though they may be sufficient.

Previous research has shown that variability is a reinforceable dimension of operant behavior. Additionally, it has been demonstrated that learning is facilitated when variability in responding is high. In this research, variability was observed within an operant composed of any sequence of six left and right key presses. Variability was either a requirement for point delivery (VAR conditions) or points were delivered independent of variability (ANY conditions). Two groups of college undergraduates experienced different orders of conditions. One group began the experiment under VAR conditions, and the variability requirement was later removed. The other group began the experiment under ANY conditions, and the variability requirement was later added. A concurrently reinforced target sequence (i.e., an always-reinforced sequence of left and right key presses) was introduced to both groups after these orders of conditions had been experienced. A variety of outcomes resulted. Subjects learned the target sequence when variability was both high and low with non-target points concurrently available. Other subjects learned the target sequence after all non-target point deliveries had been suspended. One subject failed to acquire the target sequence at all. These results were compared to previous findings and possible explanations for the discrepancies were suggested.

This study sought to assess the effects of pairing a neutral stimulus with a reprimand contingent on occurrences of two topographies of problem behavior. Using a multiple baseline withdrawal with a nested multi-element design, contingencies were first applied to eye poking and, subsequently, to a second behavior, skin picking. In each case, the participant wore wristbands (a previously neutral stimulus) during treatment sessions. Results indicated that the reprimands were effective in decreasing both behaviors. In addition, when skin picking resulted in reprimands, eye poking also decreased. However, when reprimands were contingent on eye-poking, the effects did not appear to generalize to skin-picking. Some possible accounts for this asymmetrical pattern of generalization are discussed.

This study investigated the effects of a precision teaching package on response rates of children with autism. Prior to both experiments a preference assessment was conducted to identify high preference activities for each participant. Experiment 1 investigated whether response rates would shift as a function of rate-contingent consequences during an academic task. Different activities were associated with different rates of responding. The experimental package of 1 minute timings, rate contingent consequences, and charting was successful in increasing the rates of responding when the most highly preferred activity was associated with high rates of responding. When the contingencies were switched and the most highly preferred activity was contingent on lower rates of responding, the participant's responding did not decrease. Experiment 2 was an attempt to replicate the results of Experiment 1 using a multiple baseline across tasks. The experimental package was not successful in increasing the rate of responding.

Skinner (1957) suggested that verbal responses learned as mands are not necessarily emitted in tact relations and vice versa. Previous empirical research has found that newly acquired mands and tacts can be functionally independent. The present study investigated 1) whether novel responses taught in mand relations would be emitted as tacts when opportunity for tacting was presented; 2) whether novel responses taught in tact relations would be emitted as mands when opportunity for manding was presented; and 3) whether the size of pre-experimental mand and tact repertoires affected the rate of acquisition and/or transfer. Two vocal-verbal children with autism were taught three novel responses as mands and three other responses as tacts. Mand topographies transferred to tact relations and tact topographies transferred to mand relations for both participants. Overall acquisition as well as transfer of mands and tacts was faster for the participant with an entering repertoire of approximately 175 mands and 175 tacts than for the participant with a repertoire of approximately 100 mands and 100 tacts.