OVERCOMING AN AUTISTIC CHILD'S FAILURE TO ACQUIRE A TACT REPERTOIRE

A 6-year-old nonvocal autistic girl who had acquired over 30 signs as mands (requests), simple intraverbals (English-sign translations), and imitative responses repeatedly failed to acquire a tact (labeling) repertoire. It was speculated that the verbal stimulus “What is that?” blocked the establishment of stimulus control by nonverbal stimuli. When procedures to transfer stimulus control from verbal to nonverbal stimuli were implemented, the subject quickly learned to tact all 18 target stimuli.     

Effects of error and errorless discrimination acquisition on reversal learning

The effectiveness of trial-and-error, graded-choice, and verbal-instruction procedures on the acquisition and maintenance of a two-choice simultaneous color discrimination in an intradimensional double-reversal learning situation was studied using 18 first-grade children. After acquiring a red-green discrimination during one 70-trial session, the discriminative roles of the stimuli were reversed for 30 trials, followed by a second reversal for 30 trials. Children in the graded-choice and verbal-instruction groups acquired and maintained the discriminations with fewer errors than children who learned by trial and error. The importance of the results in terms of two-stage discrimination learning theories is pointed out and similarities between errorless learning and overtraining are discussed.     

Early and late introduction of probes and stimulus control acquisition in fading

College students learned to name Braille patterns presented visually using a fading procedure in which Braille patterns were superimposed on letter names after which letter names were attenuated. Measurement of acquisition was accomplished by presenting probes—consisting of the Braille stimuli only—throughout fading. Effects of probes upon acquisition were assessed by introducing probes early or late in fading. Fewer fading levels were needed for Braille elements to acquire control when probes were introduced early rather than late. When probes were introduced late, all subjects learned to name the Braille elements as the letters were being faded out. When probes were introduced early, however, most subjects learned to name the Braille elements as they were being faded in. Since virtually no errors occurred during compound-stimulus presentations, the probe procedure did not induce errors during acquisition. Quantitative analysis of probe data suggested that inclusion of probes enhanced the control acquired by the Braille elements during compound-stimulus presentations. The reported effects may have been due to differences in the relative frequency of reinforcement presented during compounds and probes.     

Prepositional phrases spoken and heard

The relation between verbal and nonverbal behavior with common syntactic properties was investigated, using retarded and nonretarded children. Reinforcement was contingent on either verbal or nonverbal responses whereas responses of the other repertoire had no experimental consequences. Changes sometimes occurred in the unreinforced (collateral) repertoire, but they were always changes in the stimulus control of pre-existing topographies. A contingency involving responses of one repertoire never instated new topographies in the collateral repertoire. This suggested that the problem of “cross-modality generalization” should be reformulated to distinguish explicitly between instating new topographies and changing the stimulus control of pre-existing topographies. The result confirmed Skinner's hypothesis about “the same response spoken and heard” and clarified some anomalies in previous studies.     

Attentional demands and recall of verbal and color information in action events

Two experiments addressed the influence of secondary task performance at encoding on recall of different features of subject-performed tasks (SPTs) involving objects (e.g., turn the wallet). In Experiment 1, memory for verbs and colors of objects was assessed, with object names serving as cues. In Experiment 2, object and color memory were assessed, with verbs serving as cues. Results from both experiments indicated a greater deterioration of memory performance under divided attention for verbal features than for colors. In addition, intention to remember did not affect performance for any feature in either experiment. The overall pattern of outcome is discussed relative to the view that encoding of verbal features of SPTs is more attention-demanding than encoding of physical task features, such as color.     

Setting events controlling social verbal exchanges between students with developmental delays

The peer social verbal exchanges (social conversational units) between four developmentally delayed students were studied as a function of setting events. A single conversational unit consisted of a verbal exchange in which each individual functioned as both speaker and listener. Each unit included a three term verbal contingency. Data were collected by trained observers viewing videotapes of 20-minute sessions in which running times were burned onto the videotape. Frequencies of social conversational units were measured under two conditions. Comparisons were made between sessions in which the teacher responded only when spoken to and sessions in which the teacher was absent using a combined reversal and multiple schedule design. Results showed that peer conversational units emerged at high rates when the teacher was absent and at low or nonexistent rates when the teacher responded only when spoken to in the living room setting. The setting and audience control for peer verbal exchanges were discussed as functions possibly of either a punishing audience, establishing operations, or response deprivation.     

The transfer of specific and general consequential functions through simple and conditional equivalence relations

The purpose of this study was to examine the transfer of consequential (reinforcement and punishment) functions through equivalence relations. In Experiment 1, 9 subjects acquired three three-member equivalence classes through matching-to-sample training using arbitrary visual forms. Comparison stimuli were then given conditioned reinforcement or punishment functions by pairing them with verbal feedback during a sorting task. For 8 of the 9 subjects, trained consequential functions transferred through their respective equivalence classes without additional training. In Experiment 2, transfer of function was initially tested before equivalence testing per se. Three of 4 subjects showed the transfer without a formal equivalence test. In Experiment 3, 3 subjects were given training that gave rise to six new three-member conditional equivalence classes. For 2 of the subjects, the same stimulus could have either a reinforcement or punishment function on the basis of contextual cues that defined its class membership. Experiment 4 assessed whether equivalence training had established general or specific consequential functions primarily by adding novel stimuli in the transfer test. Subjects treated even novel feedback stimuli in the transfer test as consequences, but the direction of consequential effects depended upon the transfer of specific consequential functions through equivalence relations.     

An elicitation method for multiple linear regression models

This paper describes a method of quantifying subjective opinion about a normal linear regression model. Opinion about the regression coefficients and experimental error is elicited and modeled by a multivariate probability distribution (a Bayesian conjugate prior distribution). The distribution model is richly parameterized and various assessment tasks are used to estimate its parameters. These tasks include the revision of opinion in the light of hypothetical data, the assessment of credible intervals, and a task commonly performed in cue-weighting experiments. A new assessment task is also introduced. In addition, implementation of the method in an interactive computer program is described and the method is illustrated with a practical example.     

Modality-general benefit of eye-closure on the retrieval of intentionally learned information

The beneficial effect of eye-closure during retrieval was demonstrated in many studies addressing eyewitness memory or memory of episodic events. Fewer studies examined the effect concerning the intentional learning of verbal information. Furthermore, the question of whether the eye-closure effect is modality-specific, boosting visual memory only, or modality-general, boosting also other forms of memory (e.g., auditory memory), is still open. These issues were addressed in the present study. Participants (N = 129) were asked to study aurally and visually presented lists of unrelated nouns (within-subjects). During free recall, participants either kept their eyes open or closed their eyes (between-subjects). Eye-closure resulted in better free recall than keeping the eyes open. Importantly, this effect emerged for both visually and aurally presented word lists, suggesting that the effect of closing the eyes is rather modality-general. The results are discussed with respect to limitations of previous studies and practical implications.