Generalization of cross-modal stimulus equivalence classes: operant processes as components in human category formation.

This study employed a stimulus-class rating procedure to explore whether stimulus equivalence and stimulus generalization can combine to promote the formation of open-ended categories incorporating cross-modal stimuli. A pretest of simple auditory discrimination indicated that subjects (college students) could discriminate among a range of tones used in the main study. Before beginning the main study, 10 subjects learned to use a rating procedure for categorizing sets of stimuli as class consistent or class inconsistent. After completing conditional discrimination training with new stimuli (shapes and tones), the subjects demonstrated the formation of cross-modal equivalence classes. Subsequently, the class-inclusion rating procedure was reinstituted, this time with cross-modal sets of stimuli drawn from the equivalence classes. On some occasions, the tones of the equivalence classes were replaced by novel tones. The probability that these novel sets would be rated as class consistent was generally a function of the auditory distance between the novel tone and the tone that was explicitly included in the equivalence class. These data extend prior work on generalization of equivalence classes, and support the role of operant processes in human category formation.     

TIME DELAY: A TECHNIQUE TO INCREASE LANGUAGE USE AND FACILITATE GENERALIZATION IN RETARDED CHILDREN

Institutional breakfast-serving procedures were manipulated to assess what effect changes in that aspect of the environment would have on requests for food. During baseline, six severely retarded children were required to pick up their food trays and return to their seats. The first manipulation, delaying the giving of the food tray for 15 seconds, served as a cue to evoke meal requests by three of the six children. Two of the remaining three required a model of an appropriate meal request (i.e., “Tray, please.”) at the end of the 15-second delay before they began requesting their meals. To evoke meal requests from the sixth child, an intensive training procedure, consisting of massed trials of delay and modeling, was required. Three different probes were administered to assess generalization across the people serving the meals, across mealtimes, and across both people and mealtimes. Typically, generalized responding in these new situations could be prompted by use of the 15-second delay procedure. Functional aspects of the delay procedure and its potential usefulness for evoking speech and facilitating generalization are discussed.     

Stimulus properties of conspecific behavior

Two experiments identified the conditions in which the behavior of one bird acquired discriminative control of the behavior of a second bird. The schedule-controlled behaviors of the “stimulus” bird were differentially correlated with the components of a multiple schedule according to which the pecking of an “experimental” bird produced food. In Experiment 1, three pairs of pigeons acquired a successive discrimination and two reversals with the conspecific stimuli. Experiment 2 included a control condition in which no systematic relationship existed between the conspecific stimuli and the component schedules. While differential responding during the components of the multiple schedule was again found when the conspecific stimuli were available, differential responding did not occur in the control condition. Test conditions included in the experiments indicated that (a) the differential responding was not dependent on the discriminative properties of reinforcement, (b) the pecking of the stimulus and experimental birds was temporally interrelated, (c) the visual conspecific stimuli were critical to the maintenance of the discrimination, and (d) the observed stimulus control immediately generalized to an unfamiliar conspecific.     

Stimulus generalization along a dimension based on a verbal concept

The present study examined generalization along a dimension based on a verbal concept of occupational status. The status dimension was scaled by students who placed occupation names into five status categories, Category 1 representing highest status and Category 5 the lowest status. In two experiments, key presses by students were occasionally reinforced when a slide showing an occupation name from Status Category 3 was present. For half the subjects, key presses were not reinforced during a name from Category 1; for the other half, presses were not reinforced during a name from Category 5. Occupation names from all status categories were later singly presented. In this generalization test, subjects typically divided the dimension into two parts, responding alike to all names within each part. The results suggest that generalization along a dimension in humans is mediated by a subject's verbal classifications of stimuli.     

A CLASSIFICATION SCHEME OF SOCIAL CONDITIONS OF REINFORCEMENT WITHIN GROUP OPERANT SYSTEMS1

Many different reinforcement contingencies are found in group operant systems, such as token economies and point systems. Some systems use group contingencies in which the reinforcement of any one participant may depend on the behavior of some other group member. Other programs are individual, in that participants earn reinforcers dependent only on their own behavior. The various possible arrangements of people and their response requirements are labelled “social conditions of reinforcement” in this paper. Previous attempts at classification have failed to categorize the variety of social conditions of reinforcement. In addition, some conditions that may produce behaviorally different effects have not been separated. The present paper classifies the social conditions of reinforcement found in applied programs in a three-dimensional scheme. The efficacy of the three major dimensions—reinforcing agent, recipient response requirement, and group response requirement—is supported by clinical and research data. The reinforcing agent dimension refers to the person(s) who dispenses reinforcers to group members. This major dimension is further subdivided: one or several agents may be either designated or nondesignated. Recipients are the group members who receive reinforcement. This dimension is also subdivided: one or several recipients in a social condition of reinforcement may obtain reinforcers either contingently or noncontingently. The group response requirement is a criterion that must be satisfied before any group participant is eligible for reinforcement. Some systems have no group requirement, and others have a group requirement that must be met by some designated or nondesignated participant(s). Supportive references and examples are given in the explanation of each dimension and subdimension. The behavioral impact of the various categories is emphasized. For all major dimensions, applied implications and research suggestions are discussed. Concluding remarks center on the utility of the present scheme, the classification of operant procedures other than positive reinforcement, and both theoretical and applied issues requiring further study (e.g., the long-term effects of participation in group contingencies).     

TEACHING RETARDED WOMEN A CLOTHING SELECTION SKILL USING COMMUNITY NORMS

Five institutionalized retarded women were taught a clothing selection skill to coincide with popular fashion. Normative data concerning popular styles of color-coordinated clothing were collected through observations of women's apparel in a local community. Using a puzzle simulation of a woman with alternative pieces of colored clothing, color coordination training was conducted using modelling, instructions, practice, praise, and feedback to teach popular selections of color combinations. A generalization training component with actual clothing was also included. Training was accompanied by large increases in percentage of popular color selections with the puzzle and actual clothing. The increases maintained over a seven- to 14-week followup period. Time efficiency measures supported the use of the simulation procedure as opposed to total reliance on actual clothing. The results underscore the utility of local norms in community preparation programs and the efficacy of instructional procedures for severely and profoundly retarded persons as part of their participation in the deinstitutionalization movement.     

Construction of equal-hue discriminability scales for the pigeon.

Equal-hue discriminability steps for the pigeon are shown as tabular entries that can be summed or interpolated to produce sequences of equal discriminability steps of various step size. Equal-hue discriminability sequences can be constructed where the number of stimuli and spectral range are specified, or where an interval in one spectral region is to be equated to an interval in another spectral region.     

Measuring nominal scale agreement between a judge and a known standard

Two designs for comparing a judge's ratings with a known standard are presented and compared. Design A pertains to the situation where the judge is asked to categorize each ofN subjects into one ofr (known) classes with no knowledge of the actual number in each class. Design B is employed when the judge is given the actual number in each class and is asked to categorize the individuals subject to these constraints. The probability distribution of the total number of correct choices is developed in each case. A power comparison of the two procedures is undertaken.     

Effect of the good behavior game on disruptive library behavior

A modification of the good behavior game was used to reduce disruptive behaviors during a weekly library period of children in a fourth-grade class. Modifications included student input in designing rules, attempts to state rules in positive terms, observation of class behavior in the experimental (library) setting as well as in a comparison (classroom) setting, and librarian involvement in instituting the game coupled with teacher involvement in delivering reinforcers. Reinforcers consisted of special classroom activities conducted by the teacher with winning team members. Modification of the good behavior game did not detract from its effectiveness in reducing disruptive and off-task behavior.     

ASSESSMENT AND TREATMENT OF CLINICAL FEARS IN MENTALLY RETARDED CHILDREN

Three moderately mentally retarded females ranging from 8 to 10 years of age were treated for long-standing fears. These children had refused to talk with or be in the same general vicinity of adults other than their parents, a few close family members, and to a lesser degree, their teacher. To establish an accurate criterion for successful performance on dependent measures, participants were matched on age, sex, and level of mental retardation with children having “normal” amounts of fear. Dependent measures included approaching and talking to strange adults as well as child ratings of overall fear. Participant modeling was given by the mother who provided a sufficient amount of physical and verbal prompts to ensure that an acceptable greeting of adults specified by the mother were made. These prompts were gradually faded out as treatment progressed. Treatment, which was given in a multiple baseline format across subjects, proved effective and gains in the reduction of fears were maintained at the six month follow-up.