Precuing the Target Location in Visual Searching by a Chimpanzee (Pan troglodytes): Effects of Precue Validity

A chimpanzee ( Pan troglodytes ) performed a visual search task using a modified matching-to-sample procedure in which a sample stimulus was followed by the search display, which contained one stimulus identical to the sample (target) and several uniform stimuli different from the sample (distractors). On cued trials, while the subject was observing the sample, a white square (precue) appeared at the location where the target was to be presented (valid trials), or elsewhere (invalid trials). The validity of the precue (correspondence between the cued and the target locations) was changed from 0% to 100% across conditions. Cost-benefit analyses were performed on the difference between valid and noncued trials (benefit) and between invalid and noncued trials (cost). Under the high-validity conditions, the response times were shorter when the cued location corresponded to the target location than when the precue did not appear. When the cued location did not correspond to the target location, on the other hand, the subject took longer to select the target than on noncued trials. When the validity of the precue was relatively low, however, cost of the invalid trials disappeared, while benefit of the valid trials remained. These results confirmed the two-process (automatic and attentional) theory of priming in human information processing; the advance information had the same effects on a chimpanzee's visual search performance as on humans'.     

The effects of attentional shift training on the execution of soccer skills: A preliminary investigation

One of the most important skills in soccer is the ability to respond quickly and accurately to the changing demands of the competitive environment (i.e., position of ball, teammates, opponents). A multiple baseline design across 4 male collegiate soccer players was used to determine the effectiveness of an attentional training program on the execution of targeted soccer skills. The treatment included information and laboratory attentional shift exercises followed by practice of attentional shifting skills on the execution of different soccer exercises. Following treatment, the accuracy of execution of the experimental soccer drill improved.     

A PRELIMINARY COMPARISON OF REINFORCER ASSESSMENT METHODS FOR CHILDREN WITH ATTENTION DEFICIT HYPERACTIVITY DISORDER

We evaluated the relative treatment utility of a verbal forced-choice questionnaire, child nomination, and direct observation for identifying the most potent reinforcers for children with attention deficit hyperactivity disorder. Results demonstrated that all three methods were more likely to disagree than to agree, that a forced-choice format may enhance verbal reinforcer assessment, and that further development and evaluation of verbal reinforcer-assessment methods are needed.     

Stimulus control in the use of landmarks by pigeons in a touch-screen task

Pigeons were tested in a search task on the surface of a monitor on which their responses were registered by a touch-sensitive device. A graphic landmark array was presented consisting of a square outline (the frame) and a colored “landmark.” The unmarked goal, pecks at which produced reward, was located near the center of one edge of the frame, and the landmark was near it. The entire array was displaced without rotation on the monitor from trial to trial. On occasional no-reward tests, the following manipulations were made to the landmark array: (a) either the frame or the landmark was removed; (2) either one edge of the frame or the landmark was shifted; and (3) two landmarks were presented with or without the frame present. On these two-landmark tests, the frame, when present, defined which was the “correct” landmark. When the frame was absent, the “correct” landmark was arbitrarily determined. Results showed that pecks of 2 pigeons were controlled almost solely by the landmark, pecks of 3 were controlled primarily by the landmark but the frame could distinguish the correct landmark, and 1 bird's behavior was controlled primarily by the frame. Stimulus control in this search task is thus selective and differs across individuals. Comparisons to other search tasks and to other stimulus control experiments are made.     

THE TREATMENT OF COVERT SELF-INJURY THROUGH CONTINGENCIES ON RESPONSE PRODUCTS

Assessment and treatment of covert self-injurious behavior are complicated because it is difficult to quantify and apply differential consequences to covert responses. In this study, both tangible and social reinforcers were identified using reinforcer assessment methods. These reinforcers were then provided contingent upon the absence of tissue damage identified during physical examinations, resulting in near 100% success in physical assessment checks that was maintained over 10 months.     

Decomposing the encoding of action events: A dual conception

Two experiments are reported in which we tested the hypothesis that encoding of verbal features of subject-performed tasks or SPTs (e.g., bounce the ball, lift the spoon) is attention-demanding and effortful, whereas physical features of this memory task (e.g., color, weight) are acquired with little effort, and without deliberate encoding strategies. In Experiment 1, subjects were asked to perform a series of SPTs and were examined on recall of verbal instructions and colors of objects involved under conditions of focused or divided attention. In Experiment 2, performance of a series of SPTs was followed by recall of verbal instructions and recall of weights of objects involved. Results of both experiments indicated that recall of the verbal task component was negatively affected by requirements of dual-task performance, whereas recall of both physical task features was equally good in both encoding conditions. The obtained pattern of outcome is interpreted as supportive of the dual conception hypothesis of the nature of the encoding of action events.     

Analysis of the elements of attention: A neuropsychological approach

A model for conceptualizing the components or elements of attention is presented. The model substitutes for the diffuse and global concept of attention a group of four processes and links them to a putative system of cerebral structures. Data in support of the model are presented; they are derived from neuropsychological test scores obtained from two samples, the first consisting of 203 adult neuropsychiatric patients and normal control subjects, and the second, an epidemiologically-based sample of 435 elementary school children. Principal components analyses of test scores from these two populations yielded similar results: a set of independent elements of attention that are assayed by different tests. This work presents a heuristic for clinical research in which the measurement of attention is essential.     

RELATIVE EFFECTIVENESS OF TEACHER ATTENTION AND THE “GOOD BEHAVIOR GAME” IN MODIFYING DISRUPTIVE CLASSROOM BEHAVIOR1

A variety of behavioral procedures have been employed in recent years to modify disruptive classroom behavior. Such methods have been developed with the belief that curtailing disruptive behavior would strengthen positive classroom performance. In this study, two procedures, the good behavior game and the teacher-attention method, were compared to determine short-run effectiveness. Four teachers (two fourth-grade and two fifth-grade) implemented both methods in their classrooms over a five-week period. Presentation of methods was alternated in a counterbalanced design to control for order effects. Each of the four classrooms consisted of 25 students. A time-sampling procedure was used to record the presence or absence of disruptive behavior within 15-second intervals. Disruptive behavior was defined as any talking-out or out-of-seat behavior without permission. The results indicated that both procedures were effective in modifying disruptive classroom behavior, but that the good behavior game reduced disruptive behavior significantly better than the teacher-attention method. In addition, all teachers preferred the game to the teacher-attention procedure. This reaction seemed related to the effort involved in initiating the two activities. The good behavior game required less effort on the teacher's part. However, use of the game alone raises certain ethical considerations. One such issue involves abuse of peer pressure. Also, there is a possibility that negative rules may tend to promote resentment. Positively stated rules would ameliorate that problem. Another relates to the possibility that some teachers might be carried away by the ease of the game's implementation to the extent that behavior control becomes the primary objective in the classroom. As a result, one might consider use of the game to maximize short-term change, but then phase out this procedure in favor of another method (e.g., teacher attention) for long-run effects.     

The nature of control by spoken words over visual stimulus selection.

Eight retarded adolescents were trained to select one (a trained S+) of two visual stimuli in response to a spoken word (a trained word). Two different visual stimuli alternated randomly as the S-. To determine if the spoken work was merely a temporal discriminative stimulus for when to respond, or if it also specified which visual stimulus to select, the subjects were given intermittent presentations of untrained (novel) spoken words. All subjects consistently selected the trained S+ in response to the trained spoken word and selected the previous S- in response to the untrained spoken words. It was hypothesized that the subjects were responding away from the trained S+ in response to untrained spoken words, and control by untrained spoken words would not be observed when the trained S+ was not present. The two visual S- stimuli selected on trials of untrained spoken words were presented simultaneously. The untrained spoken words presented on these trials no longer controlled stimulus selections for seven subjects. The results supported the hypothesis that previous control by spoken words was due to responding away from the trained S+ in response to untrained spoken words.     

INTERACTIONS BETWEEN TEACHER GUIDANCE AND CONTINGENT ACCESS TO PLAY IN DEVELOPING PREACADEMIC SKILLS OF DEVIANT PRESCHOOL CHILDREN1

Token-mediated access to play and snacks was made contingent on completion of academic tasks in the Baseline Experiment. This contingency produced stable completion rates that were subsequently doubled, and then tripled, for four deviant children in a special preschool. A reversal design demonstrated that the contingency was functional in maintaining the children's rates of task completion. The Guidance Experiment examined the role of a social event, teacher guidance, in the acquisition of task-completion skills, in a multiple-baseline-across-tasks design (with reversals). The analysis demonstrated that teacher guidance was an important supplement to the token-mediated contingency in establishing significant increases in task completions for a second group of three deviant children in the special class. The importance of teacher guidance was related to the difficulty level of the children's tasks.