Stimulus control topographies and tests of symmetry in pigeons

Pigeons were tested for symmetry after A-B training under conditions designed to avoid problems that may prevent its emergence, namely the change of stimulus location in testing relative to training and the lack of requisite discrimination training. In Experiment 1, samples appeared in two locations during baseline training to minimize the impact of stimulus location. Experiments 2 and 3 included multiple-location training along with additional identity and symbolic matching training, respectively, to explicitly train all of the simultaneous and successive stimulus discriminations required for testing. Experiment 4 provided reinforcement for symmetrical matching relations with some stimulus sets (with multiple-location training) prior to symmetry testing with different sets. In all experiments, pigeons showed no evidence of symmetry despite the fact that baseline (A-B) matching transferred to novel locations. Additional tests for reflexivity (Experiment 2) yielded similar outcomes. These results indicate that the change in stimulus location is not the sole reason that pigeons do not show symmetry and increase the plausibility of arguments that symmetry and other indexes of stimulus equivalence may be beyond the capabilities of the pigeon.     

Naming and categorization in young children: vocal tact training

In three experiments, 2- to 4-year-old children, following pretraining with everyday objects, were presented with arbitrary stimuli of differing shapes. In Experiment 1A, 9 subjects were trained one common tact response, "zag," to three of these and a second tact, "vek," to another three. In category match-to-sample Test 1, 4 subjects sorted accurately when required only to look at the sample before selecting from five comparisons. The remaining 5 subjects succeeded in Test 2, in which they were required to tact the sample before selecting comparisons. Experiment 1B showed, for 2 of these subjects, that tact training with 12 arbitrary stimuli established two six-member classes that were still intact 6 weeks later. In Experiment 2, 3 new subjects participated in a common tact training procedure that ensured that none of the exemplars from the same class were presented together prior to the test for three-member classes. Two subjects passed category Test 1 and the third passed Test 2. Tests showed subjects' listener behavior in response to hearing /zog/ and /vek/ to be in place. These experiments indicate that common naming is effective in establishing arbitrary stimulus classes and that category match-to-sample testing provides a robust measure of categorization.     

Testing for symmetry in the conditional discriminations of language-trained chimpanzees

If subjects are taught to match Stimulus A to B and then, without further training, match B to A, they have passed a test of symmetry. It has been suggested that non-humans' lack of success on symmetry tests might be overcome by giving them a history of symmetry exemplar training, that is, by directly teaching a large number of conditional relations (e.g., AB, CD, EF,...) and also directly training the "reverse" of these relations (e.g., BA, DC, FE,...). The chimpanzee subjects of the present study, Sherman, Austin, and Lana, had already received extensive symmetry exemplar training as a result of attempts to teach a selection-based language system of lexigrams. The present study systematically subjected 2 of these chimps (Sherman and Lana), for the first time, to standard symmetry tests in controlled conditions. Both chimps failed the tests, even when their correct responses on test trials were reinforced. The findings do not support the exemplar training hypothesis, and cast doubt upon whether the chimps can pass tests of stimulus equivalence.     

Treatment of covert food stealing in an individual with Prader-Willi syndrome

Covert food stealing is common among individuals with Prader-Willi syndrome. We found that verbal reprimands, delivered contingent upon eating prohibited foods, were sufficient to decrease the food stealing of a girl with Prader-Willi syndrome. Warning stimuli were then used to help her discriminate between permitted and prohibited foods during sessions in which food stealing was not directly observed. This procedure resulted in decreases in food stealing from containers labeled with the warning stimuli.     

Further evaluation of low-ranked items in stimulus-choice preference assessments

The generality of the findings reported by DeLeon, Iwata, and Roscoe (1997) was examined by conducting two stimulus-choice preference assessments, the second of which evaluated low-ranked items from the initial assessment. Results for the 2 participants suggested that supplementary assessments of low-ranked items may be useful for identifying a wider variety of reinforcing stimuli.     

Equivalence relations and the reinforcement contingency

Where do equivalence relations come from? One possible answer is that they arise directly from the reinforcement contingency. That is to say, a reinforcement contingency produces two types of outcome: (a) 2‐, 3‐, 4‐, 5‐, or n‐term units of analysis that are known, respectively, as operant reinforcement, simple discrimination, conditional discrimination, second‐order conditional discrimination, and so on; and (b) equivalence relations that consist of ordered pairs of all positive elements that participate in the contingency. This conception of the origin of equivalence relations leads to a number of new and verifiable ways of conceptualizing equivalence relations and, more generally, the stimulus control of operant behavior. The theory is also capable of experimental disproof.     

An evaluation of a brief multiple-stimulus preference assessment with adolescents with emotional-behavioral disorders in an educational setting

Brief multiple-stimulus-without-replacement (MSWO) preference assessments were conducted with 3 adolescent boys with emotional-behavioral disorders in the context of their public school educational program. The reinforcing effects of stimuli identified as high, medium, and low preference were then evaluated using an alternating treatments design in which, following an initial baseline, stimuli were delivered contingent on on-task behavior. High-preference stimuli produced the highest percentages of on-task behavior for all 3 participants.     

Establishing derived requesting skills in adults with severe developmental disabilities

This project examined whether a history of reinforced relational responding would result in derived requesting skills in 3 adults with disabilities. Participants were first taught to request preferred items using pictures; they were then taught conditional discriminations between pictures and their dictated names and between dictated names and their corresponding text. Finally, requests for preferred items using corresponding text were evaluated. All 3 participants demonstrated derived requesting skills.     

Using Methods That Matter: The Impact of Reflection,Dialogue, and Voice

In recent years, the field of community psychology has given considerable attention to how research and evaluation methods should be designed to support our goals of empowerment and social justice. Yet, as a field, we have given much less attention to whether the use of our methods actually achieves or supports our empowerment agenda. With the primary purpose of beginning to establish the norm of reporting on the impacts of our methods, this paper reports on the findings from interviews of 16 youth and adults who had participated in one participatory evaluation method (Photovoice). Two specific questions were examined: (1) What is the impact of participating in a Photovoice effort; and (2) How does the method of Photovoice foster these impacts? Overall, participants noted that they were significantly affected by their experiences as photographers and through their dialogue with neighbors during Photovoice group sessions. Impacts ranged from an increased sense of control over their own lives to the emergence of the kinds of awareness, relationships, and efficacy supportive of participants becoming community change agents. According to participants, Photovoice fostered these changes by (a) empowering them as experts on their lives and community, (b) fostering deep reflection, and (c) creating a context safe for exploring diverse perspectives. The implications of these findings for the science and practice of community psychology are discussed.     

AJCP as a Vehicle for Improving Community Life: An Historic–Analytic Review of the Journal’s Contents

The current article is an analysis of the research represented in American Journal of Community Psychology (AJCP) from 1993 to 1998, including a comparison to two previously published analytic reviews by Lounsbury et al. (J. W. Lounsbury, D. S. Leader, E. P. Meares, & M. P. Cook, 1980) and Speer et al. (P. Speer, A. Dey, P. Griggs, C. Gibson, B. Lubin, & J. Hughey, 1992), respectively. Observed trends are examined with references to major epistemological frameworks and methods used to define community psychology. Four guiding principles were examined to determine the representation of the epistemological frameworks of the articles published in the journal. The frameworks include social action, human diversity and cultural relativity, person–environmental fit, and methodological procedures. The results document the transition of community psychology from its early beginnings to an independent field conducting research consistent with the values articulated at the Swampscott Conference. This paper also comments on how well, after three decades of publication, the journal has served as a vehicle for improving community life.