Fields L  Watanabe-Rose M 《Journal of the experimental analysis of behavior》2008,89(3):359-381

By definition, all of the stimuli in an equivalence class have to be functionally interchangeable with each other. The present experiment, however, demonstrated that this was not the case when using post-class-formation dual-option response transfer tests. With college students, two 4-node 6-member equivalence classes with nodal structures of A-->B-->C-->D-->E-->F were produced by training AB, BC, CD, DE, and EF. Then, unique responses were trained to the C and D stimuli in each class. The responses trained to C generalized to B and A, while the responses trained to D generalized to E and F. Thus, each 4-node 6-member equivalence class was bifurcated into two 3-member functional classes: A-->B-->C and D-->E-->F, with class membership precisely predicted by nodal structure. A final emergent relations test documented the intactness of the underlying 4-node 6-member equivalence classes. The coexistence of the interchangeability of stimuli in an equivalence class and the bifurcation of such a class in terms of nodal structure was explained in the following manner. The conditional discriminations that are used to establish a class also imposes a nodal structure on the stimuli in the class. Thus, the stimuli in the class acquire two sets of relational properties. If the format of a test trial allows only one response option per class, responding on those trials will be in accordance with class membership and will not express the effects of nodal distance. If the format of a test trial allows more than one response option per class, responding on those trials will be determined by the nodal structure of the class. Thus, the relational properties expressed by the stimuli in an equivalence class are determined by the discriminative function served by the format of a test trial.  相似文献   

    

Lazareva OF  Smirnova AA  Bagozkaja MS  Zorina ZA  Rayevsky VV  Wasserman EA 《Journal of the experimental analysis of behavior》2004,82(1):1-19

Eight crows were taught to discriminate overlapping pairs of visual stimuli (A+ B-, B+ C-, C+ D-, and D+ E-). For 4 birds, the stimuli were colored cards with a circle of the same color on the reverse side whose diameter decreased from A to E (ordered feedback group). These circles were made available for comparison to potentially help the crows order the stimuli along a physical dimension. For the other 4 birds, the circles corresponding to the colored cards had the same diameter (constant feedback group). In later testing, a novel choice pair (BD) was presented. Reinforcement history involving stimuli B and D was controlled so that the reinforcement/nonreinforcement ratios for the latter would be greater than for the former. If, during the BD test, the crows chose between stimuli according to these reinforcement/nonreinforcement ratios, then they should prefer D; if they chose according to the diameter of the feedback stimuli, then they should prefer B. In the ordered feedback group, the crows strongly preferred B over D; in the constant feedback group, the crows' choice did not differ significantly from chance. These results, plus simulations using associative models, suggest that the orderability of the postchoice feedback stimuli is important for crows' transitive responding.  相似文献   

    

Alsop B 《Journal of the experimental analysis of behavior》2004,82(1):57-69

Quantitative analyses of stimulus control and reinforcer control in conditional discriminations and delayed matching-to-sample procedures often encounter a problem; it is not clear how to analyze data when subjects have not made errors. The present article examines two common methods for overcoming this problem. Monte Carlo simulations of performance demonstrated that both methods introduced systematic deviations into the results, and that there were genuine risks of drawing misleading conclusions concerning behavioral models of signal detection and animal short-term memory.  相似文献   

    

Crowley MA  Donahoe JW 《Journal of the experimental analysis of behavior》2004,82(2):143-159

Choice typically is studied by exposing organisms to concurrent variable-interval schedules in which not only responses controlled by stimuli on the key are acquired but also switching responses and likely other operants as well. In the present research, discriminated key-pecking responses in pigeons were first acquired using a multiple schedule that minimized the reinforcement of switching operants. Then, choice was assessed during concurrent-probe periods in which pairs of discriminative stimuli were presented concurrently. Upon initial exposure to concurrently presented stimuli, choice approximated exclusive preference for the alternative associated with the higher reinforcement frequency. Concurrent schedules were then implemented that gave increasingly greater opportunities for switching operants to be conditioned. As these operants were acquired, the relation of relative response frequency to relative reinforcement frequency converged toward a matching relation. An account of matching with concurrent schedules is proposed in which responding exclusively to the discriminative stimulus associated with the higher reinforcement frequency declines as the concurrent stimuli become more similar and other operants-notably switching-are acquired and generalize to stimuli from both alternatives. The concerted effect of these processes fosters an approximate matching relation in commonly used concurrent procedures.  相似文献   

    

McMillan DE  Hardwick WC  Li M 《Journal of the experimental analysis of behavior》2002,77(1):91-104

Pigeons were trained to discriminate 5 mg/kg pentobarbital from saline under concurrent variable-ratio (VR) VR schedules, in which responses on the pentobarbital-biased lever were reinforced under the VR schedule with the smaller response requirements when pentobarbital was given before the session, and responses on the saline-biased key were reinforced under the VR schedule with the larger response requirements. When saline was administered before the session, the reinforcement contingencies associated with the two response keys were reversed. When responding stabilized under concurrent VR 20 VR 30, concurrent VR 10 VR 40, or concurrent VR 5 VR 50 schedules, pigeons responded almost exclusively on the key on which fewer responses were required to produce the reinforcer. When other doses of pentobarbital and other drugs were substituted for the training dose, low doses of all drugs produced responding on the saline-biased key. Higher doses of pentobarbital and chlordiazepoxide produced responding only on the pentobarbital-biased key, whereas higher doses of ethanol and phencyclidine produced responding only on this key less often. d-Amphetamine produced responding primarily on the saline-biased key. When drugs generalized to pentobarbital, the shape of the generalization curve under concurrent VR VR schedules was more often graded than quantal in shape. Thus, drug discrimination can be established under concurrent VR VR schedules, but the shapes of drug-discrimination dose-response curves under concurrent VR VR schedules more closely resemble those seen under interval schedules than those seen under fixed-ratio schedules. Graded dose-response curves under concurrent VR VR schedules may relate to probability matching and difficulty in discriminating differences in reinforcement frequency.  相似文献   

    

Beran MJ  Washburn DA 《Journal of the experimental analysis of behavior》2002,78(3):497-508

Three chimpanzees performed a computerized matching-to-sample task in which samples were photographs of items and comparison stimuli were geometric symbols called lexigrams. In Experiment 1, samples were either defined (i.e., they represented items that were associated already with a specific lexigram label by the chimpanzees) or undefined (i.e., they did not have an already learned association with a specific lexigram). On each trial, the foil (incorrect) comparison could be either a defined or an undefined lexigram. All 3 chimpanzees selected the correct comparison for undefined samples at a level significantly better than chance only when the foil comparison was defined. In Experiment 2, three comparisons were presented on each trial, and in Experiment 3, four comparisons were presented on each trial. For Experiments 2 and 3, the foil comparisons consisted of either defined or undefined comparisons or a mixture of both. For these two experiments, when the chimpanzees were presented with an undefined sample, they typically made selections of only undefined comparisons. These data indicate that the chimpanzees responded through use of exclusion. A final experiment, however, indicated that, despite the use of exclusion to complete trials with undefined samples correctly, the chimpanzees did not learn new associations between undefined samples and comparisons.  相似文献   

    

Koji Sakai 《The Japanese psychological research》2003,45(2):122-128

Abstract: A two-interval forced-choice of constant stimuli was used to measure the point of subjective equality (PSE) and discrimination threshold for standard contour curvature (1.91, 3.24 deg⁻¹) held in short-term visual memory (STVM). At both standard curvatures, the PSE for remembered curvature was nearly constant for standard curvature from 2 s to 16 s retention intervals, while the discrimination threshold increased as a linear function of retention interval. These results show that the decay in STVM for contour curvature is due to the noisy representation of curvature, neither to fading of the represented curvature nor to converging to the constant curvature. Furthermore, the Weber fraction was nearly constant for both standard curvatures at any delay from 2 to 16 s.  相似文献   

    

O'Donnell J  Saunders KJ 《Journal of the experimental analysis of behavior》2003,80(1):131-157

The study of equivalence relations exhibited by individuals with mental retardation and language limitations holds the promise of providing information of both theoretical and practical significance. We reviewed the equivalence literature with this population, defined in terms of subjects having moderate, severe, or profound mental retardation. The literature includes 55 such individuals, most of whom showed positive outcomes on equivalence tests. The results to date suggest that naming skills are not necessary for positive equivalence test outcomes. Thus far, however, relatively few subjects with minimal language have been studied. Moreover, we suggest that the scientific contributions of studies in this area would be enhanced with better documentation of language skills and other subject characteristics. With recent advances in laboratory procedures for establishing the baseline performances necessary for equivalence tests, this research area is poised for rapid growth.  相似文献   

    

Monteiro MB  de Fran?a DX  Rodrigues R 《International journal of psychology》2009,44(1):29-39

The present research examined the developmental course of racial behaviours in childhood. It tested the hypothesis that White children's expressions of racial prejudice do not necessarily decline in middle childhood due to the development of particular cognitive skills but that instead, as argued by the socio-normative approach, children older than seven will go on expressing prejudiced attitudes under appropriate conditions. This would be explained by the presence of an anti-racism norm, along with the existence of values promoting equal rights, which impede blatant expressions of racism. In the first study 283 White children aged 6-7 and 9-10 years performed a task of resource allocation to White and Black target children in conditions of high (White interviewer was present) or low (White interviewer was absent) salience of the anti-racist norm. The 6- to 7-year-old children discriminated against the Black target in both conditions whereas older children discriminated against the Black child only when the anti-racist norm was not salient. In Study 2, 187 White children aged 6-7 and 9-10 years performed the same resource allocation task in conditions of explicit activation of similarity vs dissimilarity or egalitarian vs merit-based norms regarding race relations. Supporting the hypothesis of the role of racist or anti-racist norms on the expression of intergroup discrimination, results have again shown that 6- to 7-year-old children discriminated against the Black target in both conditions while older children presented significantly different prejudiced/nonprejudiced behaviours consistent with the activated norms. These results were discussed in terms of the need for a reanalysis of the assumptions and research results of the cognitive-developmental theory and of further developments in the socio-normative approach regarding the development of prejudice in childhood.  相似文献   

    

Li Li  Li‐Jung Liang  Chunqing Lin  Zunyou Wu  Yi Wen 《International journal of psychology》2009,44(6):443-450

This study examined HIV/AIDS‐related stigma among Chinese service providers by comparing their personal attitudes toward people living with HIV/AIDS with their perception of social norms related to people living with HIV/AIDS. We randomly selected three provincial hospitals, four city/prefecture hospitals, 10 county hospitals, 18 township health clinics, and 54 village clinics from Yunnan, China. Doctors and nurses were randomly sampled proportionally to the doctor–nurse ratio of each hospital or clinic. Lab technicians were over‐sampled in order to include an adequate representation in the analysis. A total of 1,101 service providers participated in a voluntary, anonymous survey where demographic characteristics, individual attitude and perceived social norms toward people living with HIV/AIDS, discrimination intent at work, general prejudicial attitude and knowledge on HIV/AIDS were measured. A majority of the sample demonstrated a similarity between their personal views and what they thought most people in society believe. Multiple logistic regressions revealed that participants who were younger or reported personal contact with people living with HIV/AIDS were significantly more likely to report personal attitudes toward the population that were more liberal than their perceived social norms. Holding a more liberal personal attitude toward people living with HIV/AIDS than perceived social norms was significantly and negatively related to the level of discrimination intent at work, perceived discrimination at interpersonal level and the level of general prejudicial attitude toward people living with HIV/AIDS. Results underscored the importance of understanding social norms and personal attitudes in studying HIV‐related stigma and called for the incorporation of existing human capital into future HIV stigma reduction programs.  相似文献