García A  Benjumea S 《Journal of the experimental analysis of behavior》2006,86(1):65-80

In Experiment 1, 10 pigeons were exposed to a successive symbolic matching-to-sample procedure in which the sample was generated by the pigeons' own behavior. Each trial began with both response keys illuminated white, one being the \"correct\" key and the other the \"incorrect\" key. The pigeons had no way of discriminating which key was correct and which incorrect, since these roles were assigned on a random basis with the same probability of 0.5 for each key. A fixed ratio of five responses was required on the correct key. However, each time the pigeon pecked the incorrect key, the correct key response counter reset. Five consecutive pecks on the correct key was the only way to end this component, and switch off both key lights. Two seconds later, these same keys were illuminated again, one green and the other red (comparison stimuli). Now, if the correct white key had been on the left, a peck at one color produced food, and if the correct white key had been on the right, a peck at the other color produced food. When the pigeons had learned this discrimination, they were exposed to several symmetry tests (simultaneous presentations of both keys illuminated the same color-i.e., both red or both green), in order to interchange the sample with the comparison stimuli. In Experiment 2, the importance of requiring discrimination between the samples and between the comparisons was analyzed. In Experiment 3, we compared the results of Experiment 1 with a slightly different experiment, which resulted in discrimination of key position, an exteroceptive stimulus. The results showed that symmetry emerged only when different responses were used as samples.  相似文献   

    

Shimizu H 《Journal of the experimental analysis of behavior》2006,86(2):239-251

This study tested the notion that an equivalence relation may include a response when differential responses are paired with stimuli presented during training. Eight normal adults learned three kinds of computer mouse movements as differential response topographies (R1, R2, and R3). Next, in matching-to-sample training, one of the response topographies was used to select a comparison stimulus B (B1, B2, or B3) conditionally upon presentation of sample stimulus A (A1, A2, or A3), and to select stimulus D (D1, D2, or D3) conditionally upon presentation of stimulus C (C1, C2, or C3). After two sample-comparison-response relations (ABR and CDR) were established, 18 sample-comparison relations were tested (BA, DC, RA, RB, RC, RD, AC, CA, AD, DA, BC, CB, BD, DB, AA, BB, CC, and DD). In the RA, RB, RC, and RD tests, the differential responses (R1, R2, and R3) were used as sample stimuli. All subjects made class-consistent comparison selections in the tests. This study provides evidence that responses may become members of an equivalence class.  相似文献   

    

Peña T  Pitts RC  Galizio M 《Journal of the experimental analysis of behavior》2006,85(2):203-221

Identity matching-to-sample has been difficult to demonstrate in rats, but most studies have used visual stimuli. There is evidence that rats can acquire complex forms of olfactory stimulus control, and the present study explored the possibility that identity matching might be facilitated in rats if olfactory stimuli were used. Four rats were trained on an identity match-to-sample procedure with odorants mixed in cups of sand as stimuli. Digging in the sample cup produced two comparison cups, and digging in the comparison cup that contained the same scent as the sample was reinforced. When criterion accuracy levels were reached, novel stimuli were added to the baseline training regimen. All 4 rats reached terminal performance of above 90% correct matching with more than 20 different baseline stimuli and matched novel stimulus combinations with above-chance accuracy; 3 of the 4 rats matched novel stimuli at levels significantly above chance. Accurate matching performance was demonstrated both with 2- and 3-comparison procedures. These results suggest that generalized matching-to-sample can be observed in rats when olfactory stimuli are used and, furthermore, that multiple-exemplar training may be important for its emergence.  相似文献   

    

Ehtibar?N.?Dzhafarov  "mailto:ehtibar@purdue.edu  " title=  "ehtibar@purdue.edu  " itemprop=  "email  " data-track=  "click  " data-track-action=  "Email author  " data-track-label=  "  ">Email author  Hans?Colonius 《Psychometrika》2006,71(2):365-386

We describe a principled way of imposing a metric representing dissimilarities on any discrete set of stimuli (symbols, handwritings, consumer products, X-ray films, etc.), given the probabilities with which they are discriminated from each other by a perceiving system, such as an organism, person, group of experts, neuronal structure, technical device, or even an abstract computational algorithm. In this procedure one does not have to assume that discrimination probabilities are monotonically related to distances, or that the distances belong to a predefined class of metrics, such as Minkowski. Discrimination probabilities do not have to be symmetric, the probability of discriminating an object from itself need not be a constant, and discrimination probabilities are allowed to be 0’s and 1’s. The only requirement that has to be satisfied is Regular Minimality, a principle we consider the defining property of discrimination: for ordered stimulus pairs (a,b), b is least frequently discriminated from a if and only if a is least frequently discriminated from b. Regular Minimality generalizes one of the weak consequences of the assumption that discrimination probabilities are monotonically related to distances: the probability of discriminating a from a should be less than that of discriminating a from any other object. This special form of Regular Minimality also underlies such traditional analyses of discrimination probabilities as Multidimensional Scaling and Cluster Analysis. This research was supported by the NSF grant SES 0318010 (E.D.), Humboldt Research Award (E.D.), Humboldt Foundation grant DEU/1038348 (H.C. & E.D.), and DFG grant Co 94/5 (H.C.).  相似文献   

    

Wizdom Powell Hammond 《American journal of community psychology》2010,45(1-2):87-106

The current study proposed and tested a conceptual model of medical mistrust in a sample of African American men (N = 216) recruited primarily from barbershops in the Midwest and Southeast regions of the United States. Potential psychosocial correlates were grouped into background factors, masculine role identity/socialization factors, recent healthcare experiences, recent socioenvironmental experiences (e.g., discrimination), and healthcare system outcome expectations (e.g., perceived racism in healthcare). Direct and mediated relationships were assessed. Results from the hierarchical regression analyses suggest that perceived racism in healthcare was the most powerful correlate of medical mistrust even after controlling for other factors. Direct effects were found for age, masculine role identity, recent patient–physician interaction quality, and discrimination experiences. Also, perceived racism in healthcare mediated the relationship between discrimination experiences and medical mistrust. These findings suggest that African American men’s mistrust of healthcare organizations is related to personal characteristics, previous negative social/healthcare experiences, and expectations of disparate treatment on the basis of race. These findings also imply that aspects of masculine role identity shape the tone of patient–physician interactions in ways that impede trust building processes.  相似文献   

    

Silvia Bonaccio  Charlie L. Reeve   《Organizational behavior and human decision processes》2006,101(2):200-214

This study examined whether, and if so by what mechanism, changes in relative attribute variability can elicit a decoy effect. We argue and demonstrate that when only the relative variability of the attribute values in the choice set are manipulated (i.e., a frequency-only manipulation), decoy effects are observed consistent with predictions made by the Context-Dependent Weighting hypothesis as formulated by Huber et al. [Huber, J., Payne, J.W., & Puto, C. (1982). Adding asymmetrically dominated alternatives: Violations of regularity and the similarity hypothesis. Journal of Consumer Research, 10, 31–44.]. On the surface, our results appear to contravene earlier refutations of the Context-Dependent Weighting model. However, additional results from explicit tests of the purported casual mechanism (i.e., context-dependent attribute weight changes) suggest that decision-makers’ perceived importance of dimensions did not shift in response to our manipulation, making the Loss Aversion model a more viable explanation. Finally, results from a written protocol analysis suggest that many decision-makers were unaware, or at least unable to accurately verbalize, the influence of the context. Most decision-makers purported that they had made choices on the basis of their a priori beliefs about the relative importance of attributes despite the fact that there was clear evidence of context effects. Overall, our results underscore the importance of gathering multiple types of evidence for preference shifts in order to fully understand the mechanisms underlying decision-making.  相似文献   

    

Antonia C. Lyons  Helen Madden  Kerry Chamberlain  Stuart Carr 《Journal of community & applied social psychology》2011,21(1):14-27

Previous research has demonstrated that talk about immigration can function to produce, reproduce and stabilize racism (Capdevila & Callaghan, 2008 ). In New Zealand (NZ), changes in immigration policy have seen a rapid increase in diverse groups of migrants with varied cultural backgrounds entering the country in the past two decades. Given its unique colonial history and ‘settler nationality in a bicultural nation’ (Bell, 2009 ), we explored how young NZ adults talk about and produce meanings and understandings of immigration, immigrants and cultural diversity. Appealing to notions of NZ as ‘one society’, as English speaking, and as English looking participants constructed NZ, NZ national identity and the NZ economy in particular ways. This constituted a nationalist rhetoric that was taken up in common‐sense ways by participants to legitimize racist talk whilst simultaneously acting to locate participants themselves as reasonable and moral individuals. It is concluded that nationalist discourses function to reinforce patterns of social dominance and perpetuate the notion of New Zealanders as largely white, European‐looking and English‐speaking. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

    

Gallagher S  Alsop B 《Journal of the experimental analysis of behavior》2001,75(2):183-203

In two detection experiments, university students reported whether the second of two sequentially presented tones was longer or shorter than the first by responding to stimuli presented on a touch screen. Stimulus disparity and response disparity were manipulated to compare their effects on measures of discrimination and response bias when the reinforcement ratio for correct responses was asymmetric. Choice stimuli consisted of squares filled with different pixel densities. Response disparity was manipulated by varying the difference in density between the two choice stimuli. In both experiments, decreasing stimulus disparity reduced discrimination but had no consistent effect on bias. Decreasing response disparity also reduced discrimination in both experiments, and often reduced estimates of bias. The effects of response disparity on bias were most clear in Experiment 2, in which a greater overall level of response disparity was arranged. The data show that, like corresponding research with pigeons, detection performance of human subjects can be conceptualized as discriminated operants.  相似文献   

    

Walpole CW  Roscoe EM  Dube WV 《Journal of applied behavior analysis》2007,40(4):707-712

This study extends previous work on the use of differential observing responses (DOR) to remediate atypically restricted stimulus control. A participant with autism had high matching-to-sample accuracy scores with printed words that had no letters in common (e.g., cat, lid, bug) but poor accuracy with words that had two letters in common (e.g., cat, can, car). In the DOR intervention, she matched the distinguishing letters of the overlapping words (e.g., t, n, r) immediately prior to matching the whole words. Accuracy scores improved, and accuracy remained high when DOR requirements were withdrawn.  相似文献   

    

McHugh L  Reed P 《Journal of the experimental analysis of behavior》2007,88(3):369-380

Stimulus overselectivity refers to the phenomenon whereby stimulus control over behavior is exerted only by a limited subset of the total number of stimuli present during discrimination learning. It often is displayed by individuals with autistic spectrum disorders or learning disabilities, but is not exclusive to those groups. The present studies investigated the impact of aging on stimulus control and overselectivity. Three age groups--18-22, 47-55, and 70-80 year olds-were studied in two experiments. All participants were trained on a simple discrimination task, randomly assigned to one of two conditions (either with or without a distractor task), and then tested for the emergence of overselectivity (Experiment 1). In Experiment 2 responding controlled by the overselected stimulus elements was reduced by introducing a verbal punisher. In subsequent tests, control of behavior by the previously underselected elements from Experiment 1 was enhanced across the two younger age groups but not the oldest group of participants. The results are discussed in relation to the attention-deficit and overshadowing accounts of overselectivity.  相似文献