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11.
A Bayesian approach to the testing of competing covariance structures is developed. The method provides approximate posterior probablities for each model under consideration without prior specification of individual parameter distributions. The method is based on ayesian updating using cross-validated pseudo-likelihoods. Given that the observed variables are the samefor all competing models, the approximate posterior probabilities may be obtained easily from the chi square values and other known constants, using only a hand calculator. The approach is illustrated using and example which illustrates how the prior probabilities can alter the results concerning which model specification is preferred.  相似文献   
12.
Effects of relative reinforcer frequency on complex color detection   总被引:1,自引:1,他引:0  
Pigeons were trained under a discrete-trials detection procedure in which one of a set of color stimuli was presented on the center key and a single response turned off the stimulus and illuminated two side keys. Single responses to one or the other side key produced occasional reinforcers depending on the value of the color stimulus. In Experiment 1, one color-stimulus set comprised 559, 564, 569, and 574 nm, and right-key pecks were occasionally reinforced following presentations of members of this set. The other stimulus set comprised 579, 584, 589, and 594 nm, and left-key pecks were occasionally reinforced following presentations of members of this set. Across seven experimental conditions, the left/(left + right) relative reinforcer frequency was varied from .1 to .9. In Experiment 2, one stimulus set contained only one member, 574 nm, and right-key responses were occasionally reinforced following its presentation. Over 12 experimental conditions, two manipulations were carried out. First, the number of stimuli comprising the other stimulus set was increased from one (579 nm) to two (579 and 584 nm) to three (579, 584, and 589 nm) and to four (579, 584, 589, and 594 nm), and left-key responses were reinforced occasionally following center-key presentations of members of this set. Second, for each stimulus combination, the left/(left + right) relative reinforcer frequency was varied from .1 to .5 to .9 across three experimental conditions. The principal finding of Experiments 1 and 2 was that reinforcers and stimuli interacted in their effects on behavior. In Experiment 3, pairs of adjacent stimuli (5 nm apart) in the range 559 to 594 nm were presented in each experimental condition, and the left/(left + right) relative reinforcer frequency was held constant at .5. The data from all three experiments were analyzed according to a detection model describing performance in multiple-stimulus two-response procedures. This model provided independent measures of stimulus discriminability, contingency discriminability, and bias. The analysis showed that (a) consistent with the color-naming function, pigeons were better able to discriminate between higher nanometer values than lower nanometer values; (b) their ability to discriminate between the stimuli was independent of the number of wavelengths comprising each stimulus set; (c) they allocated delivered reinforcers very accurately to the previously emitted response; and (d) no consistent biases emerged.  相似文献   
13.
Six pigeons were trained in a discrete-trials signal-detection procedure to discriminate between a fixed-duration stimulus (5 s or 20 s) and a set of variable durations ranging from 2.5 s to 57.5 s in steps of 5 s. For each fixed-duration stimulus, the ratio of reinforcer frequencies contingent upon reporting the fixed versus the variable stimulus was systematically manipulated. Detection performance was well controlled by both the stimulus value and the reinforcer ratio. Both the discriminability between the fixed duration and the set of variable durations, and the discriminability between the fixed duration and each of the variable durations, were independent of the reinforcer-frequency ratio when discriminability was measured as log d. The sensitivity of response bias to reinforcement-ratio changes was independent of the value of the fixed duration, but was not independent of the discriminability of the variable durations from the fixed durations. Under current models, discriminability measures in complex temporal discrimination may be independent of biasing manipulations, but bias measures are not independent of stimulus values.  相似文献   
14.
It is commonly held that even where questionnaire response is poor, correlational studies are affected only by loss of degrees of freedom or precision. We show that this supposition is not true. If the decision to respond is correlated with a substantive variable of interest, then regression or analysis of variance methods based upon the questionnaire results may be adversely affected by self-selection bias. Moreover such bias may arise even where response is 100%. The problem in both cases arises where selection information is passed to the score indirectly via the disturbance or individual effects, rather than entirely via the observable explanatory variables. We suggest tests for the ensuing self-selection bias and possible ways of handling the ensuing problems of inference.The author would like to thank members of the Psychology Department at UWA for references on the illustrative example, namely the effects of sex-stereotyping on achievements in mathematics; thanks are also due to the anonymous reviewers whose comments resulted in material improvements to the paper.  相似文献   
15.
This study examined social skills components that precede the delivery of a skilled overt interpersonal response. Using a cognitive-behavioral systems approach to assertiveness, a task analysis of how women receive and process information in interpersonal situations requiring an assertive response to men was performed. Forty women were assigned to high- or low-assertive groups based on their Rathus Assertiveness Schedule scores. In small group sessions, each woman viewed four videotaped problem situations requiring an assertive response to both pleasant and angry males. After viewing each scene, each woman completed three questionnaires: (a) receiving information, (b) processing-generation of alternatives and decision making, and (c) processing-generation of consequences. High- and low-assertive participants were found to differ in their evaluation of consequences, for response options, particularly how a male would likely to behave to them. High-assertive participants were judged to evaluate more correctly than low-assertive participants the likely behavior of males if response options were implemented. All participants generated more complex alternatives and more assertive responses to situations involving an angry male as compared to a pleasant male. No differences were found between groups in their ability to receive information accurately. Correlational results were supportive of a cognitive-behavioral systems approach of assertion, that is, the emission of a skilled response depends on a chain of preceding responses.Thanks are due to Vida Dyson and Lenard Jason for their comments on an early draft of this paper.  相似文献   
16.
Christians are notably underrepresented in science in part due to long-standing public perceptions of science-religion incompatibility and antireligious bias in science. This research explores whether undergraduates at a Christian university perceive and impose anti-Christian cultural stigma in science. Survey results from 126 biology students revealed that though students generally perceived the culture of science to be anti-Christian, they perceived Christians to have equal opportunities for scientific achievement. Results from a quasi-experimental audit study, in which students evaluated one of two profiles for mock prospective Ph.D. applicants (Christian or undisclosed faith) showed that students did not project anti-Christian stereotypes in terms of competence, hireability, or likeability, but showed some evidence of pro-Christian favorability. Together, this study suggests that the affirmational community of a Christian University may alleviate some negative impacts of anti-Christian stereotypes in academic biology, even as students perceive discrimination against Christians in science and atheists as more scientifically competent.  相似文献   
17.
Previous studies examining the relationship between ingroup bias and resource scarcity have produced heterogeneous findings, possibly due to their focus on the allocation of positive resources (e.g. money). This study aims to investigate whether ingroup bias would be amplified or eliminated when perceived survival resources for counteracting negative stimuli are scarce. For this purpose, we exposed the participants and another confederate of the experimenters (ingroup/outgroup member) to a potential threat of unpleasant noise. Participants received some ‘relieving resources’ to counteract noise administration, the amount of which may or may not be enough for them and the confederate in different conditions (i.e. abundance vs. scarcity). First, a behavioural experiment demonstrated that intergroup discrimination manifested only in the scarcity condition; in contrast, the participants allocated similar amounts of resource to ingroup and outgroup members in the abundance condition, indicating a context-dependent allocation strategy. This behavioural pattern was replicated in a follow-up neuroimaging experiment, which further revealed that when contrasting scarcity with abundance, there was higher activation in the anterior cingulate cortex (ACC) as well as stronger functional connectivity of the ACC with the empathy network (including the temporoparietal junction and medial prefrontal cortex) for ingroup compared to outgroup members. We suggest that ACC activation reflects the mentalizing process toward ingroup over outgroup members in the scarcity condition. Finally, the ACC activation level significantly predicted the influence of resource scarcity on ingroup bias in hypothetical real-life situations according to a follow-up examination.  相似文献   
18.
This article argues that a psychological bias called “focalism” contributes to an overestimation of the differences between political candidates, which in turn increases participation and polarization. Focalism causes people to confuse the allocation of attention to things with the importance of those things. Because attention to politics typically centers on conflict, the result is an exaggeration of differences across the partisan divide. I test this intuition using an experimental design that provides all respondents with all the information they need to estimate how much Joe Biden and Donald Trump objectively disagreed on policy positions just before the 2020 election. I find that shifting attention—toward either those positions the candidates agreed or disagreed with each other on—influences beliefs about the differences between candidates. The effect exceeds that of identifying as a Democrat or as a Republican. Beyond those perceptions, focalism increases turnout intentions, perceptions of election importance, negative feelings towards the out-candidate, and affective polarization.  相似文献   
19.
Nancy Suchman and the colleagues she influenced have produced ground-breaking and attitude-challenging work in understanding how parenting and substance use come together. Dr Suchman and her colleagues make the claim that there is nothing about a substance-use disorder that precludes effective and sensitive caring for children especially with interventions that focus on the parent–child relationship. Suchman's legacy is to highlight how substance use as an illness pulls individuals away from important, caring relationships and limits their giving themselves to those relationships. Restoring the salience of caring relationships and of the individual's ability to care may be as impactful on their substance use as a strict focus on the reduction of drug use and achieving abstinence.  相似文献   
20.
作业中断会对中断后行为绩效产生影响,探讨不同疲劳状态下中断对作业绩效影响的认知机制将有助于完善和发展中断的认知理论。本研究采用事件相关电位(ERP),通过在不同心理疲劳状态下执行数学题任务中断、暂停中断和不中断的空间2-back任务,结合行为数据和ERPs结果,分析作业中断对任务绩效的影响以及心理疲劳在其中的调节作用。实验结果发现,中断后诱发的P200和P300振幅显著提高,作业中断使得主任务的注意力资源下降,任务中断的无关信息干扰了主任务工作记忆,而疲劳状态则进一步加剧了中断对注意资源、工作记忆及行为绩效的负面效应。本研究在揭示作业中断认知过程及疲劳对其影响机理的同时,也支持了中断的目标记忆模型。  相似文献   
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