Change deafness for simultaneous voices

Apparent changes in auditory scenes are often unnoticed. This change deafness phenomenon was examined in auditory scenes that comprise human voices. In two experiments, listeners were required to detect changes between two auditory scenes comprising two, three, and four talkers who voiced four‐syllable words. One of the voices in the first scene was randomly selected and was replaced with a new word in change trials. The rationale was that higher stimulus familiarity conferred by human voices compared to other everyday sounds, together with encoding and memory advantages for verbal stimuli and the modular processing of speech in auditory processing, should positively influence the change detection efficiency, and the change deafness phenomenon should not be observed when listeners are explicitly required to detect the obvious changes. Contrary to the prediction, change deafness was significantly observed in three‐ and four‐talker conditions. This indicates that change deafness occurs in listeners even for highly familiar stimuli. This suggests the limited ability for perceptual organization of auditory scenes comprising even a relatively small number of voices (three or four).     

Choice between single and multiple reinforcers in concurrent-chains schedules

Pigeons responded on concurrent-chains schedules with equal variable-interval schedules as initial links. One terminal link delivered a single reinforcer after a fixed delay, and the other terminal link delivered either three or five reinforcers, each preceded by a fixed delay. Some conditions included a postreinforcer delay after the single reinforcer to equate the total durations of the two terminal links, but other conditions did not include such a postreinforcer delay. With short initial links, preference for the single-reinforcer alternative decreased when a postreinforcer delay was present, but with long initial links, the postreinforcer delays had no significant effect on preference. In conditions with a postreinforcer delay, preference for the single-reinforcer alternative frequently switched from above 50% to below 50% as the initial links were lengthened. This pattern of results was consistent with delay-reduction theory (Squires & Fantino, 1971), but not with the contextual-choice model (Grace, 1994) or the hyperbolic value-added model (Mazur, 2001) as they have usually been applied. However, the hyperbolic value-added model could account for the results if its calculations were expanded to include reinforcers delivered in later terminal links. The implications of these findings for models of concurrent-chains performance are discussed.     

Stronger Relationships, Stronger Communities: Lessons From a Regional Intergroup Grant Initiative

This paper tells the story of an intergroup grant initiative and the neighborhood projects it supported. It highlights the challenges of race and power, in conjunction with other overlapping identities and forms of discrimination. The demographics of the greater Goodland region have changed dramatically over the last few years and decades. The life for traditionally European American and African American communities is being altered by a steady influx of new immigrants from Africa, Asia, and Latin America. This paper discusses a philanthropic community's response to these changes and within this, two specific neighborhood-based responses. The lessons and insights described in this paper, told by the initiative's evaluator and advisory council co-chair, are drawn from five years' of systematic data collection and analysis, focused observations, and the reflections of other participants in the initiative.

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Rate, Probability and Matching: Comments on ��The Identities Hidden in the Matching Laws, and Their Uses�� by David Thorne

David Thorne's (2010) article, “The Identities Hidden In The Matching Laws, And Their Uses” performs a valuable service in pointing out alternative expressions of matching. However, some identities tend to obscure rather than illuminate empirical relationships. Three such problematic instances are discussed: interresponse time as a function of interval and ratio schedule parameters; probability equality as implying rate matching; the apparent simplicity of probabilistic functions, as opposed to response rate functions, of reinforcement rate.     

A Signal Detection Model for Multiple-Choice Exams

A model for multiple-choice exams is developed from a signal-detection perspective. A correct alternative in a multiple-choice exam can be viewed as being a signal embedded in noise (incorrect alternatives). Examinees are assumed to have perceptions of the plausibility of each alternative, and the decision process is to choose the most plausible alternative. It is also assumed that each examinee either knows or does not know each item. These assumptions together lead to a signal detection choice model for multiple-choice exams. The model can be viewed, statistically, as a mixture extension, with random mixing, of the traditional choice model, or similarly, as a grade-of-membership extension. A version of the model with extreme value distributions is developed, in which case the model simplifies to a mixture multinomial logit model with random mixing. The approach is shown to offer measures of item discrimination and difficulty, along with information about the relative plausibility of each of the alternatives. The model, parameters, and measures derived from the parameters are compared to those obtained with several commonly used item response theory models. An application of the model to an educational data set is presented.     

Boundary Issues in Academia: Student Perceptions of Faculty—Student Boundary Crossings

Boundary crossings in academia are rarely addressed by university policy despite the risk of problematic or unethical faculty—student interactions. This study contributes to an understanding of undergraduate college student perceptions of appropriateness of faculty—student nonsexual interactions by investigating the influence of gender and ethnicity on student judgments of the appropriateness of numerous hypothetical interactions. Overall, students deemed the majority of interactions as inappropriate. Female students judged a number of interactions as more inappropriate than did male students, and with a few exceptions, Mexican American and Anglo American students were similar in their ratings of the appropriateness of faculty—student interactions. These findings suggest that universities need to be proactive in establishing guidelines concerning faculty-student boundary crossings.     

Managing Nonsexual Multiple Relationships in University Counseling Centers: Recommendations for Graduate Assistants and Practicum Students

Graduate students typically serve in a wide variety of positions throughout their course of study in an academic setting. Because of the large number of roles assumed, graduate students may encounter several ethical dilemmas unique to the academic setting, particularly dilemmas regarding nonsexual multiple relationships. Although the topic of multiple relationships and psychologists has been extensively discussed in the literature, fewer articles have focused on the potential for nonsexual multiple relationships between graduate assistants, practicum students, and undergraduate students. This article focuses on the unique ethical dilemmas and challenges experienced by graduate assistants completing their practica at University Counseling Centers and provides recommendations for evaluating and managing nonsexual multiple relationships with undergraduate students.     

The Prediction of Students' Satisfaction with Community College Vocational Training

The present study was conducted with 1,632 college vocational students in North Carolina to test the job satisfaction postulate of Rusbult's (1980a) investment model. The model postulate, that satisfaction is a function of perceived positive and negative outcomes, received support and proved to be defensible even after controlling for a broad array of situational variables. This postulate has also received empirical support from studies of satisfaction with business relationships, friendships, and romantic associations. The present study also introduced a new measure of outcomes: the Perceived Outcomes of College Life measure.     

Optimal versus heuristic planning of object manipulations: A review and a computational model of the continuous end-state comfort effect

Human beings select actions that facilitate the execution of later actions. For example, humans tend to select grasps that ensure that forthcoming object manipulations end in a comfortable posture (“end-state comfort effect”). Basic experimental results and their explanation within the optimal control framework are reviewed. I conclude that the discrete grasp selection tasks, which are commonly used to study anticipatory planning, leave room for alternative explanations. Moreover, the results of seven experiments employing a continuous grasp selection task seem incompatible with the optimal control (of end-state comfort) account. I introduce the weighted integration of multiple biases (WIMB) model, which accounts for many aspects of the selection of human grasp orientations in continuous tasks. Additionally, it accounts for the precision effect and hysteresis effect. The model shows that the brain may rely on a simple heuristic and does not actually has to anticipate the end-state of a movement to select effective grasps for object manipulations.