Increasing Low-Responding Students’ Participation in Class Discussion

Students in six sections of a large undergraduate class were asked to record their class comments on notecards in all course units. Additionally, in some units, they received points toward their course grade based on their reported comments in class discussion. The study was conducted over a two-semester period, with slight variation in both the recording and crediting procedures across the two semesters. The primary goal of the study was to determine the effects of two credit and self-recording arrangements on initially low-responding students’ subsequent participation in class discussion (first semester n = 49, second semester n = 45). A higher percentage of low-responding students reported participating in class discussion when credit was given for participation than when no credit was awarded. Nonetheless, 39% of the initially low-responding students the first semester and 38% of the initially low-responding students the second semester did not participate in class discussion in any phase of the study.     

The effects of reinforcer magnitude in the preceding and upcoming ratios on between‐ratio pausing in multiple,mixed, and single fixed‐ratio schedules

Hens responded under multiple fixed‐ratio schedules with equal response requirements and either a 1‐s or a 6‐s reinforcer. Upcoming reinforcer size was indicated by key color. Components were presented in a quasirandom series so that all four component transitions occurred. Postreinforcement pauses were affected by the upcoming and preceding reinforcer size, with longer pauses after large reinforcers followed by small reinforcers than when followed by large ones, and longer pauses after small reinforcers that were followed by small reinforcers rather than large ones. Pauses increased with fixed‐ratio size and the effects of reinforcer size were larger the larger the ratio. When reinforcer size was not signaled—mixed fixed‐ratio schedules—pauses were shorter after small than after large reinforcers. Signalling the upcoming reinforcer attenuated the effect of the previous reinforcer size on pause duration when small was followed by small and when either small or large by large, but enhanced the effect when large was followed by small. There was no effect of reinforcer size on pause duration when single fixed‐ratio schedules were arranged. The effects of reinforcer size on pauses depends on the size and range of the fixed ratios as well as the exact procedures used in the study.     

MK-801 improves retention in aged rats: implications for altered neural plasticity in age-related memory deficits

Alterations in N-methyl-d-aspartate receptor (NMDAR)-dependent synaptic plasticity, characteristic of aged rodents, may contribute to impaired memory with advanced age. The purpose of the current research was to examine whether NMDARs contribute to rapid forgetting on a spatial memory task. Aged (22-24 months) and adult (3-6 months) male Fischer 344 rats received 18 training trials, over a period of 3 to 4 h, on the spatial version of the Morris water maze. Immediately after training, a standard free-swim probe trial was administered to assess the acquisition of spatial bias, which was determined by the percent of time spent in the goal quadrant and the number of platform crossings. Rats then received injections of the noncompetitive NMDAR antagonist, (+)-10, 11-dihydro-5methyl-5H-dibenzo(a,b)cycloheptene-5,10 imine (MK-801, 0. 05 mg/kg, i.p.), or a vehicle injection of equal volume. Approximately 24 h later, rats were administered a second free-swim probe trial to assess retention of spatial bias. All age/drug groups exhibited a spatial bias on the acquisition probe, with adults generally outperforming the aged rats. On the retention probe, this spatial bias continued to be shown by adult rats, regardless of treatment. For the aged group, in contrast, only MK-801-injected rats maintained a spatial bias on the retention probe, suggesting that NMDAR activity may be involved in rapid forgetting during aging. Because blockade of NMDARs also may impair new learning, which may, in turn, protect previously stored information from retroactive interference, rats in a second experiment received post-training injections of scopolamine (0.05 mg/kg), a compound known to inhibit learning. However, scopolamine did not enhance retention in the aged group, consistent with the hypothesis that MK-801 influenced memory in aged rats through its actions on NMDAR-dependent synaptic plasticity.     

Measuring Time Costs in Interventions Designed to Reduce Behavior Problems Among Children and Youth

The economic evaluation of psychosocial interventions is a growing area of research. Though time costs are central to the economist's understanding of social costs, these costs generally have been ignored by prevention scientists. This article highlights the need to measure such costs and then reviews the principles economists use in valuing time. It then considers the specific time costs that often arise in interventions designed to reduce behavior problems among children and youth. These include classroom time devoted to program activities, the time of parents or other caregivers, the time of teachers (outside of the classroom), and the time of volunteers. We consider the economic principles that govern how economists value these inputs and then apply these principles to data from an evaluation of a prominent intervention in the field, the Incredible Years Program. We find that the time costs are potentially rather large and consider the implications for public policy of ignoring them.     

A Review of Childrearing in African American Single Mother Families: The Relevance of a Coparenting Framework

Clinical research on African American single mother families has focused largely on mother-child dyads, with relatively less empirical attention to the roles of other adults or family members who often assist with childrearing. This narrow definition of “family” fails to take into account the extended family networks which often provide support for African American single mother families and the influence of these other adults on maternal parenting and youth adjustment. Our review integrates the literature on the role of extended family members, highlights the strengths and limitations of this work, and proposes the use of theory and methods from the coparenting literature to guide future study in this area. The relevance of the study of coparenting for family-based intervention efforts targeting African American youth from single mother homes is addressed.     

Amnesia,rehearsal, and temporal distinctiveness models of recall

Classical amnesia involves selective memory impairment for temporally distant items in free recall (impaired primacy) together with relative preservation of memory for recency items. This abnormal serial position curve is traditionally taken as evidence for a distinction between different memory processes, with amnesia being associated with selectively impaired long-term memory. However recent accounts of normal serial position curves have emphasized the importance of rehearsal processes in giving rise to primacy effects and have suggested that a single temporal distinctiveness mechanism can account for both primacy and recency effects when rehearsal is considered. Here we explore the pattern of strategic rehearsal in a patient with very severe amnesia. When the patient’s rehearsal pattern is taken into account, a temporal distinctiveness model can account for the serial position curve in both amnesic and control free recall. The results are taken as consistent with temporal distinctiveness models of free recall, and they motivate an emphasis on rehearsal patterns in understanding amnesic deficits in free recall.     

Establishing and maintaining an operant research facility with brushtail possums (Trichosurus vulpecula)

The common brushtail possum (Trichosurus vulpecula) is a readily accessible marsupial that has been shown to adapt relatively well to captivity. The aim of this paper is to outline the husbandry procedures, experimental equipment, and methodologies used successfully within our possum colony since 1995.     

A 40‐Year Review of Multicultural Counseling Outcome Research: Outlining a Future Research Agenda for the Multicultural Counseling Movement

This study represents a 40‐year review of multicultural counseling outcome research that has been done in the mental health professions. Particular attention is directed to the outcomes that ensue from counseling situations that are composed of counselors and clients from different racial/cultural backgrounds and identities in individual, group, and family counseling settings. Recommendations are presented for the next decade of multicultural counseling outcome research.     

Transitions in Visual Proprioception: A Cross-Sectional Developmental Study of the Effect of Visual Flow on Postural Control

In the present study, a moving room paradigm was used that characterized the developmental progression of the effects of visual perturbations on stance control in subjects (N = 39) from 5 months to 10 years of age. Kinematic (probability of recording sway, magnitude of sway response) and electromyographic (probability and patterns of muscle activation, muscle onset latencies) data were found that suggested that visual flow simulating sway activates organized postural muscle responses and results in subsequent sway in standing infants as young as 5 months of age, well before they are able to stand independently. In new walkers, there was an increase in the magnitude of the effect of the visual perturbation, suggesting a possible increase in reliance on visual information. The magnitude of sway decreased to very low levels in older children and adults. The large-amplitude responses observed in the youngest age groups may indicate an inability to switch from an unreliable to a reliable source of perceptual information or an inability to modulate the responses produced following the perturbations. With increasing age and experience, the ability to resolve the conflict increased, with adult subjects demonstrating little sway response.