Rapid acquisition of choice and timing and the provenance of the terminal-link effect

Eight pigeons responded in a concurrent-chains procedure in which terminal-link schedules changed pseudorandomly across sessions. Pairs of terminal-link delays either summed to 15 s or to 45 s. Across sessions, the location of the shorter terminal link changed according to a pseudorandom binary sequence. On some terminal links, food was withheld to obtain start and stop times, measures of temporal control. Log initial-link response ratios stabilized within the first half of each session. Log response ratio was a monotonically-increasing but nonlinear function of programmed log terminal-link immediacy ratio. There was an effect of absolute terminal-link duration on log response ratio: For most subjects, preference for the relatively shorter terminal-link delay was stronger when absolute delays were long than when absolute delays were short. Polynomial regressions and model comparison showed that differences in degree of nonlinearity, not in sensitivity to log immediacy ratio, produced this effect. Temporal control of stop times was timescale invariant with scalar variability, but temporal control of start times was not consistent across subjects or terminal-link durations.     

Collaboration with Urban Community Stakeholders: Refining Paraprofessional‐led Services to Promote Positive Parenting

This paper describes the process of a community–academic partnership to navigate implementation challenges for a school‐based service model led by paraprofessionals to promote positive parenting in high poverty urban communities. We describe the process by which we (a) identified implementation challenges, (b) sustained a university–community collaboration to redesign the paraprofessional service model, and (c) assessed the feasibility of the new model involving four social service agencies in 16 schools with over 600 families. The structure and process of the collaboration and refinement are described with attention to who was best positioned to engage in the collaboration and how the partnership worked to balance scientific rigor with responsiveness to paraprofessional workforce strengths. Feasibility data indicated that the revised model was successfully implemented by paraprofessional staff; 92.2% of possible staff monthly reports were completed and discussion of key goals was incorporated into 94.2% of interactions. Continual monitoring provided critical feedback from stakeholders as we drew on and interpreted these various sources of information to build and refine the service model. We suggest that these processes are critical steps to bridge the research‐to‐practice gap, by promoting practices that are aligned with the needs of children and families, and the staff who serve them.     

Rapid acquisition of preference in concurrent chains: effects of d-amphetamine on sensitivity to reinforcement delay

The purpose of this study was to examine effects of d-amphetamine on choice controlled by reinforcement delay. Eight pigeons responded under a concurrent-chains procedure in which one terminal-link schedule was always fixed-interval 8 s, and the other terminal-link schedule changed from session to session between fixed-interval 4 s and fixed-interval 16 s according to a 31-step pseudorandom binary sequence. After sufficient exposure to these contingencies (at least once through the pseudorandom binary sequence), the pigeons acquired a preference for the shorter reinforcement delay within each session. Estimates of the sensitivity to reinforcement immediacy were similar to those obtained in previous studies. For all pigeons, at least one dose of d-amphetamine attenuated preference and, hence, decreased estimates of sensitivity to reinforcement immediacy; in most cases, this effect occurred without a change in overall response rates. In many cases, the reduced sensitivity to reinforcement delay produced by d-amphetamine resulted primarily from a decrease in the asymptotic level of preference achieved within the session; in some cases, d-amphetamine produced complete indifference. These findings suggest that a reduction in the sensitivity to reinforcement delay may be an important behavioral mechanism of the effects of psychomotor stimulants.     

The BAI–PC as a Screen for Anxiety, Depression, and PTSD in Primary Care

Despite the prevalence of psychiatric disorders in medical settings, mental health problems often go undetected and patients do not receive appropriate treatment. The main goal of this study is to provide additional information about the Beck Anxiety Inventory – Primary Care (BAI–PC), a brief instrument that screens for patients with anxiety. This study provides information on the performance of the BAI–PC as a screening instrument for depression and PTSD in addition to its original purpose as a screening instrument for anxiety. This efficient tool can identify patients who can benefit from effective psychological treatments and facilitate referrals to psychologists working in medical settings.     

Mathematics self-efficacy: stereotype threat versus resilience

Children’s academic self-efficacy is one of the strongest predictors of achievement (Wigfield and Eccles, Contemporary Educational Psychology 25(1): 68–81, 2000). The present research examined mathematics self-efficacy and the relationship of racial context from the perspective of two competing bodies of research. Stereotype threat theory would predict that, under conditions where negative stereotypes are salient, self-efficacy would decrease. So, Black/African American students in primarily White classrooms would be predicted to report lower self-efficacy. However, other research suggests that Black/African American students demonstrate fortitude even under disadvantage (e.g., Graham, Review of Educational Research, 64(1): 55–117, 1994). We examined the mathematics self-efficacy of 170 fifth-grade students. In contrast to stereotype threat theory, results suggested that Black/African American students’ self-efficacy remained stable regardless of the racial breakdown of the class. However, White students demonstrated elevated self-efficacy when in predominantly Black/African American classrooms. These results could not be explained by differences in classroom environments. Results are discussed in terms of resilience, ethnic identity and White identity.     

A contextual model of concurrent-chains choice

An extension of the generalized matching law incorporating context effects on terminal-link sensitivity is proposed as a quantitative model of behavior under concurrent chains. The contextual choice model makes many of the same qualitative predictions as the delay-reduction hypothesis, and assumes that the crucial contextual variable in concurrent chains is the ratio of average times spent, per reinforcement, in the terminal and initial links; this ratio controls differential effectiveness of terminal-link stimuli as conditioned reinforcers. Ninety-two concurrent-chains data sets from 19 published studies were fitted to the model. Averaged across all studies, the model accounted for 90% of the variance in pigeons' relative initial-link responding. The model therefore demonstrates that a matching law analysis of concurrent chains—the assumption that relative initial-link responding equals relative terminal-link value—remains quantitatively viable. Because the model reduces to the generalized matching law when terminal-link duration is zero, it provides a quantitative integration of concurrent schedules and concurrent chains.     

Characteristics of 12th-grade students seriously deficient in spatial ability

When spatial ability was regressed on a measure of general intelligence in a large national sample of 12th-graders, there was a distinct downturn in the regression line at about -2 SD units. A bimodal distribution of spatial ability was found among these low scoring students, suggesting 2 qualitatively different types of individuals. Relative to students of expected spatial ability, those below expected in spatial ability were high on verbal skills and low on performance skills. Students unexpectedly low in spatial ability performed relatively well on cognitive tests that required answering unambiguous questions by retrieving information directly from long term memory, whereas they performed relatively poorly on tests requiring inference and perception of relations among novel stimuli. Students unexpectedly low in spatial ability performed especially poorly at tests involving visual-spatial perception skills. Results were similar for both sexes. The relatively poor performance of those unexpectedly low in spatial ability does not appear to be related to health problems, personality, interest differences, or biographical data. An organic impairment possibly related to lateralization represents a reasonable causal hypothesis for these data.     

On the relation between preference and resistance to change

Nevin (1979) noted that preference in concurrent chains and resistance to change in multiple schedules were correlated, in that both measures were affected similarly by variations in parameters of reinforcement such as rate, immediacy, and magnitude. To investigate the relationship between preference and resistance to change directly, we used a within-session procedure that arranged concurrent chains in one half of the session and a multiple schedule in the other half. The same variable-interval schedules served as terminal links in concurrent chains and as the components of the multiple schedule, and were signaled by the same stimuli. After performances had stabilized, responding in the multiple schedule was disrupted by delivering response-independent reinforcement during the blackout periods between components. Both preference in concurrent chains and relative resistance to change of multiple-schedule responding were well described as power functions of relative reinforcement rate, as predicted by current quantitative models (Grace, 1994; Nevin, 1992b). In addition, unsystematic variation in preference and resistance to change was positively correlated, which suggests that preference and resistance to change are independent measures of a single construct. That construct could be described as the learning that occurs regarding the prevailing conditions of reinforcement in a distinctive stimulus situation.