Within-session delay-of-reinforcement gradients

Within-session delay-of-reinforcement gradients were generated with pigeons by progressively increasing delays to reinforcement within each session. In Experiment 1, the effects of imposing progressive delays on variable-interval and fixed-interval schedules were investigated while controlling for simultaneous decreases in reinforcer rate across the session via a within-subject yoked-control procedure. Rate of key pecking decreased as a negatively decelerated function of delay of reinforcement within a session. These rate decreases were greater than those during a yoked-interval session in which the rate of immediate reinforcement decreased at the same rate as it did under the progressive-delay procedure. In Experiment 2, delay-of-reinforcement gradients were shallower when the progressive delay intervals were signaled by a blackout than when they were unsignaled. The delay gradients obtained in each experiment were similar to those generated under conditions in which different delays of reinforcement are imposed across blocks of sessions. The present procedure offers a technique for rapidly generating delay-of-reinforcement gradients that might serve as baselines for assessing the effects of other behavioral and pharmacological variables.     

Temporal variation in Irish suicide rates

Using Irish suicide data for the period 1990-1998, the independent effects of month and day adjusting for age, gender, and calendar year effects and distinguishing between holiday and working Mondays were assessed. The male suicide rate was significantly higher on working Mondays (+31%) and Saturdays (+14%), and during April, June, and August (+17%), after adjustment for the other variables. In contrast, female suicide rates were higher only in August (+35%) and exhibited no day effect. Teenage men had a greater elevation of risk on Saturdays, Sundays, and both working and holiday Mondays than any other group. The study findings should be taken into account in the planning of specialized health care services and helplines for suicidal people. Furthermore, the findings provide support for Gabennesch's (1988) broken promise theory and the relationship between dysfunctions of the serotonergic system and suicidal behavior.     

Uptake of Breast Screening is Influenced by Current Religion and Religion of Upbringing

Research has shown that individuals with a current religious affiliation are more likely to use preventive health services. The aim of this study was to determine whether breast screening uptake in Northern Ireland is higher amongst women with a current affiliation to an organised religion and, for those with no current affiliation, to examine whether their religion of upbringing is associated with uptake of breast screening. The Northern Ireland Longitudinal Study (NILS) was used to link Census and national breast screening data for 37,211 women invited for routine breast screening between 2001 and 2004. Current religious affiliation, religion of upbringing and other demographic and socio-economic characteristics were as defined on the Census form. Multivariate logistic regression was used to determine the relationship between religion affiliation and attendance. Uptake of breast screening is about 25% lower for those without a current religious affiliation. There are modest differences between Catholics and Protestants, with the latter about 11% more likely to attend for screening. For those with no current religion, the religion of upbringing appears to positively influence attendance rates. These differences remain after adjustment for all of the socio-demographic and socio-economic factors that have been shown to influence uptake rates of breast screening in the UK to date. Record linkage is an efficient way to examine equity across demographic characteristics that are not routinely available. The lower uptake amongst those with no religious affiliation may mean that screening services may find it difficult to maintain or improve uptake rate in an increasingly secularised society.     

Books Received From August 1, 2010 to July 31, 2011

Word learning is a lifelong activity constrained by cognitive biases that people possess at particular points in development. Age of acquisition (AoA) is a psycholinguistic variable that may prove useful toward gauging the relative weighting of different phonological, semantic, and morphological factors at different phases of language acquisition and development. Our aim here was to evaluate AoA as a statistical tool for taking “snapshots” of cognitive development. We examined a large corpus of English nouns (n = 1,381) with AoA as the outcome variable in three separate multivariate regressions, encompassing different age ranges (early–middle–late). Predictors included perceptual (e.g., imagery), phonological (e.g., phonological neighborhood density), and lexical (e.g., word length) factors. Different combinations of predictors accounted for significant proportions of the variance for different AoA ranges (i.e., early–middle–late). For example, imageability and frequency are stronger predictors of early relative to late word learning. These corpus analyses support a hybrid model of word learning in which multiple perceptual and linguistic factors are differentially weighted over time. This statistical approach may provide independent corroboration of and motivation for experimental studies in language learning and cognitive development.     

Citizen Involvement & Quality of Life: Exit, Voice and Loyalty in a Time of Direct Democracy

This paper explores the connection between quality of life and direct democracy. Using state level data for participation and quality of life, we find that those states with a high quality of life see higher participation in direct democracy than those with lower quality of life. However, the passage of direct democracy measures has the inverse relationship indicating the importance of maintaining the status quo for states with higher quality of life measurements.     

Response persistence under ratio and interval reinforcement schedules

In Experiment 1, rats were exposed to progressive-ratio schedules of food reinforcement while other rats were exposed simultaneously to yoked-interval schedules that arranged equivalent interreinforcer intervals but required only a single response at the end of the interval for food delivery. In Experiment 2, a within-subject yoked-control procedure was employed in which pigeons were exposed to alternating sessions (one per day) of progressive-ratio schedules and yoked-interval schedules as described above. In both experiments, responding under the yoked-interval schedule persisted beyond the point at which responding under the progressive-ratio schedule had ceased. The progressive-ratio schedules controlled break-and-run distributions, and the yoked-interval schedules controlled more even distributions of responses in time. Response rates decreased and postreinforcement pauses increased over time within individual sessions under both schedules. The results suggest that responding maintained by interval schedules is more persistent than that maintained by ratio schedules. The limitations and implications of this conclusion are discussed in the context of other investigations of response strength and behavioral momentum.     

Team-level goal orientation: an emergent state and its relationships with team inputs,process, and outcomes

Building on recent efforts to extend the concept of goal orientation to teams, we identify team-level goal orientation as an emergent state, distinct from static trait goal orientations of team members. We reinforce this distinction by developing and testing hypotheses about team inputs, processes, and outcomes as determinants of the development of team goal orientation over time. We test our hypotheses with longitudinal data from 230 participants on 64 teams engaged in a management simulation. We find that team members’ trait goal orientations affect the team’s state goal orientation, but only in the early stages of team functioning. Team process and interim outcomes drive changes in team state goal orientation.     

Generalization of Supermarket Shopping Skills for Individuals with Mild Intellectual Disabilities Using Stimulus Equivalence Training

The Psychological Record - We developed an intervention to promote generalization in an applied community setting. The intervention was derived primarily from experimental research examining...