Not "just" a coincidence: frontal-striatal interactions in working memory and interval timing

The frontal cortex and basal ganglia play central roles in working memory and in the ability to time brief intervals. We outline recent theoretical and empirical work to suggest that working memory and interval timing rely not only on the same anatomic structures, but also on the same neural representation of a specific stimulus. Specifically, cortical neurons may fire in an oscillatory fashion to form representations of stimuli, and the striatum (a basal ganglia structure) may detect those patterns of cortical firing that occur co-incident to important events. Information about stimulus identity can be extracted from which cortical neurons are involved in the representation, and information about duration can be extracted from their relative phase. The principles derived from these biologically based models also fit well with a family of behaviourally based models that emphasise the importance of time in many working memory phenomena.     

Size scaling: retinal or environmental frame of reference?

Previous studies have reported that when subjects are presented with two forms in a same-different task, their reaction times increase with the size ratio. This suggests a "mental scaling" transformation analogous to the "mental rotation" used to compensate for differently oriented forms in similar tasks. However, since the stimuli were presented in isolation, retinal and environmental size ratios were confounded. The present study varied both retinal and environmental size ratios in a same-different simultaneous matching task. In one experiment, random forms were placed at different distances along a textured hallway. A second experiment varied the monocular size information: In one condition the forms were displayed in a textured hallway; a second condition added cast shadows; and a third condition displayed the forms against a frontal wall of indeterminate distance. The results suggest that environmental size is determined prior to mental scaling and form matching.     

A visual equalization strategy for locomotor control: of honeybees,robots, and humans

Honeybees fly down the center of a corridor by equating the speed of optic flow in the lateral field of the two eyes. This flow-equalization strategy has been successfully implemented in mobile robots to guide behavior in cluttered environments. We investigated whether humans use a similar strategy to steer down a corridor, and determined the relative contributions of equating the speed of flow (.27), the splay angles of base lines (.62), and the visual angles of texture on the left and right walls (.03) to steering behavior. A generalized equalization strategy based on the weighted linear combination of these variables closely models human behavior, providing robust visual control.     

A case of thalamic aphasia with postmortem verification

This study discusses a case of aphasia after dominant thalamic lesion, a hemorrhagic infarction. Unlike other such cases, both repeated standardized assessment and postmortem verification were available. The patient was assessed at 3 weeks and again at 9 weeks postonset. The aphasia demonstrated the syndrome common to dominant thalamic hemorrhage: fluent but paraphasic output sometimes deteriorating to jargon, comprehension less impaired than this type of output usually indicates, and the least impairment in repetition. As sometimes reported in previous cases, semantic paraphasias were more common than phonemic paraphasias. The lesion was located in the dorsal aspect of the lateral nucleus, but it extended into the pulvinar, including the anterior superior lateral aspect which has been implicated in language by previous studies. Thus, data from this case are consistent with an involvement of the dominant pulvinar in language and suggest that this role involves the semantic aspects of language.     

Millennials and the World of Work: The Impact of Obesity on Health and Productivity

Purpose  

Thirty states now report one in three children between 10–17 years of age are either overweight or obese. This disturbing trend will have lasting implications for our children, specifically those known as the Millennial generation born between 1982 and 1993.     

A Web-Based Survey of the Relationship Between Buddhist Religious Practices,Health, and Psychological Characteristics: Research Methods and Preliminary Results

A Web-based survey was conducted to study the religious and health practices, medical history and psychological characteristics among Buddhist practitioners. This report describes the development, advertisement, administration and preliminary results of the survey. Over 1200 Buddhist practitioners responded. Electronic advertisements were the most effective means of recruiting participants. Survey participants were mostly well educated with high incomes and white. Participants engaged in Buddhist practices such as meditation, attending meetings and obtaining instruction from a monk or nun, and practiced healthful behaviors such as regular physical activity and not smoking. Buddhist meditative practice was related to psychological mindfulness and general health.     

Examining interrelationships between the Cigarette Purchase Task and delay discounting among pregnant women

Two common behavioral economic simulation tasks used to study cigarette smoking are the Cigarette Purchase Task, a measure of cigarette demand, and delay discounting, a measure of the subjective value of rewards as a function of delays to delivery. Few studies have evaluated whether combining these tasks enhances understanding of smoking beyond either alone. The current study represents an initial evaluation of the intersection between cigarette demand indices and delay discounting among pregnant smokers by examining associations between these measures and whether a woman makes antepartum quit attempts before entering prenatal care (a reliable predictor of eventual quitting). Participants were 159 pregnant women enrolled in a smoking‐cessation trial. Low O _max and shallow discounting were each associated with antepartum quit attempts. Participants were next categorized into four subgroups (low O _max, shallow discounting; low O _max, steep discounting; high O _max, shallow discounting; high O _max, steep discounting) using median splits. Those with shallow discounting and low O _max were more likely to have made quit attempts than each of the other three subgroups. That is, steep discounting appears to undermine the association of low O _max and efforts to quit smoking during pregnancy while high O _max overshadows any protective influence associated with shallow discounting.     

An overview of Bayesian reasoning in the analysis of delay‐discounting data

Statistical inference (including interval estimation and model selection) is increasingly used in the analysis of behavioral data. As with many other fields, statistical approaches for these analyses traditionally use classical (i.e., frequentist) methods. Interpreting classical intervals and p‐values correctly can be burdensome and counterintuitive. By contrast, Bayesian methods treat data, parameters, and hypotheses as random quantities and use rules of conditional probability to produce direct probabilistic statements about models and parameters given observed study data. In this work, we reanalyze two data sets using Bayesian procedures. We precede the analyses with an overview of the Bayesian paradigm. The first study reanalyzes data from a recent study of controls, heavy smokers, and individuals with alcohol and/or cocaine substance use disorder, and focuses on Bayesian hypothesis testing for covariates and interval estimation for discounting rates among various substance use disorder profiles. The second example analyzes hypothetical environmental delay‐discounting data. This example focuses on using historical data to establish prior distributions for parameters while allowing subjective expert opinion to govern the prior distribution on model preference. We review the subjective nature of specifying Bayesian prior distributions but also review established methods to standardize the generation of priors and remove subjective influence while still taking advantage of the interpretive advantages of Bayesian analyses. We present the Bayesian approach as an alternative paradigm for statistical inference and discuss its strengths and weaknesses.     

The Viability of Organizational Wellness Programs: An Examination of Promotion and Results

Wellness programs in contemporary organizations are increasing in number, but attendance is low and results often are difficult to track. We examined participant and program characteristics in 2 organizations that offered extensive wellness activities. One organization considered its program successful and had been in operation for 10 years, while the other organization's program ran for 2 years and ended because of a lack of funding. In the successful program, wellness program attendance showed a relationship to time employees took off for sick days, and improved fitness produced similar results. In the less successful operation, interviews were held with mangers and employees regarding promotion and program support. Suggestions are provided for future wellness programs.     

Evaluation of a Congressionally Mandated Wraparound Demonstration

In order to determine whether expenditures for mental health could be reduced and quality improved, Congress mandated that the Department of Defense conduct a demonstration project utilizing a wraparound mental health service system for child and adolescent military dependents. A longitudinal quasiexperimental design was used to evaluate the cost-effectiveness of the demonstration. The results showed that children in the Wraparound Group received more wraparound services than those in the treatment as usual (TAU) Comparison Group. These services included case management, in-home treatment, and other nontraditional services. The Demonstration also provided better continuity of care. Multiple methods were used to investigate the impact of wraparound. Both groups showed some improvement on some measures but there were no differences between the groups in functioning, symptoms, life satisfaction, positive functioning, or sentinel events. Regardless of which statistical model was used to estimate costs, the Demonstration was also more expensive. The higher level of expenditures for the Wraparound group was a result of some expensive traditional care and the addition of nontraditional services. Several possible explanations of these results are provided.