AX+/BX- discrimination learning in the fear-potentiated startle paradigm in monkeys

Individuals with anxiety disorders often do not respond to safety signals and hence continue to be afraid and anxious. Consequently, it is important to develop paradigms in animals that can directly study brain systems involved in learning about, and responding to, safety signals. We previously developed a discrimination procedure in rats of the form AX+/BX-, where cues A and X presented together are paired with an aversive stimulus and cues B and X presented together predict the absence of an aversive stimulus. The present experiment adapted this procedure to the fear-potentiated startle paradigm in rhesus monkeys.     

A theory-based approach to teaching young children about health: A recipe for understanding

The theory-theory account of conceptual development posits that children's concepts are integrated into theories. Concept learning studies have documented the central role that theories play in children's learning of experimenter-defined categories, but have yet to extensively examine complex, real-world concepts such as health. The present study examined whether providing young children with coherent and causally-related information in a theory-based lesson would facilitate their learning about the concept of health. This study used a pre-test/lesson/post-test design, plus a five month follow-up. Children were randomly assigned to one of three conditions: theory (i.e., 20 children received a theory-based lesson); nontheory (i.e., 20 children received a nontheory-based lesson); and control (i.e., 20 children received no lesson). Overall, the results showed that children in the theory condition had a more accurate conception of health than children in the nontheory and control conditions, suggesting the importance of theories in children's learning of complex, real-world concepts.     

Locomotor strategies in response to altered lower limb segmental mechanical properties

The present study sought to use stilt walking as a model to uncover modifications to gait dynamics caused by changes in lower limb anthropometrics. We examined 10 novice and 10 expert stilt walkers, each walking with and without stilts, to determine the specific adaptations brought about by experience. Three-dimensional kinematics and force platform data were used to calculate the intersegmental forces, net joint moments and moment powers at the ankle, knee and hip. Spatio-temporal data were computed to aid the interpretation of these data. Non-dimensional scaling was used to facilitate comparison between stilt- and normal-walking. In general, the stilts induced largely the same alterations in the locomotor patterns of both novices and experts, which did not allow for the conclusion that the experts employed locomotor dynamics that were better suited to the challenges imposed by alterations to limb length, mass and mass moment of inertia induced by the stilts. Nevertheless, the experts exhibited a lesser reduction in dimensionless stride length and velocity and generated larger concentric knee flexor and hip extensor powers, relative to the novices, which may be indicative of enhanced dynamic stability control.     

Managerial Support for Dual-Career Relocation Dilemmas

This study examined managerial decision making in the context of a dual-career relocation dilemma. Specifically, 143 managers and professionals responded to a memo contained in an in-basket simulation exercise that involved a dual-career employee relocation and corresponding request for spouse employment assistance. Competing theoretical predictions were tested with regard to managerial support for this dual-career work-family situation as a function of the gender of the employee. Findings indicated that managers offered more extensive assistance to the spouse of a female employee than to the spouse of a male employee. A content analysis of decision-makers' responses indicated a wide range of specific responses, with offering multiple forms of assistance being most common (27%), followed by delegating the issue to human resources (22%). The results are discussed in terms of implications for future research on managerial support for work-family and employee mobility. Practical suggestions are outlined.     

A normative zone of RPE ratings for use during graded exercise testing

The purposes of this investigation were to identify a zone of normality for ratings of perceived exertion (RPE) and to compare the RPE responses in patients with coronary artery disease to this zone. The zone was generated from RPE estimated during the last minute of each stage of a Bruce treadmill test in 44 normal adult men. RPE were regressed against the corresponding MET level for each exercise stage. The zone was established as the 95% confidence interval (CI) spanning the average RPE vs MET regression line. RPE estimated during the last 1.0 min. of a Bruce or Modified Balke treadmill test administered to adult men (n=37) with coronary artery disease were compared to the 95% CI zone. A total of 19 (51%) of the coronary artery disease patients estimated RPE during a progressively incremented treadmill test that were above the zone, indicating a comparatively greater than normal perception of strain for a given metabolic stress. The presently generated zone provides a practical use of RPE in the interpretation of clinical exercise tests.     

Socioeconomic gradients predict individual differences in neurocognitive abilities

Socioeconomic status (SES) is associated with childhood cognitive achievement. In previous research we found that this association shows neural specificity; specifically we found that groups of low and middle SES children differed disproportionately in perisylvian/language and prefrontal/executive abilities relative to other neurocognitive abilities. Here we address several new questions: To what extent does this disparity between groups reflect a gradient of SES‐related individual differences in neurocognitive development, as opposed to a more categorical difference? What other neurocognitive systems differ across individuals as a function of SES? Does linguistic ability mediate SES differences in other systems? And how do specific prefrontal/executive subsystems vary with SES? One hundred and fifty healthy, socioeconomically diverse first‐graders were administered tasks tapping language, visuospatial skills, memory, working memory, cognitive control, and reward processing. SES explained over 30% of the variance in language, and a smaller but highly significant portion of the variance in most other systems. Statistically mediating factors and possible interventional approaches are discussed.