Deterministic and Stochastic Postural Processes: Effects of Task,Environment, and Age

Upright standing is always environmentally embedded and typically co-occurs with another (suprapostural) activity. In the present study, the authors investigate how these facts affect postural dynamics in an experiment in which younger (M age = 20.23 years, SD = 2.02 years) and older (M age = 75.26 years, SD = 4.87 years) participants performed a task of detecting letters in text or maintaining gaze within a target while standing upright in a structured or nonstructured stationary environment. They extracted the coefficients of drift (indexing attractor strength) and diffusion (indexing noise strength) from the center of pressure (COP) time series in anteroposterior (AP) and mediolateral (ML) axes. COP standard deviation decreased with drift and increased with diffusion. The authors found that structure reduced AP diffusion for both groups and that letter detection reduced younger SD _AP (primarily by diffusion decrease) and increased older SD _ML (primarily by drift decrease). For older and younger participants, ML drift was lower during letter detection. Further, in older letter detection, larger visual contrast sensitivity was associated with larger ML drift and smaller SD _ML, raising the hypotheses that ML sway helps information detection and reflects neurophysiological age.     

Studies in the Peripheral Retina: II. The Purkinje After-Image on the Near Foveal Area of the Retina

Although true second-order conditioning has, apparently, not previously been demonstrated in any American laboratory, it was found that by using electrodes implanted in the occipital sensory areas of hens, second-order limb responses could be readily established in approximately 33% of a group of 51 subjects developing first-order conditioned responses. In a number of subjects, the second-order responses remained stable for hundreds of trials and were highly resistant to extinction. Electrolytic damage at the sites of the cerebral reinforcing electrodes had no discernible effect on the stability of the second-order conditioned responses. They could also be evoked when direct current which temporally overlapped the cerebral conditioned stimuli was passed between or adjacent to the signal electrodes.     

Genetic and Environmental Variation on the California Psychological Inventory Vector Scales

Three recently introduced vector scales for the California Psychological Inventory (CPI) were scored for the National Merit Twin Sample and subjected to a heredity-environment analysis. Confidence intervals for genetic and environmental parameters were obtained by a bootstrap method. Two of the scales, Internality (Vector 1) and Self-Realization (Vector 3), showed the substantial heritability and near-zero family environment effects typically found for personality scales, whereas Norm-Favoring (Vector 2) showed an appreciable effect of family environment and a nonsignificant heritability.     

A SCIENTIFIC BUDDHISM?

This essay endorses the argument of Donald Lopez's Buddhism and Science and shows how the general thesis of the book is consonant with other historical work on the “discovery” of Buddhism and on the emergence of Western conceptions of religion. It asks whether one of the key claims of Buddhism and Science—that Buddhism pays a price for its flirtation with the modern sciences—might be applicable to science‐and‐religion discussions more generally.     

Origins of Order in Joint Activity and Social Behavior

How should we understand the origins of order and control that entail the systematic regularity of human behavior? Here, we address this question with respect to joint activity and social behavior via an explication of Guy Van Orden's formulation of interaction-dominant dynamics and his provocative discussion of the “blue collar brain.” Using these 2 concepts we argue that human social behavior and performance is not controlled by a cascade of fast timescale activity (i.e., neural processes or individual action) but rather emerges from the modulated enslavement of faster timescale processes by much slower dynamical processes, such as shared task outcomes and socially defined historical context. We detail this argument by reviewing 2 recent behavioral findings that we believe provide evidence that the dynamics of human performance during a socially situated activity is interaction dominant. The first concerns the behavioral coordination that emerges during a novel joint-action collision-avoidance task. The second concerns the effects of stereotype threat on an individual's cognitive performance. Finally, we discuss how identifying the role that the slower timescale dynamics of social events and structures plays in shaping complex behavioral dynamics can guide future research on joint-action and human performance.     

Do peers make the place? Conceptual synthesis and meta-analysis of coworker effects on perceptions, attitudes, OCBs, and performance

The authors propose that broad aspects of lateral relationships, conceptualized as coworker support and coworker antagonism, are linked to important individual employee outcomes (role perceptions, work attitudes, withdrawal, and effectiveness) in a framework that synthesizes several theoretical predictions. From meta-analytic tests based on 161 independent samples and 77,954 employees, the authors find support for most of the proposed linkages. Alternative explanations are ruled out, as results hold when controlling for leader influences and mediation processes. The authors also observe differential strengths of coworker influence based on its valence, content, and severity, and on the social intensity of the task environment. The authors conclude with a call for more comprehensive, complex theory and investigation of coworker influences as part of the social environment at work. (PsycINFO Database Record (c) 2008 APA, all rights reserved).     

Differential role of the hippocampus in response-outcome and context-outcome learning: evidence from selective satiation procedures

Instrumental performance in rats with hippocampal lesions is insensitive to the degradation of action-outcome contingencies, but sensitive to the effects of selective devaluation by satiation. One interpretation of this dissociation is that damage to the hippocampus impairs the formation of context-outcome associations upon which the effect of contingency degradation, but not selective satiation, relies. Here, we provide a direct assessment of this interpretation, and showed that conditioned responding to contexts did not show sensitivity to selective satiation (Experiment 1), and confirmed that instrumental performance was sensitive to selective satiation (Experiment 2) following hippocampal cell loss.