Advantages of Rhythmic Movements at Resonance: Minimal Active Degrees of Freedom,Minimal Noise,and Maximal Predictability

Using time delay embedding, the authors applied phase space reconstruction to the time series of rhythmic movements of a hand-held pendulum. Subjects (N = 6) produced the manual oscillations about the wrist at the pendulum's resonant frequency and at a higher and a lower frequency. The number of active degrees of freedom required to capture the dynamics of the rhythmic behavior was 3 for the resonant frequency and 4 for each of the nonresonant frequencies. The residual high-dimensional noise was similarly lowest for the resonant frequency. Whereas 33% and 20%, respectively, of the vectors in the phase spaces of the dynamics higher and lower than resonance were unpredictable, only 12% were unpredictable at resonance. Finally, the predictability of the evolving dynamics extended farther into the future for oscillations at the resonant frequency. At resonance, the prediction horizon was 5 times farther than the prediction horizon for the higher than resonance behavior and 2.5 times farther than that for the lower than resonance behavior. The results suggest that, in pendular oscillations of a limb or limb segment, attunement of the central nervous system to the resonant frequency minimizes the variables to be controlled and maximizes the predictability of the rhythmic movement's chaotic dynamics.     

Problems of dependence and development: Discussion

Abstract

Anna Freud: Normality and Pathology in Childhood. Assessments of Development. International Universities Press, Inc., New York, 1965. Pp. XII and 273.

M. L. Kellmer Pringle: Deprivation and Education. Longmans Green &; Co. Ltd., London, 1965. Pp. vi and 311. 42s. 6d.     

Discovering your inner Gibson: Reconciling action-specific and ecological approaches to perception–action

Both the action-specific perception account and the ecological approach to perception–action emphasize the role of action in perception. However, the action-specific perception account demonstrates that different percepts are possible depending on the perceiver’s ability to act, even when the same optical information is available. These findings challenge one of the fundamental claims of the ecological approach—that perception is direct—by suggesting that perception is mediated by internal processes. Here, we sought to resolve this apparent discrepancy. We contend that perception is based on the controlled detection of the information available in a global array that includes higher-order patterns defined across interoceptive and exteroceptive stimulus arrays. These higher-order patterns specify the environment in relation to the perceiver, so direct sensitivity to them would be consistent with the ecological claims that perception of the environment is direct and animal-specific. In addition, the action-specific approach provides further evidence for the theory of affordances, by demonstrating that even seemingly abstract properties of the environment, such as distance and size, are ultimately perceived in terms of an agent’s action capabilities.     

Associations between work family conflict,emotional exhaustion,musculoskeletal pain,and gastrointestinal problems in a sample of business travelers

The aim of the study was to examine the associations among work‐family conflict (WFC), emotional exhaustion, musculoskeletal (MS) pain, and gastrointestinal problems on a sample of business travelers (n = 2,093). An additional aim was to examine differences in the mentioned relationships among three traveler groups: commuters, national travelers, and international travelers. The study was conducted in a large Norwegian oil and gas company, and the company's business travel database was utilized to examine business travel. Structural equation modeling (SEM) revealed significant relations between WFC and emotional exhaustion and between emotional exhaustion and health problems. Contrary to the expectations, no direct association was found between WFC and health problems. However, we found that emotional exhaustion mediated the relation between WFC and health outcomes. The results from multi‐group analysis revealed that associations among WFC, emotional exhaustion, and health‐outcomes showed a similar pattern for commuters, national travelers, and international travelers. However, the association between emotional exhaustion and MS pain proved to be significantly stronger for the commuter group compared to the national and international travel groups. Practical implications and the consequences of these findings for future research are discussed.     

Do Equal Rights for a Minority Affect General Life Satisfaction?

While previous research examines how institutions matter for general life satisfaction and how specific institutions embodying equal rights for gay people matter for the life satisfaction of gays, we combine these two issues to analyze how the latter type of institutions relates to general life satisfaction. The question is how people in general are affected by laws treating everyone equally irrespective of sexual orientation. We find that legal recognition of partnership, marriage and adoption rights, as well as an equal age of consent, relate positively to general life satisfaction. Consequently, same-sex marriage and similar reforms come at no “welfare” cost to society at large—if anything, the opposite appears to hold. We further build on previous research showing positive effects of economic freedom on happiness and on tolerance towards gay people and interact our rights measure with economic freedom. This reveals that the positive effect on general happiness of equal rights mainly appears in countries with low economic freedom. This likely follows because minority rights are perceived to indicate openness to much-desired reforms in other areas.     

Multiplicity Within and Between: Addressing Multiple Roles Through Role Profiles in Couples

The purpose of this study is to test the validity of a personality assessment, Role Profiles, by exploring the relationship between role balance and individual well-being and the relationship between couples’ role profiles similarity and their marital satisfaction. Twenty couples were recruited and completed the assessments. This study partially supported Role Profiles’ validity and the findings were consistent with previous studies: individuals with higher role confusion were more likely to report lower self-esteem, and couples who shared many identical roles in their roles profiles were more likely to report higher marital satisfaction. The utility of Role Profiles as a clinical assessment in couples therapy is discussed.     

Explaining Murder in Maine: Three Case Studies

Research suggests that popular depictions of crime and criminals are influenced by a dominant ideology that explains crime in terms of the individual failings of criminals, while ignoring social contributions to crime rates. The research reported here, based on an ethnographic content analysis of newspaper depictions of 108 murderers, identifies and describes three case studies of criminal homicide which challenge the dominant ideology by highlighting social contributions to crime. These cases suggest that an alternative ideology which explains crime with reference to institutional processes and collective responsibility may be identified in newspaper accounts of murder in Maine.