Influence of delayed muscle reflexes on spinal stability: Model-based predictions allow alternative interpretations of experimental data

Model-based calculations indicate that reflex delay and reflex gain are both important for spinal stability. Experimental results demonstrate that chronic low back pain is associated with delayed muscle reflex responses of trunk muscles. The aim of the present study was to analyze the influence of such time-delayed reflexes on the stability using a simple biomechanical model. Additionally, we compared the model-based predictions with experimental data from chronic low back pain patients and healthy controls using surface-electromyography. Linear stability methods were applied to the musculoskeletal model, which was extended with a time-delayed reflex model. Lateral external perturbations were simulated around equilibrium to investigate the effects of reflex delay and gain on the stability of the human lumbar spine. The model simulations predicted that increased reflex delays require a reduction of the reflex gain to avoid spinal instability. The experimental data support this dependence for the investigated abdominal muscles in chronic low back pain patients and healthy control subjects. Reflex time-delay and gain dependence showed that a delayed reflex latency could have relevant influence on spinal stability, if subjects do not adapt their reflex amplitudes. Based on the model and the experimental results, the relationship between muscle reflex response latency and the maximum of the reflex amplitude should be considered for evaluation of (patho) physiological data. We recommend that training procedures should focus on speeding up the delayed reflex response as well as on increasing the amplitude of these reflexes.     

Multiplicity of marital adjustment ratings: A Suggestion

Abstract

Recent discussions of “reality” will be argued as having failed to differentiate clearly between two levels: the level of things, people and events that can, for most purposes, reasonably be taken as existing “out there”; and the level of the meanings that can be applied to them by an observer. An anarchistic approach will be recommended.     

Entrevista con Jean-Paul Bronckart

RESUMEN

Bronckart comienza revisando su trayectoria científica y explicando cuáles son sus dos enfoques básicos: el análisis del contexto o de situaciones y el análisis del lenguaje en función de sus operaciones subyacentes definidas en el marco de las teorías de la enunciación. Seguidamente justifica su renuncia a posiciones estructuralistas porque no tienen en cuenta el problema de las relaciones funcionales ni prestan atención al contexto. El autor relaciona las operaciones psicológicas con universales funcionales diferenciándolos de los estructurales de Chomsky y del enfoque de Searle, defendiendo su interés por la lingüística comparativa. Seguidamente aborda el tema de análisis de textos en ambientes escolares, sugiriendo que hay que sensibilizar a los educadores sobre el hecho de que constantemente estamos en situaciones de comunicación que van cambiando y crear instrumentos para que puedan analizar su propia práctica. Con relación al aspecto cognitivo del lenguaje, enfatiza la proliferación excesiva de los enfoques representativos y seguidamente desarrolla qué entiende por especificidad de la naturaleza del lenguaje y de su carácter comunicativo. Esta entrevista aborda, además, cuestiones tales como el fenómeno presuposicional, las aportaciones de Vygotsky o las experiencias de enseñar lenguaje a chimpancés, y finaliza planteando algunos aspectos de la teoría de Culioli.     

“Drive On”: The Relationship Between Psychological Variables and Effective Squad Leadership

The U.S. Reserve Officer Training Program (ROTC) conducts systematic assessments of cadets’ leadership abilities during field training exercises (FTX) to assess their leadership abilities. While cadets in ROTC programs learn specific tactical operation procedures to augment FTX performances, much less is known about the relationship between psychological variables and squad leadership performance. To this end, 220 cadets completed self-efficacy, psychological flexibility, and grit questionnaires, which were then compared to FTX performance scores. Results underscored that only self-efficacy was significantly related to cadets’ squad leadership ability. Furthermore, prior service in the U.S. Army had no effect on the performance score one attained, highlighting an interesting paradox. Therefore, while self-efficacy can be cultivated through prior experiences, it seems more prudent to educate ROTC cadets on how to apply psychological skills to bolster self-efficacy in preparation for upcoming challenging leadership experiences.     

Improving Classroom Quality with The RULER Approach to Social and Emotional Learning: Proximal and Distal Outcomes

The RULER Approach to Social and Emotional Learning (“RULER”) is designed to improve the quality of classroom interactions through professional development and classroom curricula that infuse emotional literacy instruction into teaching–learning interactions. Its theory of change specifies that RULER first shifts the emotional qualities of classrooms, which are then followed, over time, by improvements in classroom organization and instructional support. A 2-year, cluster randomized controlled trial was conducted to test hypotheses derived from this theory. Sixty-two urban schools either integrated RULER into fifth- and sixth-grade English language arts (ELA) classrooms or served as comparison schools, using their standard ELA curriculum only. Results from multilevel modeling with baseline adjustments and structural equation modeling support RULER’s theory of change. Compared to classrooms in comparison schools, classrooms in RULER schools exhibited greater emotional support, better classroom organization, and more instructional support at the end of the second year of program delivery. Improvements in classroom organization and instructional support at the end of Year 2 were partially explained by RULER’s impacts on classroom emotional support at the end of Year 1. These findings highlight the important contribution of emotional literacy training and development in creating engaging, empowering, and productive learning environments.     

Neighborhood Context and Perceptions of Stress Over Time: An Ecological Model of Neighborhood Stressors and Intrapersonal and Interpersonal Resources

We examine the association between neighborhood socio-economic disadvantage and perceived stress during middle and late adolescence among African American youth (N = 665; 51 % female; M = 15.9 years at baseline). In addition, we explored the ways through which neighborhood stressors interacted with an individual’s intra- and interpersonal resources (e.g., coping, social support and substance use), to affect their perceived stress trajectories during adolescence. First, we tested a neighborhood stressors model and found that youth who lived in neighborhoods with greater socioeconomic disadvantage had higher baseline stress and a steeper increase in stress over time. When we included individual-level risk and promotive factors in the model, however, the effect of neighborhood disadvantage on perceived stress was no longer significant, and the stress trajectory was explained by adolescent substance use, social support and perceptions of the neighborhood. Our results support theories of stress and coping, and the importance of proximal intra- and interpersonal factors in either amplifying or mitigating perceptions of stress. We discuss implications of the neighborhood context and how our findings may inform future prevention and intervention related to adolescent stress and development.     

Categorization of two-dimensional and three-dimensional stimuli by 18-month-old infants

In two experiments, 18-month-old infants’ categorization of 3D replicas and 2D photographs of the same animals and vehicles were compared to explore infants’ flexibility in categorization across different object representations. Using a sequential touching procedure, infants completed one superordinate and two basic-level categorization tasks with 3D replicas, 2D cut out photographs, or 2D images on photo cubes (“2D cubes”). For superordinate sets, 3D replicas elicited longer mean run lengths than 2D cut outs, and 3D replicas elicited equivalent mean run lengths as 2D cubes. For basic-level sets, infants categorized high-contrast animal sets when presented with 3D replicas, but they failed to categorize any of the 2D photograph sets. Categorization processes appear to differ for 3D and 2D stimuli, and infants’ discovery of object properties over time while manipulating objects may facilitate categorization, as least at the superordinate level. These findings are discussed in the context of infants’ representation abilities and the integration of perception and action.     

What do people think about changes in health behaviors? Differential perceptions of consequences of increases and decreases in health behaviors

Most health decision-making models posit that cost-benefit analyses underlie decisions to make changes in health-related behavioral practices. In a series of studies, participants imagined either increasing or decreasing the frequency of a variety of health behaviors and estimated the consequences of those changes. In Studies 1 and 2, individuals consistently estimated that increasing a health behavior produced greater consequences than did decreasing the behavior by an equivalent amount. The results of Study 3 demonstrated that this effect is due to differences in how individuals judge the impact of health behavior changes which involve not engaging in the behavior at all versus other types of changes. Taken together, these findings suggest that perceptions of the outcomes afforded by health behavior changes depend on both the behavioral frequency and direction of changes in behavior an individual is considering. This asymmetry has the potential to help explain patterns of behavior in a range of important health domains and may impact the effectiveness of behavior change interventions.     

Quitting smoking: The importance of non-smoker identity in predicting smoking behaviour and responses to a smoking ban

Objective: We examined how ‘smoker’ and ‘non-smoker’ self- and group-identities and socio-economic status (SES) may predict smoking behaviour and responses to antismoking measures (i.e. the Dutch smoking ban in hospitality venues). We validated a measure of responses to the smoking ban.

Design: Longitudinal online survey study with one-year follow-up (N = 623 at T1 in 2011; N = 188 at T2 in 2012) among daily smokers.

Main outcome measures: Intention to quit, quit attempts and ‘rejecting’, ‘victimizing’, ‘socially conscious smoking’ and ‘active quitting’ responses to the smoking ban.

Results: Non-smoker identities are more important than smoker identities in predicting intention to quit, quit attempts and responses to the smoking ban, even when controlling for other important predictors such as nicotine dependence. Smokers with stronger non-smoker identities had stronger intentions to quit, were more likely to attempt to quit between measurements, and showed less negative and more positive responses to the smoking ban. The association between non-smoker self-identity and intention to quit was stronger among smokers with lower than higher SES.

Conclusion: Antismoking measures might be more effective if they would focus also on the identity of smokers, and help smokers to increase identification with non-smoking and non-smokers.     

Psychological intervention with couples coping with breast cancer: A systematic review

Objective: Information about psychological intervention with couples coping with breast cancer is not well-disseminated. This can be explained, at least in part, by the absence of knowledge about the efficacy of this kind of intervention. The aim of the present systematic review is to identify and describe psychological interventions for couples coping with breast cancer and evaluate their efficacy.

Design: Studies identified by a searching multiple literature databases related to health and psychology between 1975 and 2013. Rigorous inclusion and exclusion criteria were utilised.

Results: Of 129 abstracts, 13 were extracted for further analysis and a final ten studies were deemed eligible for inclusion. Data were extracted from each study regarding study sample characteristics, design, results and methodological limitations. The results obtained were mixed in regard to efficacy, although the overwhelming majority of studies (eight studies) found benefits for both women and their partners in some dimensions, such as quality of life, psychological distress, relationship functioning and physical symptoms associated with cancer.

Conclusion: Psychological interventions for couples coping with breast cancer appear to be effective for both women and their partners. However, further studies are needed to evaluate the efficacy of couple-based interventions and, to identify for whom and how they are more effective.