Comparison and evaluation of two common methods to measure center of mass displacement in three dimensions during gait

Center of mass displacement during gait has frequently been used as an indicator of gait efficiency or as a complement to standard gait analysis. With technological advances, measuring the center of mass as the centroid of a multi-segment system is practical and feasible, but must first be compared to the well-established Newtonian computation of double-integrating the ground reaction force. This study aims to verify that the kinematic centroid obtained from a commonly-used model (Vicon Peak Plug-In-Gait) provides at least as reliable measurements of center of mass displacement as those obtained from the ground reaction forces. Gait data was collected for able-bodied children and children with myelomeningocele who use larger lateral center of mass excursions during gait. Reasonable agreement between methods was found in fore-aft and vertical directions, where the methods' excursions differed by an average of less than 10 mm in either direction, and the average RMS differences between methods' computed curves were 6 and 13 mm. Particularly good agreement was observed in the lateral direction, where the calculated excursions differed by an average of less than 2 mm and the RMS difference was 5 mm. Error analyses in computing the center of mass displacement from ground reaction forces were performed. A 5% deviation in mass estimation increased the computed vertical excursion twofold, and a 5% deviation in the integration constant of initial velocity increased the computed fore-aft excursions by 10%. The suitability of calculating center of mass displacement using ground reaction forces in a patient population is questioned. The kinematic centroid is susceptible to errors in segment parameters and marker placement, but results in plausible results that are at least within the range of doubt of the better-established ground reaction force integration, and are more useful when interpreting 3-D gait data.     

Adaptation of the MSCI for the measurement of cohesion in Spanish young soccer players

This work describes the Spanish adaptation and studies the psychometric properties of Yukelson, Weinberg, and Jackson's Multidimensional Sport Cohesion Instrument (MSCI) with a sample of 173 soccer players. The Spanish version is composed of 22 items grouped in four factors: quality of teamwork (performance aspects), attraction to the group, valued roles and quality of teamwork (interpersonal relationships), that accounted for 53.30% of the total variance. Reliability coefficients (Cronbach's Alphas) for the factors ranged from .84 (factor 1) to .56 (factor 4). Suggestions are made for future research on the validity of the scale, mainly in terms of convergence with other multidimensional measures of sport cohesion.     

Influence of personality on ecological consumer behaviour

• We have recently seen the appearance of many studies which attempt to discover the behaviour patterns of ecological consumers. For that reason, it seems necessary to analyse the variables that shape this consumer profile. In this study, we have focused on psychographic variables and, in particular, on personality features. Following a survey with a random sample of 573 individuals, we designed a theoretical model which included the Big‐Five Factor Structure scale and the environmental attitude dimension referred to as “actual commitment” to measure personality and ecological behaviour, respectively. We carried out several principal factor analyses in order to validate these scales and afterwards, we performed a structural equation analysis and a logit analysis. Findings support our hypotheses since they reveal that personality is a multifaceted concept, which is positively related to ecological behaviour. Firms should focus on those people who are characterised by personality features such as extroversion, agreeableness and conscientiousness in order to persuade them to demand their products.

Copyright © 2006 John Wiley & Sons, Ltd.     

Reconsolidation of a context long-term memory in the terrestrial snail requires protein synthesis

We investigated the influence of the protein synthesis blocker anisomycin on contextual memory in the terrestrial snail Helix. Prior to the training session, the behavioral responses in two contexts were similar. Two days after a session of electric shocks (5 d) in one context only, the context conditioning was observed as the significant difference of behavioral response amplitudes in two contexts. On the day following testing of context learning, a session of "reminding" was performed, immediately after which the snails were injected with anisomycin or vehicle. Testing of long-term context memory has shown that only anisomycin injections impaired the context conditioning. In control series, the snails were injected after the training session with anisomycin/saline without reminding, and no impairment of the long-term context memory was observed, while injection of anisomycin during the training session completely abolished the long-term memory. No effects of anisomycin on the short-term memory were observed. Surprisingly, injection of anisomycin after the reminding combined with reinforcing stimuli elicited no effect on the context memory. Differences between single-trial and multisession learning are discussed.     

Temporal properties of disparity processing revealed by dynamic random-dot stereograms

In studies of the temporal flexibility of the stereoscopic system, it has been suggested that two different processes of binocular depth perception could be responsible for the flexibility: tolerance for interocular delays and temporal integration of correlation. None has investigated the relationship between tolerance for delays and temporal integration mechanisms and none has revealed which mechanism is responsible for depth perception in dynamic random-dot stereograms. We address these questions in the present study. Across five experiments, we investigated the temporal properties of stereopsis by varying interocular correlation as a function of time in controlled ways. We presented different types of dynamic random-dot stereograms, each consisting of two pairs of alternating random-dot patterns. Our experimental results demonstrate that (i) disparities from simultaneous monocular inputs dominate those from interocular delayed inputs; (ii) stereopsis is limited by temporal properties of monocular luminance mechanisms; and (iii) depth perception in dynamic random-dot stereograms results from cross-correlation-like operation on two simultaneous monocular inputs that represent the retinal images after having been subjected to a process of monocular temporal integration of luminance.     

Maternal attitudes and attachment styles in mothers of obese children

This study evaluated categories of attachment style and the maternal attitude toward educational role in a sample of 30 mothers of obese children and a control group of 80 mothers of children of normal weight. All mothers completed the 1994 Attachment Style Questionnaire and the 1958 Parental Attitude Research Instrument. 30 mothers (M age 37.4 yr., range 31 to 54 years; M yr. of education 11.6, range 5 to 18 years) of obese children (range 30 to 60% above normal weight) and a control group of 80 mothers (M age 37.1 yr., range 29 to 52 years; M yr. of schooling 11.4, range 5 to 18 years) of children with normal weight were contacted at the primary school attended by their children and joined the project voluntarily. Age and number of years of education were not significantly different between the two groups of women. There was a significant prevalence of the Insecure Attachment Style in the group of mothers with obese children (66.6%) as compared to the control group of mothers of children of normal weight (38.5%) and significantly higher scores on 6 subscales of the Parental Attitude Research Instrument of Obese compared to Nonobese children. These data indicate that obese children's mothers tend to make the family their exclusive centre of interest. They also tend to dedicate themselves to their children with possessiveness and hyperprotection. They seem to have an insistent requirement of idealisation of their own role as parent and reward expectations that confirm the efficiency of the care they provide their children. Consequently, these findings suggest that in addition to dietetic treatment, it may be important to include a psychological intervention, which involves the mother and aims to modify the relational dynamics between the mother and her obese child.     

I love you too much to keep social distance: Closeness in relationships and (dis)engagement in preventive behaviors during the COVID-19 pandemic

Although we are witnessing a new phase in the management of COVID-19, understanding what predicts adherence to preventive behaviors still remains crucial. In this study we focus on interpersonal relationships by specifically investigating whether engagement in preventive behaviors when in the presence of others may be a function of the type of relationship (in terms of closeness) one has with others. Because close others are often perceived similar to the self compared to strangers, we put forward that close relationships may inadvertently decrease COVID-19 risk perceptions which may ultimately decrease compliance with recommended behaviors when in their presence. To test this hypothesis, 747 Italian respondents were invited to answer one out of four versions of a questionnaire differing on the target (i.e., friends vs. parents vs. grandparents vs. strangers), including questions regarding COVID-19 risk perceptions and intentions to engage in preventive behaviors. Mediation analysis showed that close relationships (i.e., with friends, parents, and grandparents) compared to nonclose relationships (i.e., with strangers) predicted lower intentions to engage in preventive behaviors via lower risk perceptions. Altogether, these results shed light on the role played by closeness in indirectly shaping individuals' dis(engagement) in preventive behaviors and contribute to better understand possible unconscious biases which may undermine our safety during the COVID-19 pandemic.     

The increasing relevance of European rural young people in policy agendas: Contributions from community psychology

Our paper aims to provide a short guide on how community psychologists can contribute to the improvement of rural young people's prospects. After briefly introducing the demographic trends of these young people in continental Europe for the past decade, we list the current challenges faced by rural European young generations, as well as the opportunities emerging for them from the twin transition that can inspire the community psychology field. We then contextualize community psychologists' interventions in this domain according to an ecological-systemic standpoint and by embracing a Participatory Action Research (PAR) perspective on research and practice. We further detail the reasons for adopting a PAR approach in research and practice to address rural young people's challenges and opportunities. Finally, we highlight four potential intermediation missions to uphold community psychologists' rural youth development input, based on the adopted theoretical and methodological standpoint. We conclude that our short guide can facilitate community psychology professionals' complete understanding of rural young generations' prospects, in line with the expected increase in the need for rural young people's participation. Our proposal may also have long-term benefits for rural communities by contributing to the redesigning of intergenerational relationships and securing critical mass.