Differential effects of stimulus characteristics during knee joint perturbation on hamstring and quadriceps reflex responses

When stretching muscles of the ankle joint, stretch velocity and amplitude were shown to selectively influence specific parts of the stretch reflex. The present study investigated whether similar effects can be observed at the knee joint. Seventeen subjects were exposed to sudden anterior tibial translations. The influence of stimulus amplitude was analyzed by applying a low (LIMP) or high impulse (HIMP). To investigate the influence of velocity, rate of force development of the perturbation was chosen either low (LRFD) or high (HRFD). Activation of biceps femoris (BF), semitendinosus (ST), vastus medialis (VM) and vastus lateralis (VL) was calculated in four consecutive timeframes (P0, P1, P2, P3). During P1, RFD (ST: p < .05; BF: p < .01; VM: p < .05; VL: p > .05) and during P2, impulse (ST: p < .05; BF: p < .01; VM: p < .01; VL: p < .01) did significantly influence reflex activation. The present study showed that stimulus characteristics influenced specific reflex components of knee joint muscles. As only hamstring muscles were stretched, whereas quadriceps was unloaded, it is concluded that different mechanisms like homonymous and heteronymous muscle afferents as well as joint and skin afferents might contribute to the reflex responses.     

Gait training facilitates push-off and improves gait symmetry in children with cerebral palsy

BackgroundHuman walking involves a rapid and powerful contraction of ankle plantar flexors during push-off in late stance.ObjectiveHere we investigated whether impaired push-off force contributes to gait problems in children with cerebral palsy (CP) and whether it may be improved by intensive gait training.MethodsSixteen children with CP (6–15 years) and fourteen typically developing (TD) children (4–15 years) were recruited. Foot pressure was measured by insoles and gait kinematics were recorded by 3-dimensional video analysis during treadmill and overground walking. The peak derivative of ground reaction force at push off (dPF) was calculated from the foot pressure measurements. Maximal voluntary plantar flexion (MVC) was measured while seated. Measurements were performed before and after a control period and after 4 weeks of 30 minutes daily inclined treadmill training.ResultsdPF and MVC were significantly lower in children with CP on the most affected (MA) as compared to TD children (p < .001). dPF was lower on the MA leg as compared to the less affected (LA) leg in children with CP (p < .05). Following gait training, increases in dPF (p < .001) and MVC (p < .01) were observed for the MA leg. Following gait training children with CP showed similar timing of dPF and similar stance phase duration on both legs indicating improved symmetry of gait. These effects were also shown during overground walking.ConclusionImpaired ability to voluntarily activate ankle plantar flexors and produce a rapid and powerful push-off during late stance are of importance for impaired gait function in children with CP. Intensive treadmill training may facilitate the drive to ankle plantar flexors and reduce gait asymmetry during both treadmill and overground walking.     

The buffering power of overt socially supportive and unsupportive behaviors from the significant other on posttraumatic stress disorder individuals’ emotional state

Background and objectives: Social support is one of the three strongest predictors of posttraumatic stress disorder (PTSD). In the present study, we aimed to assess the buffering power of overt socially supportive and unsupportive behaviors from the significant other, in a group with PTSD and a comparison group. Design and methods: A total of 46 individuals with PTSD and 42 individuals with obsessive-compulsive disorder (OCD) or panic disorder (PD) completed diagnostic interviews and an anxiety-oriented social interaction with a significant other. Heart rate of participants was continuously measured during this interaction and overt social behaviors from the significant other were recorded on videotape and coded using a validated system. Results: Changes in heart rate in PTSD participants correlated negatively with changes in overt socially supportive behaviors from their significant other (r from ?.36 to ?.50, p?<?.05), while changes in overt unsupportive social behaviors from their significant other did not yield any significant correlation (r from ?.01 to .05, p?>?.05). No such statistically significant association emerged in the group with OCD or PD (r from .01 to ?.27, p?>?.05). Conclusions: This study sustain the buffering power of overt supportive behaviors from the significant other on heart rate changes in PTSD.     

Muscle coordination and force variability during static and dynamic tracking tasks

This study examined muscular activity patterns of extensor and flexor muscles and variability of forces during static and dynamic tracking tasks using compensatory and pursuit display. Fourteen volunteers performed isometric actions in two conditions: (i) a static tracking task consisting of flexion/pronation, ulnar deviation, extension/supination and radial deviation of the wrist at 20% maximum voluntary contraction (MVC), and (ii) a dynamic tracking task aiming at following a moving target at 20% MVC in the four directions of contraction. Surface electromyography (SEMG) from extensor carpi ulnaris, extensor carpi radialis, flexor carpi ulnaris and flexor digitorum superficialis muscles and exerted forces in the transverse and sagittal plane were recorded. Normalized root mean square and mutual information (index of functional connectivity within muscles) of SEMGs and the standard deviation and sample entropy of force signals were extracted. Larger SEMG amplitudes were found for the dynamic task (p < .05), while normalized mutual information between muscle pairs was larger for the static task (p < .05). Larger size of variability (standard deviation of force) concomitant with smaller sample entropy was observed for the dynamic task compared with the static task (p < .01 for both). These findings underline a rescaling of the muscles’ respective contribution influencing force variability relying on feedback and feed-forward control strategies in relation to display modes during static and dynamic tracking tasks.     

Coordination of Eye and Leg Movements During Visually Guided Stepping

In the present study, 2 related hypotheses were tested: first, that vision is used in a feedforward control mode during precision stepping onto visual targets and, second, that the oculomotor and locomotor control centers interact to produce coordinated eye and leg movements during that task. Participants' (N = 4) eye movements and step cycle transition events were monitored while they performed a task requiring precise foot placement at every step onto irregularly placed stepping stones under conditions in which the availability of visual information was either restricted or intermittently removed altogether. Accurate saccades, followed by accurate steps, to the next footfall target were almost always made even when the information had been invisible for as long as 500 ms. Despite delays in footlift caused by the temporary removal (and subsequent reinstatement) of visual information, the mean interval between the start of the eye movement and the start of the swing toward a target did not vary significantly (p > .05). In contrast, the mean interval between saccade onset away from a target and a foot landing on that target (stance onset) did vary significantly (p < .05) under the different experimental conditions. Those results support the stated hypotheses.     

Relationships Between Scores on the General Purpose Abbreviated Battery of Stanford-Binet IV,Peabody Picture Vocabulary Test-Revised,Columbia Mental Maturity Scale,and Goodenough-Harris Drawing Test

This study investigated the correlations among the “General Purpose Abbreviated Battery” of the Stanford-Binet IV: Fourth Edition, the Peabody Picture Vocabulary Test-Revised, the Columbia Mental Maturity Scale, and the Goodenough-Harris Drawing Test. A third-grade class of 23 children (11 boys, 12 girls) took all four of the tests, and the intercorrelations of the total scores of the four tests were calculated. The Binet IV and Peabody correlation was statistically significant (p < .01) as was the correlation between Binet IV and Columbia (p < .05). The correlation between Binet IV and Goodenough-Harris was not statistically significant (p > .05).

     

Psychophysiological correlates of organizational change and threat of unemployment among police inspectors

The study examined psychosocial work-conditions and physiological reactions among thirty-six police inspectors (median age 45 years, 81% males) who participated in a reorganization. At this time, subjects were threatened by unemployment and had to reapply for their positions in a new police district. Data were collected during the reorganization and at three years follow-up, by means of questionnaires (Stress Profile) and blood samples. The blood samples were used to determine serum levels of gammaglutamyltransferase (GGT), glucose, lipids, prolactin, testosterone and cortisol. The results show a positive association betweenworry about employment and symptoms ofburnout during the reorganization. Mean scores for the Stress Profile sub-scalesworry about employment (p<.01) andwork-load (p<.05) decreased between measurements but an impairment inrelationships with management was noticed (p<.05). No significant changes were observed in terms of self-rated health complaints. Significant decreases in total cholesterol (p<.0001), LDL-cholesterol (p<.0001), LDL/HDL-ratio (p<.01), prolactin (p<.0001), as well as increases in testosterone (p<.01) and cortisol (p<.001) were observed for the whole sample. Glucose decreased with marginal significance (<.07). Controlling for age and gender, multivariate regression analyses showed that subjects who reported deteriorations insatisfaction with work manifested the most modest decreases in prolactin (p<.05). Also, the decrease in glucose was larger for subjects who experienced impairments in,satisfaction with work (p<.05), information (p<.05), task-oriented leadership, (p<.05), andrespect and dignity (p<.05). Subjects who perceived deteriorations in theethical and moral standards of the organization increased their cortisol level to a lower degree than their counterparts (p<.05). Favorable changes in employment status and psychosocial work environment seem to be related to improved physiological functioning.     

Alibi believability: Corroborator certainty,cooperativeness and relationship with the defendant

Alibi believability can be affected by characteristics of the alibi corroborator, including the relationship between the defendant and corroborator, which has been studied extensively by researchers. The corroborator's certainty that they were together at the time of the crime may also influence alibi believability, but only a few studies have examined this. Another factor that may affect believability is the corroborator's cooperativeness with the police, which is yet to be studied in the alibi context. Online U.S. participants recruited from CloudResearch (N = 280) acted as mock jurors and evaluated a mock arson case where the defendant used an alibi defence. The alibi corroborator's relationship to the defendant (brother/neighbour), the certainty that they were together at the time (65%/100%) and cooperativeness with police (cooperative/uncooperative) were manipulated between participants. The participants were evenly split when it came to verdict (p > .05) but were more likely to vote guilty when the corroborator was a brother rather than a neighbour (p < .01) and when the brother was uncooperative versus cooperative (p < .05). As expected, alibis were more believable when they were corroborated by a neighbour rather than a brother and when the corroborator was 100% certain that they were together versus 65% certain (ps < .01). Alibis were also more believable when the corroborator cooperated than when he was uncooperative (p < .01). Cooperative (vs. uncooperative) corroborators led to more positive defendant and corroborator views on all six character trait measures (ps < .01). Implications and future directions are discussed.     

Effects of Electromyostimulation on Knee Extensors and Flexors Strength and Steadiness in Older Adults

It is known that electromyostimulation (EMS) alone or superimposed over voluntary contraction (EV) can effectively improve muscle strength. However, the effect of this type of training on the ability to control force production at submaximal levels is unknown. The authors examined the effects of EV training on steadiness in force production of knee extensors and flexors in older adults. Forty participants, including 20 men and 20 women, 60–77 years of age, were randomly allocated into a control group (CG) and an electromyostimulation superimposed over voluntary contraction (EVG) group. The EVG performed 30 bilateral isometric knee extension and flexion contractions per session, 3 training sessions per week, for 6 weeks. The variations in force production, expressed in absolute (standard deviation [SD]) and relative (coefficient of variation [CV]) terms, were assessed in isometric contractions at 5%, 15% and 25% maximal voluntary contraction (MVC) levels. Results indicated that MVC increased in knee extension and flexion in EVG (p < .05) after the training; steadiness CV also improved at 15% MVC in knee flexion (p < .05) but no significant changes were found in knee extension and steadiness SD. The training-induced changes in MVC were not correlated to steadiness CV that might indicate different mechanisms underlying these adaptations.     

Learning from Spiritual Models and Meditation: A Randomized Evaluation of a College Course

Effects of two meditation and mindfulness-based spiritual interventions were examined in college undergraduates (N=44). Compared to a control group, both interventions decreased negative religious coping (d=−0.80, p<.01) and images of God as mainly controlling (d=−.73, p<.01). One intervention provided more training in tools for learning from community and tradition-based spiritual exemplars. It produced gains in famous or traditional spiritual exemplars’ perceived influence (d=+.81, p<.05) and availability (d=+.66, p<.10), in self-efficacy for learning from spiritual exemplars (d=+.92, p<.05), and in nonmaterialistic aspirations (d=+0.65, p<.05).     

Gender Differences in Body Size Dissatisfaction Among Individuals With Low,Medium, or High Levels of Body Focus

The authors designed the present study to test whether women reported higher levels of body dissatisfaction than did men even when the 2 genders were matched on a measure of degree of body focus. Sixty undergraduates (30 men, 30 women) were screened on attention-to-body-shape scores and divided into high, medium, and low body-shape-focus groups. The participants also completed questionnaires that provided information on age, education, vocabulary ability, levels of depression, and body-image assessment. The groups did not differ (ps > .05) on age, education, vocabulary ability, or levels of depression. However, women in all 3 body-shape-focus categories indicated a larger discrepancy between their real vs. ideal body images (p < .01) than did the men. In the high-body-focus group, there was an 11:1 ratio between women's and men's reported real-ideal body-shape discrepancies. Women showed greater body dissatisfaction than did men, even when the genders were matched on a measure of body focus.     

Maternal and paternal parenting styles associated with relational aggression in children and adolescents: A conceptual analysis and meta-analytic review

How does parenting affect relational aggression in children? The goal of the present series of meta-analyses based on 48 studies (28,097 children) was to analyze and integrate the findings on the associations between various types of parenting behaviors and relational aggression, and to identify potential substantive and methodological factors that may moderate these associations. To distinguish between different parenting strategies, experts sorted the parenting measures used in the studies into 10 groups. Results of a multiple correspondence analysis revealed four separate clusters: Positive parenting, psychologically controlling parenting, negative/harsh parenting, and uninvolved parenting. The meta-analyses demonstrated that more positive parenting was associated with less relational aggression (combined effect sizes r = −.06, p < .05, for mothers, r = −.08, p < .01, for fathers). More harsh parenting (combined effect sizes r = .11, p < .01, for mothers, r = .12, p < .01, for fathers) and more uninvolved parenting (combined effect sizes r = .07, p < .01, for mothers, absent for fathers) were associated with increased relational aggression. Paternal psychologically controlling parenting was positively related to relational aggression (r = .05, p < .01), whereas maternal psychologically controlling parenting was not (combined effect sizes r = .04, p = .09). The effect of several moderators is discussed. The findings of this study suggest that dimensions of positive and negative parenting behaviors of mothers and fathers are associated with children’s relational aggression and that these associations are – in case of fathers – contingent upon a number of sampling and procedural characteristics.     

Associations between psychological characteristics and indicators of metabolic syndrome among Chinese adults

Current knowledge about the relationship between psychological characteristics and metabolic syndrome (MetS) components is limited in Asian populations. The purpose of this study is to investigate linkages between physiological markers of MetS and life satisfaction, hostility, and depression in Chinese adults. Secondary analyses were conducted using cross-sectional data from parents of randomly selected middle school students participating in a pilot study in Qingdao, China. Among 440 parents who consented to participate (237 women, 203 men), 368 provided valid responses in all three categories of psychological characteristics, and only those subjects were included in these analyses. General linear models and logistic regressions were run separately by gender, controlling for covariates. Among women, life satisfaction was inversely associated with triglyceride levels (p = .04), LDL-C (p < .01), risk of hypertriglyceridemia (OR[.53], p < .01), HDL-C (OR[.78], p = .03), and MetS (OR[.52], p = .03). No associations were found between life satisfaction and any psychological characteristics among men. Among women, hostility was positively associated with triglyceride level (p = .04) and risk of hypertriglyceridemia (OR[2.12], p < .05). Among men, hostility was positively associated with waist circumference (p = .04), waist-hip ratio (p < .05), and fasting plasma insulin (p < .01). Depression was not associated with any physiological measurement in either gender. These findings indicate that relationships exist between certain psychological characteristics and physiological indicators of MetS among Chinese adults, although there may be important differences between genders.     

Experimental comparison of dyspnea and pain

Dyspnea and pain are similarly unpleasant, alarming physical sensations, but studies examining both sensations in combination are lacking. In the present study, dyspnea was induced in 7 healthy volunteers by breathing through inspiratory resistive loads and the effects were compared with those of a heat pain stimulus. End-tidal partial pressures of carbon dioxide (PET_CO2), inspiratory time (Ti), breathing frequency (f), experienced unpleasantness, and intensity were measured. No difference was observed between dyspnea and pain in experienced intensity and unpleasantness (p >.05). During dyspneic stimulation, slightly higherTi was found than for pain (p<.08). PET_CO2 showed slight increases during the dyspneic versus the baseline and painful conditions (ΔPET_CO2=1.5 and 1.3 mmHg, respectively;p<.01 andp<.05). This study shows that the effects of dyspnea and heat pain can be compared within one experiment; both stimuli can be presented with similar intensity and unpleasantness, which is a prerequisite for comparing responses to them. The changes in PET_CO2 between our conditions were minimal, allowing an application of the present design to future fMRI studies.     

Degree of Disturbance in Figure Drawings as Related to Mode of Approach to Problem Solving

Spontaneous and induced hierarchical organization was investigated with 72 first, third, and fifth graders (12 females and 12 males at each grade level). Stimuli consisted of an initial set of 20 unrelated pictures and a second set of 20 pictures which could be classified according to four super ordinate categories. Ss were randomly assigned to either the spontaneous or induced condition for the second set. Both recall scores and clustering indexes indicated that induced organization facilitates recall(p < .01 and p < .05, respectively). The effect of the induced presentation condition was most pronounced for third and fifth graders (p < .05). The clustering analysis indicated sex differences in the induced presentation condition (p < .05); with increasing age, girls exhibited a greater improvement than boys in induced organizational ability.     

The relationship between allometry and preferred transition speed in human locomotion

The purpose of this study was to explore the relationships between preferred transition speed (PTS) and anthropometric characteristics, body composition and different human body proportions in males. In a sample of 59 male students, we collected anthropometric and body composition data and determined individual PTS using increment protocol. The relationships between PTS and other variables were determined using Pearson correlation, stepwise linear and hierarchical regression. Body ratios were formed as quotient of two variables whereby at least one significantly correlated to PTS. Circular and transversal (except bitrochanteric diameter) body dimensions did not correlate with PTS. Moderate correlations were found between longitudinal leg dimensions (foot, leg and thigh length) and PTS, while the highest correlation was found for lower leg length (r = .488, p < .01). Two parameters related to body composition showed weak correlation with PTS: body fat mass (r = −.250, p < .05) and amount of lean leg mass scaled to body weight (r = .309, p < .05). Segmental body proportions correlated more significantly with PTS, where thigh/lower leg length ratio showed the highest correlation (r = .521, p < .01). Prediction model with individual variables (lower leg and foot length) have explained just 31% of PTS variability, while model with body proportions showed almost 20% better prediction (R² = .504). These results suggests that longitudinal leg dimensions have moderate influence on PTS and that segmental body proportions significantly more explain PTS than single anthropometric variables.     

Some attitudinal and cognitive consequences of thought

A “reinterpretation of inconsistent cognitions” explanation of the previous finding that thought about an object tends to polarize attitudes toward that object was tested. Under the assumption that ambiguity facilitates reinterpretation, ambiguity of inconsistent information and opportunity for thought were manipulated. Consistent with expectations, (a) thought resulted in attitude polarization and this effect was increased with ambiguity (p < .01) and (b) evaluation (interpretation) of the inconsistent information varied as a function of thought (p < .05) and ambiguity (p < .01).     

Characterization of the Stanford Integrated Psychosocial Assessment for Transplant (SIPAT) in Lung Transplant Candidates

The SIPAT is a standardized measure for pre-transplant psychosocial evaluation. Previous SIPAT studies utilized a relatively small lung transplant sample and only included listed patients. This study characterized the SIPAT in 147 lung transplant candidates to better elucidate its utility. The average score corresponded to a minimally acceptable rating and nearly half of the patients had relative or absolute contraindications. Interstitial Lung Disease (ILD) patients scored more favorably than non-ILD patients (U?=?7.69, p?<?.05). The Total (β?=?? .05, SE?=?.018, p?<?.01), Social Support Subscale (β?=?? .133, SE?=?.058, p?<?.05), and Psychosocial Stability and Psychopathology Subscale (β?=?? .103, SE?=?.040, p?<?.05) significantly predicted listing status. The SIPAT has a unique profile in lung transplant candidates and demonstrated utility for guiding transplant decisions. Future research should examine which lung transplant outcomes are significantly associated with SIPAT scores.

     

The Effects of Warnings and Speeding on Scale Scores and Convergent Validity of Conscientiousness

We examined the effects of warnings and speeding on scale scores and convergent validity of a measure of Conscientiousness in a faking context (N = 329). A completely crossed 2 × 2 experimental design was used in which instructions (no warning or a warning) and speeding (with or without a time limit) were manipulated. No statistically significant effects on scale scores or convergent validity were evidenced for speeding. Warning participants did decrease Conscientiousness scores by almost 1 standard deviation (d = .91). Warnings also moderated the relationship between self- and observer-ratings of Conscientiousness such that the relationship between self- and observer-ratings was statistically significant and positive in the warned conditions (r _partial = .29, p < .01, n = 136), but this same relationship was statistically nonsignificant (r _partial = ?.14, p > .05, n = 148) in the unwarned conditions.     

Dyadic Anxiety in Youth Sport: The Relationship of Achievement Goals With Anxiety in Young Athletes and Their Parents

The role of achievement motivation on precompetitive anxiety was examined in 73 dyads comprising youth athletes and a parent of each athlete. Participants completed questionnaires assessing achievement goals and anxiety. Actor–partner interdependence models were estimated using Mplus 7.11. Parents’ adoption of performance-approach and performance-avoidance goals predicted athletes’ worry (β_{performance-approach} =.30, p <.01; β_{performance-avoidance} =.25, p <.05). Athletes’ adoption of any goal predicted parents’ concentration disruption (β_{mastery-approach} =.41; β_{mastery-avoidance} =.30, p <.01; β_{performance-approach} =.27; β_{performance-avoidance} =.22, p <.05). Thus, parental definitions of competence held for the child was related to their young athlete's emotional state and vice versa.