The effects of metronomic pendular adjustment versus tap-tempo input on the stability and accuracy of tempo perception

This study explores tempo stability and accuracy while comparing two subject-response modes: the traditional metronomic pendular adjustment task versus tap-tempo input. Experiment 1 questioned if a single correct tempo measurement consistently emerges from repeated listenings, and if subject-response mode affects tempo stability and accuracy. Experiment 2 assessed incremental improvement between two repeated sessions, and questioned the incidence of self-pacing or congruent effects of potential delays on tempo responses. While single-session studies have shown that listeners find some tempos more enjoyable, can notice discrete differences in pace, and can remember rhythmic speed over prolonged periods of time, the current study employs a multiple-session format focusing on two diametrically opposed subject-response modes. The findings show that tempo responses by listeners without formal music training were consistent across listening sessions, and that responses from tap-tempo input were significantly more stable and accurate than responses from metronomic pendular adjustment tasks.     

Some determinants of changes in preference over time

Results of longitudinal studies suggest that the stability of preferences varies across individuals, although it is unclear what variables account for these differences. We extended this work by conducting periodic assessments of preference for leisure activities over 3 to 6 months with 10 adults with developmental disabilities. Although previous research has collectively shown that preferences identified via repeated assessment are highly variable, our results showed that preferences were relatively stable for the majority (80%) of participants. In an attempt to identify some environmental determinants of shifts in preference, we provided extended daily access to high-preference items (preference-weakening manipulation) and paired access to low-preference items with social and edible putative reinforcers during brief sessions (preference-strengthening manipulation). Preference assessments continued over the course of these manipulations with 2 participants. Results showed that changes in preference across time could be produced systematically and suggest that naturally occurring changes in establishing operations or conditioning histories contribute to temporal shifts in preference. Implications for preference assessments, reinforcer usage, and planned attempts to change preferences are discussed.     

Stability of Family Interaction from Ages 6 to 18

Research has demonstrated the stability of juvenile offending during childhood and adolescence but generally has not focused on the continuity of family interactions associated with juvenile offending. The present report focused on the stability of several family interaction events and attributes (i.e., physical punishment, communication, supervision, positive parenting, and parent–child relationship) for a large sample of male adolescents and their primary caretakers, drawn from a multiyear longitudinal study that represented middle childhood through late adolescence (ages 6–18). We also assessed the impact of ethnicity, family composition, teenage motherhood, and youth delinquency on these interactions. Test–retest correlations and growth-curve analyses were used to assess relative and absolute stability of the interactions, respectively. As predicted, relative stability of family interaction was high. There was an absolute change in scores of physical punishment (decreased) compared to poor supervision and low positive parenting (both increased), whereas poor communication and bad relationship with the caretaker did not measurably change with age. Single-parent families and families with teenage mothers experienced significantly worse interactions over time than did families consisting of two biological parents present in the household. These findings are discussed in relation to the development of juvenile offending.     

Stability of Q-sort attachment security from age two to five

The current report demonstrates reliability and stability of Q-sort attachment security in a sample of 46 mothers and their children seen by two observers at age two and again at age four to six years. Security scores were correlated between ages (r=.44), and a high proportion of item-by-item correlations between ages were also significant.     

The stability of resting metabolic rate and diet-induced thermogenesis in children

The stability of resting metabolic rate and diet-induced thermogenesis was assessed in a group of 8- to 12-year-old children over two sessions. Children were first oriented to the laboratory and participated in a practice session to adapt them to the laboratory procedures. The two metabolic sessions began with the measurement of resting metabolic rate. The children were then provided a caloric challenge, with metabolic measures taken at 30-min intervals for 150 min. Results showed stable resting and integrated diet-induced thermogenic responses across sessions. Differences in the pattern of response from 30 to 60 min were observed, with the response peaking earlier in the first session.This experiment was supported in part by Grant HD19532 NICHD awarded to the first author.     

Real-time kinematic biofeedback improves scapulothoracic control and performance during scapular-focused exercises: A single-blind randomized controlled laboratory study

Emerging evidence suggests that scapular-focused therapeutic exercises hold promise for shoulder dynamic stability retraining. While recent findings show that therapeutic exercises can alter scapular neuromuscular function measured with muscle electromyography, no study has yet addressed the effects of kinematic biofeedback for improving scapulothoracic control and performance. The aim of this study was to assess the effectiveness of kinematic biofeedback on motor relearning transfer during shoulder flexion and a daily activity, on the quality of scapular-focused exercise performance, and on execution time. Thirty healthy young adults were randomly distributed into two groups. Skin mounted electromagnetic sensors were used to collect kinematic data of the thorax, scapula and humerus while subjects performed a shoulder flexion and a daily activity, prior to and after scapular-focused exercises. For both groups, the exercise execution error and the execution time determined the scapulothoracic control and performance. Significant statistical differences were found in the exercise execution error results within the experimental group (z = 5.313; p = 0.037) and between groups (u = 37.00; p = 0.001; u = 64.00; p = 0.024). This study’s results demonstrate that real-time kinematic biofeedback improves scapulothoracic control and performance during scapular-focused exercise execution.     

Dynamic stability during running gait termination: Predictors for successful control of forward momentum in children and adults

Reported differences between children and adults with respect to COM horizontal and vertical position to maintain dynamic stability during running deceleration suggest that this relationship may not be as important in children. This study challenged the current dynamic stability paradigm by determining the features of whole body posture that predicted forward velocity and momentum of running gait termination in adults and children. Sixteen adults and 15 children ran as fast as possible and stopped at pre-determined location. Separate regression analyses determined whether COM posterior and vertical positions and functional limb length (distance between COM and stance foot) predicted velocity and momentum for adults and children. COM posterior position was the strongest predictor of forward velocity and momentum in both groups supporting the previously established relationship during slower tasks. COM vertical position also predicted momentum in children, not adults. Higher COM position in children was related to greater momentum; consistent with previously reported differences between children and adults in COM position across running deceleration. COM vertical position was related to momentum but not velocity in children suggesting that strategies used to terminate running may be driven by demands imposed not just by velocity, but also the mass being decelerated.     

定量运动负荷和个性特征对动觉准确性和动作稳定性的影响

目的在于了解个性特征和定量运动负荷与同射箭运动员技术水平密切相关的肘关节动觉方位准确性和手动作稳定性的关系。研究结果表明：个性特征对肘关节动觉方位准确性和手动作稳定性的影响不显著;定量运动负荷可以使肘关节动觉方位准确性明显提高,而手动作稳定性变化不显著。本研究初步证明了韩国射箭训练中利用跑步等手段使运动员处于较高心率之下进行射准练习的方法是实用有效的。