Promoting response variability and stimulus generalization in martial arts training

The effects of reinforcement and extinction on response variability and stimulus generalization in the punching and kicking techniques of 2 martial arts students were evaluated across drill and sparring conditions. During both conditions, the students were asked to demonstrate different techniques in response to an instructor's punching attack. During baseline, the students received no feedback on their responses in either condition. During the intervention phase, the students received differential reinforcement in the form of instructor feedback for each different punching or kicking technique they performed during a session of the drill condition, but no reinforcement was provided for techniques in the sparring condition. Results showed that both students increased the number of different techniques they performed when reinforcement and extinction procedures were conducted during the drill condition, and that this increase in response variability generalized to the sparring condition.     

Heart Rate Variability and Sustained Attention in ADHD Children

The major goal of the current study was to investigate the association between continuous performance tests (CPTs) and the heart rate variability (HRV) of attention deficit hyperactivity disorder (ADHD) children. The HRV, specifically the 0.10-Hz component, may be considered to be a psychophysiological index of effort allocation (motivation): The less effort the subject allocates, the greater the 0.10-Hz component. Results indicated that, compared to controls, ADHD subjects had a greater 0.10-Hz component, which was associated with poor test performance over time. Thus, using a psychophysiological measure, we were able to confirm the clinical concept of ADHD from a motivational perspective.     

Guess Who Buys Cheap? The Effect of Consumers’ Goal Orientation on Product Preference

The current research examines how goal orientation affects consumer preference among products with different prices. We argue that a less expensive product may have not only lower perceived quality but also greater perceived quality variability. This greater perceived variability provides the opportunity for optimistic, promotion‐oriented consumers to overestimate the quality of the less expensive product. This effect is weaker, however, for a more expensive product that consumers perceive to have less quality variability and which thus provides less room for quality overestimation. As a result, we hypothesize that promotion‐oriented consumers, as compared to prevention‐oriented consumers, will demonstrate a stronger preference for a less expensive product. In a field study and two laboratory experiments, we obtain empirical support both for the hypothesized effect of consumers’ goal orientation on their product preference and for its underlying process. We conclude with a discussion of the theoretical and practical implications of our results.     

Repressive coping style and autonomic reactions to two experimental stressors in healthy men and women

Autonomic and affective responses to two different stress tasks were measured in 45 males and 74 females, categorized as repressive, true low-anxious, true high-anxious, and defensive high-anxious. Electrodermal activity (EDA) was used as a measure of sympathetic activity and the high frequency (HF) spectral component of heart rate variability as a measure of parasympathetic activity. Contrary to our predictions, reactivity of repressors did not differ from the reactivity of true low-anxious participants. The results draw attention to previous inconsistent findings within the literature on repressive coping style and autonomic nervous system dysregulation. It is suggested that future research could benefit from the use of more consistent operationalizations of the repressive coping construct and from comparing alternative measures of repressive coping within the same study.     

Changes in ego development in the wake of September 11

In a longitudinal study using the Washington University Sentence Completion Test (WUSCT), we examined changes in ego development in response to the events of September 11, 2001. A sample of 24 individuals responded to the WUSCT in both the summer and fall of 2001, before and after the events of September 11. A significant decrease in mean ego level was found following September 11, as well as more equivocal support for an increase in variability in responses to the WUSCT.     

Visuomotor contribution to force variability in the plantarflexor and dorsiflexor muscles

The visual correction employed during isometric contractions of large proximal muscles contributes variability to the descending command and alters fluctuations in muscle force. This study explored the contribution of visuomotor correction to isometric force fluctuations for the more distal dorsiflexor (DF) and plantarflexor (PF) muscles of the ankle. Twenty-one healthy adults performed steady isometric contractions with the DF and PF muscles both with (VIS) and without (NOVIS) visual feedback of the force. The target forces exerted ranged from 2.5% to 80% MVC. The standard deviation (SD) and coefficient of variation (CV) of force was measured from the detrended (drift removed) VIS and NOVIS steadiness trials. Removal of VIS reduced the CV of force by 19% overall. The reduction in fluctuations without VIS was significant across a large range of target forces and was more consistent for the PF than the DF muscles. Thus, visuomotor correction contributes to the variability of force during isometric contractions of the ankle dorsiflexors and plantarflexors.     

变异性心绞痛患者心率变异性与冠状动脉病变关系的研究

研究变异性心绞痛患者 ST 段抬高对心率变异性的影响。回顾性分析122例变异性心绞痛患者 ST 段抬高幅度及持续时间对心率变异性的影响;心率变异性与冠状动脉病变及病变支数、狭窄程度有相关性。结果心率变异性在 ST 段抬高≥0．4mv 患者中较 ST 段抬高＜0．4mv 患者中明显降低（P＜0．05）;其在 ST 段抬高持续时间≥3min 患者中较 ST 段抬高持续时间＜3min 患者中明显降低（P＜0．05）;其在冠状动脉狭窄≥50％患者中较冠状动脉狭窄＜50％患者中明显降低（P＜0．05）;心率变异性在多支较单支病变明显降低（P ＜0．05）,单支病变狭窄程度≥75％较50％～75％者明显降低（P＜0．05）。提示变异性心绞痛患者自主神经系统受损程度与冠状动脉缺血严重程度,缺血持续时间密切相关,心率变异性能一定程度反映变异性心绞痛患者冠状动脉病变严重程度。     

Associations between attention,affect and cardiac activity in a single yoga session for female cancer survivors: An enactive neurophenomenology-based approach

Yoga practice is reported to lead to improvements in quality of life, psychological functioning, and symptom indices in cancer survivors. Importantly, meditative states experienced within yoga practice are correlated to neurophysiological systems that moderate both focus of attention and affective valence. The current study used a mixed methods approach based in neurophenomenology to investigate associations between attention, affect, and cardiac activity during a single yoga session for female cancer survivors. Yoga practice was associated with a linear increase in associative attention and positive affective valence, while shifts in cardiac activity were related to the intensity of each yoga sequence. Changes in attention and affect were predicted by concurrently assessed cardiac activity. Awareness of breathing, physical movement, and increased relaxation were reported by participants as potential mechanisms for yoga’s salutary effects. While yoga practice shares commonalities with exercise and relaxation training, yoga may serve primarily as a promising meditative attention-affect regulation training methodology.     

Graphomotor skills in children with developmental coordination disorder (DCD): Handwriting and learning a new letter

The aim of the present study was to analyze handwriting difficulties in children with developmental coordination disorder (DCD) and investigate the hypothesis that a deficit in procedural learning could help to explain them. The experimental set-up was designed to compare the performances of children with DCD with those of a non-DCD group on tasks that rely on motor learning in different ways, namely handwriting and learning a new letter. Ten children with DCD and 10 non-DCD children, aged 8–10 years, were asked to perform handwriting tasks (letter/word/sentence; normal/fast), and a learning task (new letter) on a graphic tablet. The BHK concise assessment scale for children’s handwriting was used to evaluate their handwriting quality. Results showed that both the handwriting and learning tasks differentiated between the groups. Furthermore, when speed or length constraints were added, handwriting was more impaired in children with DCD than in non-DCD children. Greater intra-individual variability was observed in the group of children with DCD, arguing in favor of a deficit in motor pattern stabilization. The results of this study could support both the hypothesis of a deficit in procedural learning and the hypothesis of neuromotor noise in DCD.