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451.
Whitney I. Mattson Naomi V. Ekas Brittany Lambert Ed Tronick Barry M. Lester Daniel S. Messinger 《Infant behavior & development》2013
In infants, eye constriction—the Duchenne marker—and mouth opening appear to index the intensity of both positive and negative facial expressions. We combined eye constriction and mouth opening that co-occurred with smiles and cry-faces (respectively, the prototypic expressions of infant joy and distress) to measure emotional expression intensity. Expression intensity and heart rate were measured throughout the face-to-face/still-face (FFSF) in a sample of infants with prenatal cocaine exposure who were at risk for developmental difficulties. Smiles declined and cry-faces increased in the still-face episode, but the distribution of eye constriction and mouth opening in smiles and cry-faces did not differ across episodes of the FFSF. As time elapsed in the still face episode potential indices of intensity increased, cry-faces were more likely to be accompanied by eye constriction and mouth opening. During cry-faces there were also moderately stable individual differences in the quantity of eye constriction and mouth opening. Infant heart rate was higher during cry-faces and lower during smiles, but did not vary with intensity of expression or by episode. In sum, infants express more intense negative affect as the still-face progresses, but do not show clear differences in expressive intensity between episodes of the FFSF. 相似文献
452.
Regional differences in IQ are estimated for 47 prefectures of Japan. IQ scores obtained from official achievement tests show a gradient from north to south. Latitudes correlate with height, IQ, and skin color at r = 0.70, 0.44, 0.47, respectively. IQ also correlates with height (0.52), skin color (0.42), income (0.51) after correction, less homicide rate (− 0.60), and less divorce (− 0.69) but not with fertility infant mortali'ty. The lower IQ in southern Japanese islands could be attributable to warmer climates with less cognitive demand for more than fifteen hundred years. 相似文献
453.
Selective attrition is a potentially serious problem that can bias the findings that are generated from longitudinal samples. Although the extent to which IQ might be involved in selective attrition has been studied, the results from these studies have been decidedly mixed. The current study adds to the literature examining the link between IQ and selective attrition by examining four waves of data from the National Longitudinal Study of Adolescent Health. Analysis of these data revealed that IQ is related to attrition, with lower IQ respondents more likely to drop out of the study when compared against higher IQ respondents. The evidence suggests that dropouts score about 4.5 IQ points lower than subjects who did not drop out. Limitations of the study are noted and directions for future research are discussed. 相似文献
454.
Amy L. Gentzler Amanda L. Wheat Cara A. Palmer Rebecca A. Burwell 《Cognition & emotion》2013,27(2):305-317
We tested the hypothesis that less effective responses during a cognitive challenge would relate to higher levels of self-reported rumination in children. The sample was 100 children (55 boys, 45 girls), aged 7 to 14 years. A portion (n=65) was at high risk for depression due to having a parent with a childhood-onset mood disorder, and 35 were a low-risk comparison group. Using an impossible puzzle task, we assessed children's responses following failure across several domains: emotions (expressed anger, sadness, and negative self-statements), performance (being off-task, the time to solve subsequent puzzles, and the number solved), and physiology (heart rate, respiratory sinus arrhythmia). Results indicated that making negative self-blaming statements during the solvable puzzles and taking more time to solve the puzzles were associated with higher levels of self-reported rumination. Our findings advance the understanding of potential correlates of children's tendency to ruminate and may have implications for children's performance on cognitive tasks. 相似文献
455.
Joshua M. Smyth Michelle H. Soefer Adam Hurewitz Arthur A. Stone 《Psychology & health》2013,28(3):487-501
Abstract Evidence indicates that psychological stress plays a role in precipitating and exacerbating asthma symptoms and suggests that relaxation techniques aimed at reducing stress and autonomic arousal leads to symptom reduction. This study explored the effect of a tape-recorded relaxation intervention on well-being (mood and stresson). asthma symptoms, and a measure of pulmonary function (PEFR). Twenty adult asthmatics were studied for 21 days in their natural environment using a multiple baseline design. Self-administered relaxation training (including both breathing exercises and muscle relaxation) led to decreased negative mood and stressor report. Reporting of asthma symptoms decreased over time, and PEFR was increased by relaxation training. Asthma medication use was unchanged. Results suggest that tape–recorded relaxation training positively impacts well-being, asthma symptoms. and PEFR in a naturalistic setting. Further study of the potential use of inexpensive tape-recorded interventions in chronic illness is warranted. 相似文献
456.
457.
Micheal Kattoura 《Philosophical Magazine Letters》2013,93(7):415-423
Multiscale dislocation dynamics plasticity (MDDP) calculations are carried out to simulate the mechanical response of copper single crystals that have undergone shock loading at high strain rates ranging from 1?×?106 to 1?×?1010?s?1. Plasticity mechanisms associated with both the activation of pre-existing dislocation sources and homogeneous nucleation of glide loops are considered. Our results show that there is a threshold strain rate of 108?s?1 at which the deformation mechanism changes from source activation to homogeneous nucleation. It is also illustrated that the pressure dependence on strain rate follows a one-fourth power law up to 108?s?1 beyond which the relationship assumes a one-half power law. The MDDP computations are in good agreement with recent experimental findings and compare well with the predictions of several dislocation-based continuum models. 相似文献
458.
The thermal stability and glass-forming ability (GFA) of Se80? x Te20Ag x (x?=?0,?3,?5,?7 and 9) chalcogenide glasses have been investigated using differential scanning calorimetry (DSC). The DSC runs have been taken at five different heating rates (10, 20, 30, 40 and 50?K/min) under non-isothermal condition. The thermal stability and GFA are monitored through determination of the temperature difference ΔT?=?T c???T g, where T c is the onset crystallization temperature, T g is the glass transition temperature, H l is the stability parameter, ΔH c is the enthalpy released during crystallization and F i is the fragility index. The activation energy of crystallization E c and crystallization rate factor K have also been determined as indicators of the thermal stability of the above-mentioned samples. It is found that Se71Te20Ag9 is the most stable among all the samples of the series. 相似文献
459.
探讨急性心肌梗死(AMI)患者直接经皮冠状动脉介入(PCI)前后窦性心律振荡(HRT)的变化及意义.选择伴室性早搏的AMI患者(观察组)和无器质性心脏病的室性早搏患者(对照组)各42例,PCI前伴室早的观察组患者,用节律Ⅱ导联记录室早的心电图,PCI后2周时观察组及对照组均记录24h动态心电图(AECG),计算其震荡初始(TO)和震荡斜率(TS),并行心脏彩色多普勒超声检查,测定左室射血分数(LVEF).结果观察组PCI后2周时和对照组LVEF分别为:(59.1±7.5)%和(61.3±8.4)%.观察组PCI前TO显著升高,TS显著降低,差异有统计学意义(P<0.05);观察组PCI后2周TO较前降低,TS较前升高,但和对照组相比差异仍有统计学意义(P<0.05);观察组PCI后2周时和对照组左室射血分数(LVEF)相比无差异.提示AMI患者HRT减弱,PCI后2周HRT改善但和观察组相比仍有统计学意义,提示AMI患者PCI后早期仍存在心脏自主神经功能下降,HRT可作为评价AMI患者预后的一个指标. 相似文献
460.
Carlos Eduardo Costa André Connor de Méo Luiz Lucas Franco Carmona Guilherme Dutra Ponce Roberto Alves Banaco Kennon A. Lattal 《Journal of the experimental analysis of behavior》2024,121(2):163-174
Behavioral momentum theory (BMT) provides a theoretical and methodological framework for understanding how differentially maintained operant responding resists disruption. A common way to test operant resistance involves contingencies with suppressive effects, such as extinction or prefeeding. Other contingencies with known suppressive effects, such as response-cost procedures arranged as point-loss or increases in response force, remain untested as disruptive events within the BMT framework. In the present set of three experiments, responding of humans was maintained by point accumulation programmed according to a multiple variable-interval (VI) VI schedule with different reinforcement rates in either of two components. Subsequently, subtracting a point following each response (Experiment 1) or increasing the force required for the response to be registered (Experiments 2 and 3 decreased response rates, but responding was less disrupted in the component associated with the higher reinforcement rate. The point-loss contingency and increased response force similarly affected response rates by suppressing responding and human persistence, replicating previous findings with humans and nonhuman animals when other types of disruptive events (e.g., extinction and prefeeding) were investigated. The present findings moreover extend the generality of the effects of reinforcement rate on persistence, and thus BMT, extending the analysis of resistance to two well-known manipulations used to reduce responding in the experimental analysis of behavior. 相似文献