Condom Use Among U.S. Students: The Importance of Confidence in Normative and Attitudinal Perceptions

Abstract

The author performed a study among U.S. undergraduates to test an earlier conclusion (D. Trafimow, 1994) that confidence in the correctness of one's perceptions of normative pressure to use a condom influences the correspondence between those perceptions and the intentions actually to perform the behavior. Consistent with previous findings (Trafimow), the participants' perceptions of normative pressure strongly predicted their intentions to use condoms only under conditions of extreme normative confidence. Otherwise, their attitudes were better predictors of their intentions to use condoms. In addition, 2 other variables (attitudinal confidence and perceived behavioral control) were found to be unimportant predictors of intentions. Results of a 2nd study suggest that behaviors performed by sexual partners and knowing the sexual partners affected the participants' normative confidence.     

Measures of dynamic stability: Detecting differences between walking overground and on a compliant surface

Numerous measures of dynamic stability have been proposed to gauge fall risk in the elderly, including stride interval variability and variability of the center of mass. However, these measures have been deemed inadequate because they do not take into account temporal information. Therefore, research on the measurement of dynamic stability has turned to other analysis methods such as stride interval dynamics and the maximum Lyapunov exponent. Stride interval dynamics reflect the statistical persistence of an individual’s stride interval time series and the Lyapunov exponent quantifies local dynamic stability – the sensitivity of the system to infinitesimal perturbations. In this study, we compare the ability of these measurement tools to detect changes between overground and compliant-surface walking, a condition known to affect stability, to determine their aptness as measures of dynamic stability. Fourteen able-bodied participants completed three 15 min walks, two overground and one on a compliant surface. Our results show that the Lyapunov exponent may be more sensitive to gait changes than stride interval dynamics and gait variability measures.     

On approximate confidence intervals for measures of concordance

The use ofU-statistics based on rank correlation coefficients in estimating the strength of concordance among a group of rankers is examined for cases where the null hypothesis of random rankings is not tenable. The studentizedU-statistics is asymptotically distribution-free, and the Student-t approximation is used for small and moderate sized samples. An approximate confidence interval is constructed for the strength of concordance. Monte Carlo results indicate that the Student-t approximation can be improved by estimating the degrees of freedom.Research partially supported on ONR Contract N00014-82-K-0207.     

时距认知与疼痛的双向关系及其思考

时距认知与疼痛的关系成为研究者重点关注的主题之一。为了帮助研究者更完整地理解这两种关系及其潜在机制以及更有效地干预疼痛和时距认知, 首先从双向关系的视角指出, 一方面, 疼痛导致时距认知出现延长、缩短或无影响三类结果; 另一方面, 时距认知会提高、降低或无影响疼痛的强度、忍耐力和敏感性。接着, 进一步在注意闸门理论、闸门控制理论以及神经矩阵理论等框架内解释上述结果。最后, 未来研究应重点关注几个科学问题:其一, 注意和唤醒在疼痛影响时距认知偏离方向的中介作用机制以及边界条件; 其二, 注意和唤醒在时间提示和持续时间对疼痛忍耐力或疼痛敏感性的中介作用机制以及边界条件; 其三, 疼痛干预和时间干预的操纵机制。     

预期如何影响人们对不愉快事件的体验?

本研究以味觉和痛觉两种感觉通道的体验为对象,探讨预期效价和预期信心如何影响知觉体验的结果及其作用机制。通过基于味觉和痛觉的两个实验,发现预期会影响即时知觉体验,并且预期信心在其中起到调节作用——对预期充满信心时,即时体验和对结果的预期保持一致,预期越积极即时体验越好,预期越消极即时体验越差;而对预期缺乏信心时,即时体验和预期之间呈现背离趋势,预期越积极即时体验越差,预期越消极即时体验则越好。研究结果阐明了预期影响即时体验的机制,对我们理解身心关系也具有重要的理论意义。     

Preparing fingers within and between hands: Examining the maximal preparation benefit in older age

Previous research has demonstrated an age-related deficit in the preparation of finger responses. A key question is whether the age-related deficit reflects differences in speed of preparation or differences in the maximal preparation benefit that can be attained given sufficiently long preparation intervals. The present study examined this issue by asking a group of younger and older adults to perform the finger-cueing task with four, relatively long, preparation intervals that varied randomly across trials. Reaction time results demonstrated that older adults were deficient in preparing two fingers on two hands at the two shortest preparation intervals, but not at the two longest ones. This outcome suggests that, with randomised preparation intervals, older adults require more time than younger adults to achieve the maximal level of between-hands preparation.     

Attention to Visual Feedback in Motor Learning

Visual guidance and movement to a stop were used to train subjects to make a simple movement without experiencing error in practice. Movement to a stop led to test performance as accurate as that after training with KR, but visual guidance did not. If a continuous visual cue as well as a stop were present during practice, subjects also performed less accurately, although they did not need to attend to the visual cue. All types of training were better than no training at all. Results are discussed in terms of the role of visual feedback in the development and assessment of programs for movement.     

Utilisation des intervalles de confiance au lieu des tests de signification : aspects épistémologiques et pratiques

The use of confidence intervals instead of significance tests is strongly recommended by the fifth edition of the manual of the American Psychological Association (2001). This possibility as well as other improvements in statistical practice are discussed in the framework of the major theoretical options subtending statistical inference and the way they have been applied in psychology for about 50 years. First, the suggestion of a complete ban on statistical testing is examined and rejected. Next, a procedure consisting in measuring the fit of two competing models based on the likelihood ratio is judged interesting and commendable. Finally, the superiority of an approach based on confidence intervals instead of significance tests is assessed and illustrated by its application to an experimental study aiming to demonstrate the absence instead of the presence of an effect of the independent variable.