The influence of preparedness on rapid stepping in young and older adults

Objective: To investigate the influence of age and preparation level on postural muscle activation and step completion time during a rapid step task. Design: Postural muscle onset times (EMG) and ground reaction forces were recorded from healthy young (n = 20, age 21 +/- 3 years) and older (n = 25, age 71 +/- 5 years) female adults during a choice reaction-time stepping paradigm. Main outcome measures: Onset times of six trunk and hip muscles, reaction time and components of the step (weight shift time, step time and task time) were recorded. Results: Muscle activation was delayed and movement time was lengthened in both young and older adults when poorly prepared for a stepping task. While reduced preparation did not influence older adults to a greater extent than young adults, the slowest step response and completion time was evident in older adults when poorly prepared to move. Conclusions: A late postural response when poorly prepared to move may be a contributing factor to an increased risk of overbalancing in older adults. Future assessment of and intervention to improve postural stability in older adults should be expanded to incorporate tasks performed at various levels of preparation.

Muscle coordination during rapid force production by young and older adults

Background. Older adults typically exhibit dramatic reductions in the rate of force development and deficits in the execution of rapid coordinated movements. The purpose of the current study was to investigate the association between the reduced rate of force development exhibited by older adults and the ability to coordinate groups of muscles. Methods. The performance of a visually guided aiming task that required the generation of isometric torque about the elbow joint was compared in 10 young adults (age range, 19 to 29 years) and 10 older adults (age range, 65 to 80 years). Participants were required to exert isometric torque in flexion, extension, pronation, or supination, or in combinations of these directions, to reach a target in minimum time. Surface electromyograms were obtained from the biceps brachii, triceps brachii, brachioradialis, and flexor carpi radialis. Results. Older participants exhibited slower target acquisition times compared with young participants (p < .05), with the extent of the differences between the groups varying markedly between target locations. Conclusions. The impairment in performance, although partially attributable to a general decline in the ability to produce force rapidly, was also affected by the requirements for muscular coordination. At the neuromuscular level, differences between the young and the elderly were expressed most prominently in the bifunctional muscle biceps brachii and in certain temporal aspects of muscular coordination.

Predictors of young dating adults' inclination to engage in extradyadic sexual activities: A multi-perspective study

Using a multi-perspective vignette design, we explored predictors of young peoples' (N = 119) propensity to engage in unfaithful activities while dating. Demographic measures, a datding investment model, and measures of functional and dysfunctional impulsivity were used to predict inclination to engage in each of two extradyadic activities (kissing and sexual activity). The results of moderated multiple regression analyses revealed that a respondent's number of sexual partners, level of dysfunctional impulsivity, satisfaction with current relationship, and quality of relationship alternatives significantly predicted inclination to engage in both of the extradyadic activities. Consistent with previous findings, gender only showed significant predictive value in relation to extradyadic sex inclination. Moreover, the association between sex, love, and marriage interacted with gender in the prediction of both extradyadic activities and interacted with commitment in the prediction of extradyadic sex inclination. Suggestions for future research in this area are offered in light of these new findings.

Why children and adults sometimes (but not always) compute implicatures

Noveck (2001) argued that children even as old as 11 do not reliably endorse a scalar interpretation of weak scalar terms (some, might, or) (cf. Braine & Rumain, 1981; Smith, 1980). More recent studies suggest, however, that children's apparent failures may depend on the experimental demands (Papafragou & Musolino, 2003). Although previous studies involved children of different ages as well as different tasks, and are thus not directly comparable, nevertheless a common finding is that children do not seem to derive scalar implicatures to the same extent as adults do. The present article describes a series of experiments that were conducted with Italian speaking subjects (children and adults), focusing mainly on the scalar term some. Our goal was to carefully examine the specific conditions that allow the computation of implicatures by children. In so doing, we demonstrate that children as young as 7 (the youngest age of the children who participated in the Noveck study) are able to compute implicatures in experimental conditions that properly satisfy certain contextual prerequisites for deriving such implicatures. We also present further results that have general consequences for the research methodology employed in this area of study. Our research indicates that certain tasks mask children's understanding of scalar terms, not only including the task used by Noveck, but also tasks that employ certain explicit instructions, such as the training task used by Papafragou & Musolino (2003). Our findings indicate further that, although explicit training apparently improves children's ability to draw implicatures, children nevertheless fail to achieve adult levels of performance for most scalar terms even in such tasks, and that the effects of instruction do not last beyond the training session itself for most children. Another relevant finding of the present study is that some of the manipulations of the experimental context have an effect on all subjects, whereas others produce effects on just a subset of children. Individual differences of this kind may have been concealed in previous research because performance by individual subjects was not reported. Our general conclusions are that even young children (7-year olds) have the prerequisites for deriving scalar implicatures, although these abilities are revealed only when the conversational background is natural.

Testing the protracted lexical restructuring hypothesis: The effects of position and acoustic-phonetic clarity on sensitivity to mispronunciations in children and adults

Although developmental increases in the size of the position effect within a mispronunciation detection task have been interpreted as consistent with a view of the lexical restructuring process as protracted, the position effect itself might not be reliable. The current research examined the effects of position and clarity of acoustic-phonetic information on sensitivity to mispronounced onsets in 5- and 6-year-olds and adults. Both children and adults showed a position effect only when mispronunciations also differed in the amount of relevant acoustic-phonetic information. Adults' sensitivity to mispronounced second-syllable onsets also reflected the availability of acoustic-phonetic information. The implications of these findings are discussed in relation to the lexical restructuring hypothesis. (c) 2006 Elsevier Inc. All rights reserved.

Belief in dealing with depression alone: Results from community surveys of adolescents and adults

Background: Community surveys have found that some people believe that it is better to deal with depression alone rather than seek help. However, there has been little research into the characteristics of this group. Methods: Data were drawn from three Australian surveys: (1) a national survey of 1001 adults aged 18+ years; (2) a school survey of 552 students aged 14-16 years from two regions; (3) a survey of 577 young people aged 12-17 years from the Melbourne region. In all three surveys, participants who believed it would be helpful to deal with depression alone were contrasted with those who believed it would be harmful in terms of sociodemographic characteristics, recognition of depression in a vignette, contact with people who experienced depression, beliefs about treatments, beliefs about using substances, beliefs about long-term outcomes, and beliefs about causes. Results: In both adolescents and adults, belief in dealing with depression alone was associated with male gender, less favourable views about mental health professionals, more favourable views about using substances to deal with depression, and a more positive expectation about the outcome if treatment is not sought. Adolescents believing in dealing with depression alone had more favourable views about some potential helpers, such as church workers and pharmacists. In adults, but not adolescents, there was an association with the belief that depression is caused by personal weakness. Limitations: The surveys did not directly ask about reasons for believing that dealing with depression alone would be helpful and did not assess actual help-seeking. Conclusions: Factors encouraging dealing with depression alone are a belief that it is a self-limiting disorder, that substances are an effective way to deal with it and, in adults, that depression is due to personal weakness. Consistent with previous research, males are an important target group for encouraging seeking help to deal with depression. (c) 2006 Elsevier B.V. All rights reserved.

Food habits of young and middle-aged women living outside the capital cities of Australia

Young (18-22 years) and middle-aged (45-49 years) women living in urban and rural areas of New South Wales completed a brief food frequency questionnaire as part of a wider health survey. Urban women in both age groups consumed meat less frequently than women in rural areas; and women in the less populated rural areas were more likely to eat green and yellow vegetables and least likely to eat dried beans. There were few other geographic differences in food habits. Middle-aged women consumed reduced-fat milk, fruit, vegetables, fish, biscuits and cakes significantly more frequently, and rice, pasta, full-cream milk, fried food and take-away food less frequently than younger women. Smokers in both age groups consumed fresh fruit, vegetables and breakfast cereals significantly less frequently than non-smokers, and women with low levels of habitual physical activity consumed fresh fruit and cereals less frequently than more active women. The findings suggest that strategies aimed at changing eating behaviours should be age-group-specific and targeted specifically to smokers and less active women.