Association Between Gait and Dual Task With Cognitive Domains in Older People With Cognitive Impairment

The authors investigated whether impaired gait and dual-task performances are associated with specific cognitive domains among older people with preserved cognition (PC), mild cognitive impairment (MCI), and mild Alzheimer's disease (AD). The sample comprised 40 older adults with PC, 40 with MCI, and 38 with mild AD. The assessment consisted of gait (measured by 10-m walk test and Timed Up and Go Test [TUGT]), dual task (measured by TUGT associated with a cognitive-motor task of calling a phone number), and cognition (domains of the Addenbrooke Cognitive Examination–Revised and Frontal Assessment Battery [FAB]). For data analysis, the Pearson product-moment correlation and the backward stepwise linear regression were conducted. Language, fluency, and visuospatial domains predicted the 10-m walk test measure specifically in PC, MCI, and AD groups. Only the visuospatial domain was independently associated with the TUGT measure in the MCI and AD groups. FAB score, language domain, and FAB score and fluency domain were the strongest predictors for the isolated cognitive-motor task measure in the PC, MCI, and AD groups, respectively. The visuospatial domain was independently associated with the dual-task test measure in all 3 groups. The study findings demonstrate the influence of specific cognitive domains in daily mobility tasks in people with different cognitive profiles.     

Can pupillometry index auditory attentional capture in contexts of active visual processing?

The rare presentation of a sound that deviates from the auditory background tends to capture attention, which is known to impede cognitive functioning. Such disruption is usually measured using performance on a concurrent visual task. Growing evidence recently showed that the pupillary dilation response (PDR) could index the attentional response triggered by a deviant sound. Given that the pupil diameter is sensitive to several vision-related factors, it is unclear whether the PDR could serve to study attentional capture in such contexts. Hence, the present study aimed at verifying whether the PDR can be used as a proxy for auditory attentional capture while a visual serial recall task (Experiment 1) or a reading comprehension task (Experiment 2) – respectively producing changes in luminance and gaze position – is being performed. Results showed that presenting a deviant sound within steady-state standard sounds elicited larger PDRs than a standard sound. Moreover, the magnitude of these PDRs was positively related to the amount of performance disruption produced by deviant sounds in Experiment 1. Performance remained unaffected by the deviants in Experiment 2, thereby implying that the PDR may be a more sensitive attention-capture index than behavioural measures. These results suggest that the PDR can be used to assess attentional capture by a deviant sound in contexts where the pupil diameter can be modulated by the visual environment.     

The Cognitive Demands of Gait Retraining in Runners: An EEG Study

Abstract

High impact forces during running have been associated with tibial stress injuries. Previous research has demonstrated increasing step rate will decrease impact forces during running. However, no research has determined the cognitive demand of gait retraining. The primary purpose was to determine the cognitive demand and effectiveness of field-based gait retraining. We hypothesized that in-field gait retraining would alter running mechanics without increasing cognitive workload as measured by EEG following learning. Runners with a history of tibial injury completed a gait retraining protocol which included a baseline run, retraining phase, practice phase, and re-assessment following retraining protocol. Results demonstrated an increase in the theta, beta, and gamma power within prefrontal cortex during new learning and corresponding return to baseline following skill acquisition and changes across alpha, beta, gamma, mu, and theta in the motor cortex (p < .05). In the midline superior parietal cortex, spectral power was greater for theta activity during new learning with a corresponding alpha suppression. Overall, the results demonstrated the use of EEG as an effective tool to measure cognitive demand for implicit motor learning and the effectiveness of in-field gait retraining.     

Sample size and bentler and Bonett's nonnormed fit index

Bentler and Bonett's nonnormed fit index is a widely used measure of goodness of fit for the analysis of covariance structures. This note shows that contrary to what has been claimed the nonnormed fit index is dependent on sample size. Specifically for a constant value of a fitting function, the nonnormed index is inversely related to sample size. A simple alternative fit measure is proposed that removes this dependency. In addition, it is shown that this new measure as well as the old nonnormed fit index can be applied to any fitting function that measures the deviation of the observed covariance matrix from the covariance matrix implied by the parameter estimates for a model.     

城市老年人生活满意度及其影响因素的研究

生活满意指数是衡量老年人心理健康状况的一项重要指标,而许多因素都可能会对老年人的生活满意指数产生影响。我们采用生活满意指数A(LSIA)量表对355名城市老年人进行了有关研究,结果表明:城市老年人的LSIA平均得分为13.07±3.43(M±SD);老年人中对经济状况满意、对个人健康状况自我评价好、抑郁症状轻、原无职业及有较多亲密朋友者,其生活满意指数就高,反之则低。     

Open-field nidus and pullusindices in Mus Musculus L.

Swiss albino mice ( Mus Musculus L. ) were studied in an open field (OF). The question whether laboratory rodents were more attracted to a nest equipped with familiar odoriferous cues from the home-cage bedding or to signals of an unfamiliar newborn pup inserted in the OF was addressed. The results of the three quantitatively recorded OF behaviors, ambulation, retrieval and radial latency , indicated that in females both ambulation and retrieval were enhanced by the presence of a pup in a nestless field; in males locomotion was suppressed by a nest in a pupless OF. In the case of both sexes radial latency was determined by the OF position of a nest. A comparison between the two qualitative assessments, the nidus and pullus indices, yielded that the sex of the adult and the OF positions of both targets equally impacted attraction towards both nest and pup.     

Equivalent models in covariance structure analysis

Defining equivalent models as those that reproduce the same set of covariance matrices, necessary and sufficient conditions are stated for the local equivalence of two expanded identified modelsM ₁ andM ₂ when fitting the more restricted modelM ₀. Assuming several regularity conditions, the rank deficiency of the Jacobian matrix, composed of derivatives of the covariance elements with respect to the union of the free parameters ofM ₁ andM ₂ (which characterizes modelM ₁₂), is a necessary and sufficient condition for the local equivalence ofM ₁ andM ₂. This condition is satisfied, in practice, when the analysis dealing with the fitting ofM ₀, predicts that the decreases in the chi-square goodness-of-fit statistic for the fitting ofM ₁ orM ₂, orM ₁₂ are all equal for any set of sample data, except on differences due to rounding errors.This research was supported by the Foundation of Social-Cultural Sciences which is subsidized by the Dutch Scientific Organization (N.W.O.) under project number 500-278-003. The author wishes to thank Anne Boomsma, Ivo Molenaar, Albert Satorra, and Tom Snijders for their stimulating and crucial comments during the research, and the Editor, Paul Bekker, Henk Broer, and anonymous reviewers for their helpful suggestions.     

运动空间定向判断中的方向偏差及飞行惯性

模拟客体起飞和降落运动,探讨飞行场景中不同运动位置、不同意义客体和运动方向下个体运动空间定向判断能力。结果表明：(1)对降落运动轨迹的判断正确率显著低于起飞运动;(2)无意义客体偏高轨迹的判断正确率显著小于偏低轨迹,表现出方向偏差;(3)飞行场景影响方向偏差的表现形式,当飞机降落运动时,易将偏低路径判断为与预设轨迹相同,而飞机起飞运动时,易将偏高路径判断为相同,表明降落时飞机被知觉为会向斜下方越飞越低,而起飞时飞机会向斜上方越飞越高,表现出飞行惯性。结论：运动空间定向判断受到重力表征及个体知识经验等共同影响,具有认知可渗透性。