首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
ObjectivesWearable actimetry devices are used increasingly in cohort and cross-sectional studies to assess physical activity (PA) behaviour objectively. Thus far, the medical relevance of distinct PA groups, as identified by using new methods of sensor data analysis, remains unclear. The objective of this research paper is to evaluate whether such PA groups differ in commonly accepted health risk parameters.MethodsPA sensor data and corresponding outcome data of the NHANES 2005–06 study were obtained. Data pre-processing included elimination of potential outliers, data splitting and the computation of PA parameters, including a novel regularity measure. PA groups were identified using the x-Means clustering algorithm, and groups were evaluated for differences in CRP, BMI and HDL.ResultsData sets of 7334 NHANES participants were analysed, and four distinct PA groups were identified. Statistically significant group differences were found for CRP and BMI (p < 0.001), but not for HDL (p = 0.67).ConclusionsPA groups derived from objective accelerometer mass data differ in exemplary health-related outcome parameters. The novel PA regularity measure is of particular interest and may become part of future PA assessments, especially when regarding low-intensity, short-lived PA events. Further research in pattern recognition methods and analytic algorithms for PA data from current multi-sensing devices is necessary.  相似文献   

2.
This study examines time‐limited therapy in a Community Mental Health Team (CMHT) setting. This work is a key tension for CMHTs who are under pressure to focus on clients with a serious mental illness as a priority as opposed to clients who might be deemed the ‘psychologically distressed’. The development of CMHTs in the UK is described. Limited research on time‐limited therapy in a CMHT setting is identified. Results suggest that time‐limited therapy has a positive impact on the mental health needs of clients referred to a CMHT by GPs. It is concluded that it is appropriate to justify the use of time‐limited therapy in a CMHT‐based setting. Suggestions for further research are made.  相似文献   

3.
In the last years, several researchers measured different recognition rates with different artificial neural network (ANN) techniques on public data sets in the human activity recognition (HAR) problem. However an overall investigation does not exist in the literature and the efficiency of complex and deeper ANNs over shallow networks is not clear. The purpose of this paper is to investigate the recognition rate and time requirement of different kinds of ANN approaches in HAR. This work examines the performance of shallow ANN architectures with different hyper-parameters, ANN ensembles, binary ANN classifier groups, and convolutional neural networks on two public databases. Although the popularity of binary classifiers, classifier ensembles and deep learning have been significantly increasing, this study shows that shallow ANNs with appropriate hyper-parameters in combination with extracted features can reach similar or higher recognition rate in less time than other artificial neural network methods in HAR. With a well-tuned ANN we outperformed all previous results on two public databases. Consequently, instead of the more complex ANN techniques, the usage of simple ANN with two or three layers can be an appropriate choice for activity recognition.  相似文献   

4.
Human action recognition in videos is a tough task due to the complex background, geometrical transformation and an enormous volume of data. Hence, to address these issues, an effective algorithm is developed, which can identify human action in videos using a single decisive pose. To achieve the task, a decisive pose is extracted using optical flow, and further, feature extraction is done via a two-fold transformation of wavelet. The two-fold transformation is done via Gabor Wavelet Transform (GWT) and Ridgelet Transform (RT). The GWT produces a feature vector by calculating first-order statistics values of different scale and orientations of an input pose, which have robustness against translation, scaling and rotation. The orientation-dependent shape characteristics of human action are computed using RT. The fusion of these features gives a robust unified algorithm. The effectiveness of the algorithm is measured on four publicly datasets i.e. KTH, Weizmann, Ballet Movement, and UT Interaction and accuracy reported on these datasets are 96.66%, 96%, 92.75% and 100%, respectively. The comparison of accuracies with similar state-of-the-arts shows superior performance.  相似文献   

5.
Limited research has explored the factors that promote initiation of adapted physical activity (PA) for individuals with acquired disabilities. Thus, the current paper explores the role of social support in initiating PA among this population. Participants consisted of civilians (n = 15; age: 19–73 years) and military personnel (n = 18; age: 30–68 years) with acquired disabilities (e.g., spinal cord injuries, limb amputation). Two semi-structured interviews were conducted exploring perceptions and participation of adapted sport and PA. An inductive thematic analysis was performed to identify patterns relating to social support and PA initiation. Four social support networks were identified — family, peers, coaches, and community. Findings were presented using creative non-fiction. The results illustrate the complexity and critical value of social support in adapted PA, highlight the nuances that arise in the availability and expression of social, and provides the foundation for further exploration of the significance of social support for people with acquired disabilities.  相似文献   

6.
Many studies in animals and humans suggest that sleep facilitates learning, memory consolidation, and retrieval. Moreover, sleep deprivation (SD) incurred after learning, impaired memory in humans, mice, rats, and hamsters. We investigated the importance of sleep and its timing in an object recognition task in OF1 mice subjected to 6h SD either immediately after the acquisition phase (0-6 SD) or 6h later (7-12 SD), and in corresponding undisturbed controls. Motor activity was continuously recorded with infrared sensors. All groups explored two familiar, previously encountered objects to a similar extent, both at the end of the acquisition phase and 24h later during the test phase, indicating intact familiarity detection. During the test phase 0-6 SD mice failed to discriminate between the single novel and the two familiar objects. In contrast, the 7-12 SD group and the two control groups explored the novel object significantly longer than the two familiar objects. Plasma corticosterone levels determined after SD did not differ from time-matched undisturbed controls, but were significantly below the level measured after learning alone. ACTH did not differ between the groups. Therefore, it is unlikely that stress contributed to the memory impairment. We conclude that the loss of sleep and the activities the mice engaged in during the SD, impaired recognition memory retrieval, when they occurred immediately after acquisition. The delayed SD enabled memory consolidation during the 6h when the mice were allowed to sleep, and had no detrimental effect on memory. Neither SD schedule impaired object familiarity processing, suggesting that only specific cognitive abilities were sensitive to the intervention. Sleep may either actively promote memory formation, or alternatively, sleep may provide optimal conditions of non-interference for consolidation.  相似文献   

7.
The purpose of this document is to offer a combined approach in biometric analysis field, integrating some of the most known techniques using ears to recognize people. This study uses Hausdorff distance as a pre-processing stage adding sturdiness to increase the performance filtering for the subjects to use it in the testing process. Also includes the Image Ray Transform (IRT) and the Haar based classifier for the detection step. Then, the system computes Speeded Up Robust Features (SURF) and Linear Discriminant Analysis (LDA) as an input of two neural networks to recognize a person by the patterns of its ear. To show the applied theory experimental results, the above algorithms have been implemented using Microsoft C#. The investigation results showed robustness improving the ear recognition process.  相似文献   

8.
Hills and Lewis (2006) reduced White participants’ own-race bias (ORB) in face recognition by training them to attend to features critical for Black faces (lower portion of the face). Here, the ORB was investigated following a brief fixation cross either in the upper portion of the face (critical for White faces) or the lower portion of the face. Results showed that when the cross preceded the lower portion of the face, Black faces were recognized more accurately than White faces and vice versa when it preceded the upper portion of the face. A second experiment demonstrated that this effect disappears if the participants are forced to delay their responses by 4 s. These results suggest that an immediate attentional mechanism can attenuate the ORB when immediate attention is paid to diagnostic features but this can be overridden with increased time spent viewing faces.  相似文献   

9.
本研究通过一个自我参照效应范式实验探讨了“熟人”差序格局是否体现在记忆再认中。要求被试在由感情深浅与工具性目的有无的组合构建的“熟人”差序格局中填入关系由近至远的四个对象人物,并以此为参照进行人格形容词再认。结果表明由近及远四个圈层分别主要由深/有、深/无、浅/有、浅/无组合的对象人物构成,且亲密度逐层下降,感情比工具性目的在其中的影响更大。再认率与R判断率中较熟悉者(主要为前三圈)高于仅相识者(主要为第四圈)、而较熟悉者的前三圈间无显著差异。由于交往频率等的影响在记忆效果上仅呈现出“较熟悉者——仅相识者”的二分格局。  相似文献   

10.
This study investigated the ability of a captive chimpanzee (Pan troglodytes) to recognise when he is being imitated. In the experimental condition of test 1a, an experimenter imitated the postures and behaviours of the chimpanzee as they were being displayed. In three control conditions the same experimenter exhibited (1) actions that were contingent on, but different from, the actions of the chimpanzee, (2) actions that were not contingent on, and different from, the actions of the chimpanzee, or (3) no action at all. The chimpanzee showed more "testing" sequences (i.e., systematically varying his actions while oriented to the imitating experimenter) and more repetitive behaviour when he was being imitated, than when he was not. This finding was replicated 4 months later in test 1b. When the experimenter repeated the same actions she displayed in the experimental condition of test 1a back to the chimpanzee in test 2, these actions now did not elicit those same testing sequences or repetitive behaviours. However, a live imitation condition did. Together these results provide the first evidence of imitation recognition in a nonhuman animal.  相似文献   

11.
Hidden Markov models (HMMs) have been successful for modelling the dynamics of carefully dictated speech, but their performance degrades severely when used to model conversational speech. Since speech is produced by a system of loosely coupled articulators, stochastic models explicitly representing this parallelism may have advantages for automatic speech recognition (ASR), particularly when trying to model the phonological effects inherent in casual spontaneous speech. This paper presents a preliminary feasibility study of one such model class: loosely coupled HMMs. Exact model estimation and decoding is potentially expensive, so possible approximate algorithms are also discussed. Comparison of one particular loosely coupled model on an isolated word task suggests loosely coupled HMMs merit further investigation. An approximate algorithm giving performance which is almost always statistically indistinguishable from the exact algorithm is also identified, making more extensive research computationally feasible.  相似文献   

12.
Executive functions (EF) are crucial for the athletes’ success, and they are even more essential in open skill sports (e.g. volleyball and football). In these sports, due to continuously changing conditions, goal-directed behaviours need to be repeatedly adjusted and corrected. One of the most important EF is the ability to continuously switch between two different tasks being required in a random sequence. We used a task-switching protocol in elite volleyball athletes, usually playing different roles, with the aim of evaluating if each role is characterized by specific switching abilities. On the basis of the specific competences requested by the game, thirty-six elite volleyball athletes were assigned to three groups: Strikers, Defenders and Mixed. Each player completed a customized sport-specific task-switching paradigm. Data evidenced that each role has specific characteristics. In Reaction Times, the Strikers were the fastest to answer to stimuli, while the Defender group provided a worse performance, particularly when defensive actions, that probably require more cognitive elaboration, had to be processed. Different effects emerged by the Errors. In fact, the Mixed group, which was the one with more expertise, appeared to be more accurate in the responses.Although preliminary, these results showed a minimal degree of cognitive flexibility for highly specialized Strikers and a maximum level for Mixed, allowing thus to highlight specific profiles of athletes. Data observed indicate the possibility to develop a test assessing the executive domain during the recruitment in a team, revealing a useful tool for choosing the most suitable role.  相似文献   

13.
情绪韵律识别是从声学线索变化中提取情绪信息,进而推断他人情绪状态的过程。情绪韵律识别缺陷是孤独症谱系障碍者的一种常见表现,此缺陷会受到情绪韵律强度、字面语义、情景语境、心理声学能力和共患疾病的影响。目前,该人群情绪韵律识别缺陷的原因探析集中于心智化能力不足、社会动机缺失和经验匮乏假说等。孤独症谱系障碍者情绪韵律识别的神经机制研究主要集中于与健康人群的比较,相关发现包括情绪韵律识别的右半球优势效应、局部脑区激活增多、大脑网络连接不足和早期注意模式异常。未来,应该进一步提高实验范式的生态效度,注重孤独症个体差异因素,整合相关理论解释,并开发有效的测评工具和干预策略。  相似文献   

14.
The present research investigated whether assessing adolescent elite athletes’ motivational profiles at the beginning of the season would allow us to predict their subsequent performance over the course of a competitive season. In two studies, athletes completed the French version of the Sport Motivation Scale (Brière et al., Int J Sport Psychol 26:465–489, 1995) at the beginning of the season. Objective levels of performance were recorded for the following season, as well as for the season prior to questionnaire completion. In Study 1, the sample comprised a total of 170 French junior national tennis players (M = 13.42 years). Results revealed the presence of a four-cluster solution, reflecting different levels of autonomous and controlled motivations. Results revealed that controlling for past performance, athletes with the least self-determined motivational profile obtained lower levels of subsequent tennis performance than those in the three other (more self-determined motivational) clusters. In Study 2, there were a total of 250 French junior national fencers aged 15 years. Results revealed a three-cluster solution very similar to that of Study 1. In addition, in line with Study 1, results revealed that the least self-determined motivational profile led to the lowest level of performance. Overall, these findings suggest that cluster analysis is useful in the understanding of the complex relationship between motivation and performance in elite sport.
Nicolas GilletEmail:
  相似文献   

15.
We examined whether listeners use acoustic correlates of voicing to resolve lexical ambiguities created by whispered speech in which a key feature, the voicing, is missing. Three associative priming experiments were conducted. The results showed a priming effect with whispered primes that included an intervocalic voiceless consonant (/petal/ “petal”) when the visual targets (FLEUR “flower”) were presented at the offset of the primes. A priming effect emerged with whispered primes that included a voiced intervocalic consonant (/pedal/ “pedal”) when the delay between the offset of the primes and the visual targets (VELO “bike”) was increased by 50 ms. In none of the experiments, the voiced primes (/pedal/) facilitated the processing of the targets (FLEUR) associated with the voiceless primes (/petal/). Our results suggest that the acoustic correlates of voicing are used by listeners to recover the intended words. Nonetheless, the retrieval of the voiced feature is not immediate during whispered word recognition.  相似文献   

16.
In opaque orthographies, the activation of orthographic and phonological codes follows distinct time courses during visual word recognition. However, it is unclear how orthography and phonology are accessed in more transparent orthographies. Therefore, we conducted time course analyses of masked priming effects in the transparent Dutch orthography. The first study used targets with small phonological differences between phonological and orthographic primes, which are typical in transparent orthographies. Results showed consistent orthographic priming effects, yet phonological priming effects were absent. The second study explicitly manipulated the strength of the phonological difference and revealed that both orthographic and phonological priming effects became identifiable when phonological differences were strong enough. This suggests that, similar to opaque orthographies, strong phonological differences are a prerequisite to separate orthographic and phonological priming effects in transparent orthographies. Orthographic and phonological priming appeared to follow distinct time courses, with orthographic codes being quickly translated into phonological codes and phonology dominating the remainder of the lexical access phase.  相似文献   

17.
Hills and Lewis (2011) have demonstrated that the own-race bias in face recognition can be reduced or even removed by guiding participants' attention and potentially eye movements to the most diagnostic visual features. Using the same old/new recognition paradigm as Hills and Lewis, we recorded Black and White participants' eye movements whilst viewing Black and White faces following fixation crosses that preceded the bridge of the nose (between the eyes) or the tip of the nose. White faces were more accurately recognized when following high fixation crosses (that preceded the bridge of the nose) than when following low fixation crosses. The converse was true for Black faces. These effects were independent of participant race. The fixation crosses attracted the first fixation but had less effect on other eye-tracking measures. Furthermore, the location of the first fixation was predictive of recognition accuracy. These results are consistent with an attentional allocation model of the own-race bias in face recognition and highlight the importance of the first fixation for face perception (cf. Hsiao & Cottrell, 2008).  相似文献   

18.
The present paper investigated recognition errors in affective judgement of facial emotional expressions. Twenty-eight females and sixteen males participated in the study. The results showed that in both males and females emotional displays could be correctly classified, but females had a higher rate of correct classification; males were more likely to have difficulty distinguishing one emotion from another. Females rated emotions identically regardless of whether the emotion was displayed by a male or female face. Furthermore, the two-factor structure of emotion, based on a valence and an arousal dimension, was only present for female subjects. These results further extend our knowledge about gender differences in affective information processing.  相似文献   

19.
Objective: A common barrier to exercise is a perceived lack of time. The current pilot study examined the effects of an implementation intention intervention to enhance exercise self-efficacy, increase confidence to exercise when facing time constraints, and increase physical activity in middle-aged adults (n?=?63, aged 35–69). Design: Participants received a pedometer (Fitbit) to objectively measure activity and were randomly assigned to either a control or intervention condition. After a 1-week baseline, the intervention condition received instructions to plan how, where, and when they would add steps to their daily routine to meet their step goal, using personalised schedules and maps. Both groups were contacted nightly via email. Main Outcome Measures: Physical activity (steps and time spent in moderate-to-vigorous activity), goal achievement, exercise self-efficacy, time-relevant exercise self-efficacy and affect. Results: Compared to the control, the intervention condition significantly increased in steps, time spent in moderate-to-vigorous activity, and time-relevant exercise self-efficacy. Goal achievement was related to greater time-relevant exercise self-efficacy and more positive affect at the daily level. Conclusion: Findings suggest that the personalised planning intervention increased physical activity and confidence in achieving physical activity goals under time constraints. Avenues for future directions, especially for producing more sustained effects, are discussed.  相似文献   

20.
The Implicit Association Test (IAT) is the most popular indirect measure of attitudes in social psychology. Rothermund and Wentura (2001, 2004) suggested that artifacts such as salience asymmetries are a source of compatibility effects in the IAT, and, therefore, the IAT does not necessarily measure attitude. They claim that salience asymmetries correspond with visual search asymmetries, such that the stimulus categories that are more quickly detected in a visual search task are also compatible in the IAT. We propose that processing fluency is a more reliable indicator of salience asymmetries in the IAT than are visual search asymmetries. To test this hypothesis, we set processing fluency in opposition to visual search asymmetry to see which variable better predicted IAT effects. In one pair of categories, the category that was more quickly detected in visual search was also more fluently processed in a binary classification task. In a second pair of categories, the category that was more quickly detected in visual search was the less fluently processed category. Across four experiments, we demonstrated that compatibility effects in the IAT corresponded with differences in processing fluency between categories, rather than with visual search asymmetries.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号