1,721,036 research outputs found
Perceptual errors in predicting vehicle approach in typical and atypical populations
Full text linkAs a pedestrian at the roadside, the two most informative cues as to the distance and rate of closure of a vehicle are its optical size and the rate of expansion of the optical image. In addition, the time to arrival of an approaching vehicle can be perceptually estimated by the ratio of these two variables, referred to as tau (Lee, 1976). Sensitivity to optic expansion is critical for collision avoidance and was measured in populations of adults, typically developing children, and in children with Developmental Coordination Disorder (DCD), an idiopathic condition characterised by marked impairments in motor coordination that negatively impact on activities of daily living. A central tendency was found in adults (n = 193) between 18 to 59 years of age to make significant errors in judging the approach rates of two vehicles. Inflated errors were observed in children (n = 136) between 6 to 17 years of age, with decreased sensitivity in the youngest age group (6 to 11 years). Furthermore, a significant decrement was found in children (n = 9) with DCD between 6 to 11 years of age. Across all groups, a systematic vehicle size bias was found, whereby faster small vehicles were perceived as travelling slower than larger vehicles. This pattern of results suggest that in general, observers are not utilising tau in judgments of relative approach rates for speeds typically encountered at the roadside, but instead rely on optical expansion that does not compensate for image size. Errors due to a reliance on optic size were inflated in children with DCD, potentially placing them at significantly greater risk at the roadside. To examine the decreased sensitivity observed in DCD, thresholds for detecting visual looming were measured in children (n = 11) with DCD between 6 to 11 years of age. A significant deficit was found when vehicles were presented in perifoveal vision, whereby children with DCD may perceive vehicles that are 5 seconds away as stationary if they are travelling any faster than ~14 mph. This demonstration of a low-level visual processing deficit could suggest an immaturity in the dorsal stream network and explain some of the difficulties that characterise DCD. Critically, perceptual judgments at the roadside are inextricably linked to the motoric capability of the observer. If a pedestrians crossing time is greater than the time available, collision will occur. Crossing gap thresholds were measured and compared to walking times for a single vehicle approaching at varying speeds. Children (n = 9) with DCD between 6 to 11 years of age left considerably longer temporal crossing gaps than their action capabilities necessitated. However, when children with DCD were presented with multiple vehicles in a virtual reality environment, they accepted crossing gaps at all approach speeds that were shorter than the time it would take them to cross. This suggests that children with DCD may not have the perceptual accuracy to predict their required action gaps in a road crossing situation. One explanation for these findings could be a difference in DCD in how vision is dynamically allocated to facilitate the preparation of goal-directed actions. Dynamic allocation of visual attention was assessed in a series of experiments that measured eye movement latencies and hand movement accuracy in children (n = 5) with DCD between 6 to 11 years of age. Both measures were found to be comparable in DCD with their typically developing peers regardless of task complexity, indicating that the allocation of visual attention is not deficient in children with DCD. The prospective control of movement in our everyday lives is critically depended on estimating the immediacy of approaching objects. Combined, these results indicate that children with DCD may be particularly vulnerable at the roadside due to a visual motion processing deficit, consistent with atypical function across broad neural structures such as the dorsal stream
Investigating the interaction between motor imagery and motor consolidation on motor sequence learning
Full text linkPrevious research suggests prior abilities and rest (a period of consolidation) are critical regarding learning; however, there is a less clear distinction as to the limits of these factors. This study examined the effects of motor imagery and a short motor consolidation period on an individual’s degree of error and reaction times when replicating a piano sequence. Twenty participants took part in an experiment comprising a questionnaire and a motor sequence learning task. The questionnaire assessed bimanual activity and the experiment provided a motor sequence learning task with two rest periods. During the first rest period participants either performed motor imagery to boost their motor learning or did not. During the second rest period, both groups participated in a guided meditation session. It was found that participants’ reaction times when replicating the sequence significantly decreased between each trial, however, the degree of errors made was found to be non-significant between each trial. The bimanual activity was found to be a non-significant covariant in both dependent variables. Future research should re-examine these questions by investigating the duration of the motor imagery task, it is possible that if provided with a longer period to practice motor imagery, the degree of error may decrease further. Additionally, not all participants should take part in the meditative rest period; to further investigate its effect on motor consolidation
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
From Fear to Forgetting: Understanding the Effects of Anxiety on Motor Memory Consolidation
No full textThis study investigates the effects of anxiety on motor memory consolidation, focusing on whether anxiety induced during a short post-practice consolidation period impairs the retention of newly learned motor skills. Using a finger-tapping task, participants were exposed to either a high-anxiety (horror film) or low-anxiety (nature documentary) video during a three-minute consolidation period. State anxiety was measured using the State-Trait Anxiety Inventory (STAI-S) before and after the anxiety manipulation. Results showed that while anxiety was successfully manipulated, anxiety did not significantly affect motor memory consolidation, as measured by the number of correct sequences completed on the finger-tapping task. Further analysis indicated a possible inverted-U relationship between anxiety and memory consolidation, aligning with the Yerkes-Dodson law, where moderate anxiety may enhance consolidation. Despite these insights, the findings were inconclusive due to baseline anxiety differences between groups, highlighting the need for future studies with larger sample sizes and multiple anxiety conditions. This study contributes to understanding the complex relationship between emotional states and memory consolidation, suggesting that moderate anxiety may optimize motor memory processes, although further research is necessary to confirm these findings
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
The importance of primary physical education in England : assessing the acceptability and feasibility of a non-linear approach for parents and teachers
Full text linkCurrently, only about half of children aged 5-7 in the UK meet the recommended World Health Organisation guidelines for physical activity (PA). Given the influence experiences in primary school Physical Education (PE) can have on children's attitude towards PA, ensuring that PE fosters an inclusive and fun environment is important. Play-based PE, an alternative approach to teaching PE, could achieve this. However, little is known about parents' and teachers' perceptions of and receptiveness to play-based PE in England.
This thesis's first aim was to better understand the factors that influence parents to support their child's PA and PE at home. A mixed-methods study design was used; 103 participants completed the questionnaire, and eight were interviewed. The results showed that parents viewed PE and PA positively and were receptive to play-based PE. However, they faced several barriers when supporting their child's PE and PA at home, including time, money, and a lack of communication from the child's school.
The second aim of this thesis was to understand what influences teachers' and teaching assistants’ confidence in teaching/supporting PE. Twenty-three teachers and seven teaching assistants completed a questionnaire. The results showed that just over half did not feel equipped to teach/support inclusive PE, but many felt PE was an important subject and were receptive to play-based PE.
The final aim of this thesis was to assess the acceptability and feasibility of a play-based PE programme in Key Stage One lessons (ages 5-7), using a mixed methods study design. Questionnaires were created using the Capability, Opportunity, Motivation-Behaviour (COM-B) framework; fourteen parents and fifteen teachers completed the pre-intervention questionnaires. Three parents and one teacher completed the post-intervention questionnaires; this data was not used. Four parents and the CPD instructor participated in follow-up interviews. The results showed that parents and teachers needed more physical and social opportunities. The instructor highlighted broader systemic issues with implementing interventions and supporting PE in schools.
The results from these studies provide novel insight into parents' and teachers' receptiveness to play-based PE. Another novel aspect is the ethnically diverse group of parents who highlighted the barriers they currently face when supporting PE at home, making the results more ethnically representative of England's population
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