1,720,985 research outputs found
Perceptual-cognitive processes in sport: the role of the sports task on quiet eye
Full text linkThe present doctoral thesis dealt with a relevant perceptual-cognitive factor within the sports domain, called "quiet eye" (QE). The literature on this topic described the QE as an ocular fixation that could be considered a hallmark of superior expertise and performances across several sports requiring aiming tasks. Indeed, several characteristics of the QE (e.g., earlier onset and a longer quiet eye duration) correlate with greater athletes' expertise and best performances. In addition, QE training positively affects task performance.
Despite 25 years of research on QE, there is still no agreement about the QE function that could explain the relationship between this fixation and the highest levels of sports expertise and performance.
On this basis, the present doctoral thesis aimed to comprehend, through four different studies, the QE underlying functions by exploring novel aiming tasks and manipulating well-known sports tasks in the QE literature.
On the whole, the findings of the four studies suggest that the acquisition of environmental visual information through the QE occurs at different times during the ongoing action, according to the kinematical and timing specificity of the task. Therefore, the difference in QE timing between tasks should represent a different underlying function.
The results reported in the present doctoral thesis seem consistent with the speculation of Lebeau et al. (2016), who suggested that the specific role of the QE could depend on the type of sports task.
Besides the research value, the findings of the present doctoral thesis have important implications from an applied point of view. The literature showed that QE training protocols permit novices the acquisition of a "like an expert" gaze behavior. On the one hand, the results of the present doctoral thesis stretched the relevance of establishing a QE prototype specific to the task before implementing any QE training protocols to non-experts, following Vickers's (2016) guidelines. On the other hand, the results reported suggest that the QE training protocols should also be applied to expert athletes to permit the transfer of the QE characteristics to complex game conditions, allowing athletes to perform successfully, regardless of the trickiness of the sport situation
Cerebellar contribution to spatial event processing: Do spatial procedures contribute to formation of spatial declarative knowledge?
No full textSpatial knowledge of an environment involves two distinct competencies: declarative spatial knowledge, linked to where environmental cues are and where the subject is with respect to the cues, and, at the same time, procedural spatial knowledge, linked to how to move into the environment. It has been previously demonstrated that hemicerebellectomized (HCbed) rats are impaired in developing efficient exploration strategies, but not in building spatial maps or in utilizing localizing cues. The aim of the present study was to analyse the relationships between spatial procedural and declarative knowledge by using the open field test. HCbed rats have been tested in two different protocols of the open field task. The results indicate that HCbed animals succeeded in moving inside the arena, in contacting the objects and in habituating to the new environment. However, HCbed animals did not react to environmental changes, when their impaired explorative pattern was inappropriate to the environment, suggesting that they were not able to represent a new environment because they were not able to explore it appropriately. Nevertheless, when their altered procedures were favoured by object arrangement, they detected environmental changes as efficiently as did normal rats. This finding suggests that no declarative spatial learning is possible without appropriate procedural spatial learning.Spatial knowledge of an environment involves two distinct competencies: declarative spatial knowledge, linked to where environmental cues are and where the subject is with respect to the cues, and, at the same time, procedural spatial knowledge, linked to how to move into the environment. It has been previously demonstrated that hemicerebellectomized (HCbed) rats are impaired in developing efficient exploration strategies, but not in building spatial maps or in utilizing localizing cues. The aim of the present study was to analyse the relationships between spatial procedural and declarative knowledge by using the open field test. HCbed rats have been tested in two different protocols of the open field task. The results indicate that HCbed animals succeeded in moving inside the arena, in contacting the objects and in habituating to the new environment. However, HCbed animals did not react to environmental changes, when their impaired explorative pattern was inappropriate to the environ
Is the cerebellum involved in the visuo-locomotor associative learning?
No full textThe role played by cerebellar circuits in visuo-motor associative learning is still unclear. The aim of the present study was to analyse cerebellar involvement using a visuo-locomotor associative learning paradigm that did not require spatial competences. Hemicerebellectomized (HCbed) and Control rats were tested in a visual discrimination task. First, both groups of rats had to learn that a reward was associated with an object that had a specific colour and shape (Experiment 1). Then, the shape but not the colour of the rewarded object was modified to verify whether the animals were able to transfer the rule of rewarding or whether they had to acquire a new association (Experiment 2). In the first sessions of the Experiment 1, HCbed animals displayed a tendency toward peripheral circling and a delay of about three sessions in reaching the criterion of correct choices compared to Controls. This delay has to be correlated to the need to overcome the procedural impairment elicited by the HCb. Once the HCbed animals put efficient procedural abilities into action, they exhibited a similar increase in percentages of successes from the fourth session onward as Controls. The results of Experiment 2 confirm the intact associative abilities of HCbed animals, as demonstrated by their progressive increase in successful associative responses, which, at the end of the transfer phase, were not significantly different from those of the Control group. The present findings indicate that the presence of a cerebellar lesion delays but does not prevent visuo-locomotor associative learning and that stimulus generalisation is performed without difficulty even in the presence of a cerebellar lesion. (C) 2007 Elsevier B.V. All rights reserved.The role played by cerebellar circuits in visuo-motor associative learning is still unclear. The aim of the present study was to analyse cerebellar involvement using a visuo-locomotor associative learning paradigm that did not require spatial competences. Hemicerebellectomized (HCbed) and Control rats were tested in a visual discrimination task. First, both groups of rats had to learn that a reward was associated with an object that had a specific colour and shape (Experiment 1). Then, the shape but not the colour of the rewarded object was modified to verify whether the animals were able to transfer the rule of rewarding or whether they had to acquire a new association (Experiment 2). In the first sessions of the Experiment 1, HCbed animals displayed a tendency toward peripheral circling and a delay of about three sessions in reaching the criterion of correct choices compared to Controls. This delay has to be correlated to the need to overcome the procedural impairment elicited by th
NMDA receptor activity in learning spatial procedural strategies II. The influence of cerebellar lesions
No full textExperimental data support the involvement of cerebellar circuits in the acquisition of spatial procedural competences. Since the ability to acquire new procedural competences is lost when cerebellar regions are lesioned or when NMDA receptor activity is blocked, we analyzed whether the learning of explorative strategies is affected by blocking NMDA receptor activity in the presence of cerebellar lesions. To this aim, the NMDA receptor antagonist (CGS 19755, 7 mg/kg) was administered i.p. to un-lesioned rats, or rats subjected to total ablation of the cerebellum or to hemicerebellectomy. CGS 19755 and cerebellectomy both produced water maze behavior characterized by circling. Administration of CGS 19755 did not modify the Morris Water Maze (MWM) peripheral circling behavior of cerebellectomized animals. Circling was the dominant strategy of hemicerebellectomized animals in the absence of drugs. However, increasingly compulsive circling was observed under the action of CGS 19755. Circling was not observed if the drug-treated animals (un-lesioned or lesioned) had been previously trained. In conclusion, the NMDA antagonist caused severe impairment in the acquisition of spatial procedures, thus mimicking the consequences of cerebellar ablation on spatial procedural learning. Based on the present findings, we hypothesize that cerebellar NMDA receptor activity is involved in the acquisition of procedural spatial competence. (c) 2006 Published by Elsevier Inc.Experimental data support the involvement of cerebellar circuits in the acquisition of spatial procedural competences. Since the ability to acquire new procedural competences is lost when cerebellar regions are lesioned or when NMDA receptor activity is blocked, we analyzed whether the learning of explorative strategies is affected by blocking NMDA receptor activity in the presence of cerebellar lesions. To this aim, the NMDA receptor antagonist (CGS 19755, 7 mg/kg) was administered i.p. to un-lesioned rats, or rats subjected to total ablation of the cerebellum or to hemicerebellectomy. CGS 19755 and cerebellectomy both produced water maze behavior characterized by circling. Administration of CGS 19755 did not modify the Morris Water Maze (MWM) peripheral circling behavior of cerebellectomized animals. Circling was the dominant strategy of hemicerebellectomized animals in the absence of drugs. However, increasingly compulsive circling was observed under the action of CGS 19755. Circli
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
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
Social withdrawal in early childhood: shyness, unsociability and social avoidance
Full text linkTheoretical and empirical literature extensively underline that both the quantity and the quality of peer social interactions and relationships are important components of human life and fundamental contributors to positive children’s social, emotional, and cognitive development (Gazelle, & Ladd, 2003; Ladd, & Burgess, 1999). From early in childhood, establishing and being involved in positive social relationships influence long-term trajectories of well-being, health, and positive adjustment (Rubin, Bukowski, & Parker, 2006; Umberson & Montez, 2015). A lack in the quantity or in the quality of social interactions may negatively alter or impair children’s socio-emotional development (Edwards, & Hans, 2015; Ladd, & Burgess, 1999). Accordingly, children who engage in comparatively infrequent social interactions may ‘miss out’ on these benefits, with potential implications for their long-term socio-emotional adjustment (Caspi, Harrington, Moffitt, Milne, & Poulton, 2006; Kopala-Sibley, & Klein, 2017; Rubin, Coplan, & Bowker, 2009). Nevertheless, some children tend to withdraw from the opportunity to play or socialize with others. The term used to define the process of removing oneself from opportunities for social interactions is social withdrawal (Coplan, & Rubin, 2010; Rubin, et al., 2009). In recent years, researchers have proposed increasingly complex models to describe social withdrawal, shifting from a unidimensional to a multidimensional approach that reflects a range of underlying emotional and motivational substrates (Coplan, Ooi, Xiao, & Rose-Krasnor, 2018). As a result, contemporary researchers now conceptualize subtypes of social withdrawal that 8 can be detected during childhood, that may have different psychological meanings, and appear to be related to different outcomes (e.g., Asendorpf, 1990; Coplan, Ooi & Nocita, 2015; Li et al., 2016). Despite growing interest in the study of social withdrawal in recent years (see Coplan, Ooi, & Baldwin, 2019; Coplan et al., 2018; Sette, Baldwin, Zava, Baumgartner, & Coplan, 2019; Sette, Hipson, Zava, Baumgartner, & Coplan, 2018), to date it remains an underexplored aspect of children's development that still merits further empirical investigation. In this regard, the present dissertation aimed to investigate still unexplored facets of social withdrawal in preschool-aged children. In the first section of this dissertation, the theoretical aspects of social withdrawal will be discussed, with a main focus on definitions, functions, and implications for young children’s emotional development and social adjustment. In the second section, three studies will be presented: Study 1. Shyness, Unsociability and Social Avoidance. Social withdrawal from young children's perspective: preschool children’s understanding and beliefs about hypothetical socially withdrawn peers. Study 2. Shyness and Unsociability. Social withdrawal and protective factors: the positive role of peer acceptance for shy and unsociable preschool children. Study 3. Shyness. Social withdrawal moral emotion: Shyness and Empathy in Early Childhood: Examining Links between Feelings of Empathy and Empathetic Behavior
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
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