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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
EFFECTS OF PEER SOCIAL SUPPORT ON EFFICACY PERCEPTIONS AND PHYSICAL PERFORMANCE IN YOUTH
Get PDFSocial interactions contribute to psychosocial and physical outcomes in youth sport and physical activity settings. Social interactions (e.g., peer social support) are theorized to inform relation-inferred self-efficacy (RISE) and, in turn, influence self-efficacy. When performing tasks that require high physical demand, prior cognitive exertion leads to decreases in self-efficacy and physical performance. The primary purpose of this study was to examine the effect of peer social support on RISE, task self-efficacy, and physical endurance performance in youth, and to explore intermediary pathways between these variables. The secondary purpose was to examine motor coordination as a moderating variable. Youth (N = 84, Mage = 10.43 1.26) were randomly assigned to dyads and, subsequently, to either a peer social support group or a control group. All participants completed two endurance handgrip squeezes at 30% of their maximal voluntary contraction force separated by a cognitively demanding task (Stroop task). In the peer social support group, participants exchanged supportive words of encouragement prior to the second endurance handgrip squeeze, while those in the control group performed the task without prior interaction with their partner. Participants in the peer social support condition reported higher RISE (d = 0.86, p < .001) and greater improvements in physical endurance performance (d = 0.58, p < .01) compared to the control group; however, differences in task self-efficacy were non-significant (d = 0.26, p = .24). Contrary to hypotheses, there was no indirect effect of peer social support on endurance performance change through RISE and self-efficacy. In addition, there was no evidence of a moderating effect of motor coordination. Although, the mechanisms through which peer social support positively impact physical performance remain unclear, results suggest providing peer social support prior to a challenging physical task is associated with more positive RISE perceptions and improved physical performance.ThesisMaster of Science (MSc
Mental Fatigue, Motivation, and Physical Activity Decision-Making
Get PDFPrevious research has demonstrated mental fatigue impairs subsequent physical performance, however, current understanding of the role of mental fatigue on physical activity and exercise decision-making is limited for several reasons. For example, research examining the relation between mental fatigue and physical activity behaviors has relied on experimental methods and physical tasks performed in controlled laboratory settings with limited applicability to everyday experiences. In addition, direct measures of motivation commonly used within the literature are subject to biases, highlighting the importance of alternate methods for assessing motivation using indirect measures. To address these limitations, methods with stronger ecological validity are needed to extend research from controlled, experimental settings to measure mental fatigue in naturalistic settings and provide a diverse range of physical activity and exercise task options. The purpose of this dissertation is to investigate the associations between mental fatigue, motivation, and physical activity behavior to further our understanding of the decision- processes behind choosing to engage or not engage in physical activity.
Study 1 examined the effects of mental fatigue on the decision to engage in an acute bout of moderate-to-vigorous intensity physical activity or a competing sedentary alternative using a mixed-methods study design. Results showed a sequential mediation effect of mental fatigue on choice through subjective perceptions of effort, benefits, and costs. Results of qualitative analyses highlight individual-level consequences of completing cognitively demanding and non-demanding tasks on physical activity decision-making. Findings are consistent with previous research and demonstrate subjective perceptions of engaging in physical activity account for acute choice.
Study 2 investigated the effects of intensity and duration on people’s subjective valuations of physical activity tasks using an effort discounting paradigm and the potential moderating effect of mental fatigue on subjective valuations of physical activity. Results showed a reduced willingness to engage in physical activities of higher intensities and longer durations. Further, there was partial evidence suggesting a reduced willingness to engage in vigorous-intensity physical activity with higher levels of mental fatigue. Findings provide novel insight towards factors influencing people’s motivation for engaging in physical activity with some evidence that mental fatigue affects people’s motivation to exert physical effort.
Study 3 examined the association between mental fatigue, subjective evaluations of perceived benefits and costs, and moderate-to-vigorous intensity physical activity using ecological momentary assessment and accelerometry. Results demonstrate significant associations between all study variables. Although a multilevel mediation model was not significant, evidence supports a partial mediation effect attributable to benefit vs. cost valuation on the relation between mental fatigue and physical activity. Results provide insight into real-time predictors of motivation and physical activity, highlighting the complex relationships between psychological variables and behavior in people’s everyday decision making.DissertationDoctor of Philosophy (PhD)Mental fatigue has been shown to impair subsequent physical performance, however, the effect of mental fatigue on the decision to engage or not engage in physical activity has received limited attention. This thesis addresses several gaps in the literature by examining potential mediators of the mental fatigue – physical activity decision- making relation, using qualitative methods to understand factors affecting people’s choices, and applying methods with strong ecological validity. Findings show perceived effort and benefit vs. cost valuations associated with engaging in physical activity predict the choice to engage in PA. Further, mental fatigue increases perceptions of effort and decreases benefit vs. cost valuations. Collectively, results from this dissertation align with and extend theoretical frameworks of behavioral economics, motivation, and effort-based decision-making
Effects of Cognitive Control Exertion on Feeling States and Performance of a Graded Exercise Test
Get PDFExerting cognitive self-control leads to subsequent decrements in muscular and cardiovascular endurance performance. According to the Process Model of self-control, affective feeling states may account for later self-control impairments. Affective feeling states are sensitive to exercise and show a pronounced negative shift in valence at the ventilatory threshold (VT). The purpose of this study was to investigate feeling states in response to a challenging cognitive control task (stop-signal task; SST) followed by a graded exercise task to exhaustion (GXT). Recreationally active participants (N = 20; Mage = 20.25) completed two testing sessions separated by one week. Sessions were counterbalanced, with either a control (SST-C) or experimental (SST-E) task performed prior to each GXT. Feeling states were measured using the Feeling Scale (FS) and Felt Arousal Scale (FAS) throughout both tasks. Time to exhaustion on the GXT was significantly shorter following the SST-E than the SST-C (p < .05; d = .49). Repeated measures MANOVA showed similar within-task changes in FS in both conditions, but no significant differences between conditions during the SST tasks; however, FAS scores were significantly higher during the SST-E compared to the SST-C (p < .01). There were no significant differences in feeling states prior to, or upon completion of, the GXTs. However, FS was significantly less positive at iso-time corresponding to predicted VT in the SST-E condition (p < .05). Results show feeling states during exercise are altered by prior cognitive control exertion. Decreases in positive valence in concert with increased activation may prime a negative shift in affect as exercise becomes more strenuous and thereby reduce self-control (exercise tolerance), as predicted by the Process Model. Alternatively, shifts in affect may reflect responses to physiological manifestations of fatigue that carry over from cognitive to physical tasks and become salient at moderate exercise intensities.ThesisMaster of Science (MSc
EFFECTS OF MENTAL FATIGUE ON EXERCISE DECISION-MAKING
Get PDFPeople’s decisions regarding effort-based tasks such as engaging in physical activity depend on the subjective value of the activity: weighing the costs against the benefits (Chong et al., 2016). Exerting cognitive effort while performing one task negatively biases people's decisions to exert effort on subsequent cognitive tasks, suggesting a shift in their subjective valuation of the task due to mental fatigue (Kool & Botvinick, 2014). Similarly, exerting physical effort negatively biases decisions to further exert effort on a future physical task (Iodice et al., 2017a, Iodice et al., 2017b). The purpose of the present study was to investigate the effect of mental fatigue on people's decisions to engage in an acute bout of exercise and whether the effect of mental fatigue on decision-making was mediated by a benefit-cost analysis. Among those who decided to exercise, the study also aimed to investigate the relationship between mental fatigue and exercise behaviours during a self-selected, self-paced, bout of exercise. Recreationally active participants (N = 55, Mage = 19.04 ± 1.04 years) completed either a 10-minute, high cognitive demand (Stroop) task or low cognitive demand (documentary viewing) task to manipulate levels of mental fatigue. Participants then made a choice between engaging in a 20-minute self-paced moderate-to-vigorous intensity exercise task or a 20-minute non-exercise task. Prior to choosing, participants rated their mental fatigue and their perceived benefits and costs of the exercise task. The cognitive task had a strong effect on mental fatigue (p < .001, Cohen's d = 1.40). The mediation analysis showed no direct effect of mental fatigue on choice; however, there was a significant indirect effect indicating the benefit-cost score mediated the effect of mental fatigue on choice (95% C.I. = -.02 to -.0004). Higher levels of mental fatigue were associated with a lower benefit-cost score (r = -.33, p = .01) which, in turn, was associated with a decreased likelihood of choosing the exercise task (r = .31, p = .02). For those who chose to engage in the exercise task (N = 28), higher levels of mental fatigue were associated with higher ratings of perceived exertion (r = .38, p = .05). Findings provide insight into the effects of mental fatigue on people's exercise behaviours, illustrating a rational decision-making process that is dependent upon the subjective evaluation of the costs and benefits of engaging in physical activity or sedentary alternatives.ThesisMaster of Science (MSc
Effects of Self-Control Exertion on Mental Fatigue and Perceived Exertion during Whole-Body Exercise
Get PDFSelf-control exertion leads to performance decrements during tasks demanding of muscular and cardiovascular systems (Bray et al., 2008; Marcora et al., 2009). Several reviews have also implicated self-control depletion with the psychobiological state of fatigue (Hagger et al., 2010; Van Cutsem et al., 2017). In this state, individuals have also been noted to report higher levels of perceived exertion when exercising at vigorous intensities (MacMahon et al., 2014; Marcora et al., 2009; Wagstaff et al., 2014). The purpose of this study was to investigate physical performance and ratings of perceived exertion during a self-paced maximum distance cycling trial (MDT) following a short bout of mentally-fatiguing cognitive activity (thought-suppression). Recreationally active participants (N = 16, Mage = 20.94) completed one familiarization session and two testing sessions. All visits were separated by ≥ 72-hours. Control and experimental trials were counterbalanced, with either a 6-minute bout of thought-logging (control) or a 6-minute bout of thought-suppression (experimental) being performed prior to each respective MDT. Ratings of perceived exertion (RPE) were solicited from participants across three sensory domains relevant to MDT task performance (Leg-muscle, Respiration, Mental). Thought-suppression was perceived to be significantly more demanding than the control task, which resulted in significantly higher ratings of mental fatigue (p = 0.04, 2 = 0.26). Distance travelled on the MDT was not significantly different following thought suppression, relative to control trials (p = 0.84, 2 = 0.00). Similarly, a repeated-measures ANOVA showed no differences in HR between conditions (p = 0.95, 2 = 0.00). Despite these similarities, ratings of perceived leg-muscle exertion (RPE-L) were significantly higher during the MDT following thought-suppression (p = 0.05, 2 = 0.24). RPE-R (respiration) and RPE-M (mental) ratings also trended towards higher scores following the experimental manipulation, although they did not differ significantly. RPE-L was perceived to be significantly higher than both RPE-R and RPE-M in both conditions on the MDT (ps < 0.05). RPE-M was rated significantly lower than RPE-L and RPE-R during MDTs in both conditions (ps < 0.05). Results indicate that performing a demanding self-control exertion task for a short duration leads to increased feelings of mental fatigue. The observed levels of fatigue were also associated with higher than normal ratings of perceived exertion during cycling tasks of equal demands and performance.ThesisMaster of Science (MSc)Any thought, emotion or behaviour that an individual modifies in order to better suit their goals occurs as a result of self-control exertion. Research indicates that just like the exertion of muscular strength, exerting self-control impacts subsequent attempts to do so. Using a mentally-demanding task, we induced states of self-control depletion which left individuals feeling mentally-fatigued. As a result of this state, participants needed to exert themselves harder in order to complete a task that was perceived less demanding, when non-fatigued
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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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