Purpose： This study aimed to investigate the construct of external visual imagery （EVI） vs. internal visual imagery （IV/） by comparing the athletes＇ imagery ability with their levels of skill and types of sports...Purpose： This study aimed to investigate the construct of external visual imagery （EVI） vs. internal visual imagery （IV/） by comparing the athletes＇ imagery ability with their levels of skill and types of sports. Methods： Seventy-two young athletes in open （n = 45） or closed （n = 27） sports and with different skill levels completed 2 custom-designed tasks. The EVI task involved the subject generating and visualizing the rotated images of different body parts, whereas the IVI task involved the subject visualizing himself or herself performing specific movements. Results： The significant Skill-Level x Sport Type interactions for the EVI task revealed that participants who specialized in open sports and had higher skill-levels had a higher accuracy rate as compared to the other subgroups. For the IVI task, the differences between the groups were less clear： those with higher skill-levels or open sports had a higher accuracy rate than those with lower skill-levels or closed sports. Conclusion： EVI involves the visualization of others and the environment, and would be relevant to higher skill-level athletes who engage in open sports. IVI, in contrast, tends to be more self-oriented and would be relevant for utilization by higher skill-level athletes regardless of sport type.展开更多
As complex traits evolve, each component of the trait may be under different selection pressures and could respond independently to distinct evolutionary forces. We used comparative methods to examine patterns of evol...As complex traits evolve, each component of the trait may be under different selection pressures and could respond independently to distinct evolutionary forces. We used comparative methods to examine patterns of evolution in multiple components of a complex courtship signal in darters, specifically addressing the question of how nuptial coloration evolves across different areas of the body. Using spectral reflectance, we defined 4 broad color classes present on the body and fins of 17 species of freshwater fishes （genus Etheostoma） and quantified differences in hue within each color class. Ancestral state reconstruction suggests that most color traits were expressed in the most recent common ancestor of sampled species and that differences among species are mostly due to losses in coloration. The evolutionary lability of coloration varied across body regions; we found sig- nificant phylogenetic signal for orange color on the body but not for most colors on fins. Finally, patterns of color evolution and hue Of the colors were correlated among the two dorsal fins and between the anterior dorsal and anal fins, but not between any of the fins and the body. The observed patterns support the hypothesis that different components of complex signals may be subject to distinct evolutionary pressures, and suggests that the combination of behavioral displays and morphology in communication may have a strong influence on patterns of signal evolution .展开更多
基金supported by the Dr.and Mrs.Sui Kau Chan donation grant for sports training and rehabilitation held by Chetwyn C.H.Chan and Amy S.N.Fuand by an internal grant awarded to Chetwyn C.H.Chan by The Hong Kong Polytechnic University
文摘Purpose： This study aimed to investigate the construct of external visual imagery （EVI） vs. internal visual imagery （IV/） by comparing the athletes＇ imagery ability with their levels of skill and types of sports. Methods： Seventy-two young athletes in open （n = 45） or closed （n = 27） sports and with different skill levels completed 2 custom-designed tasks. The EVI task involved the subject generating and visualizing the rotated images of different body parts, whereas the IVI task involved the subject visualizing himself or herself performing specific movements. Results： The significant Skill-Level x Sport Type interactions for the EVI task revealed that participants who specialized in open sports and had higher skill-levels had a higher accuracy rate as compared to the other subgroups. For the IVI task, the differences between the groups were less clear： those with higher skill-levels or open sports had a higher accuracy rate than those with lower skill-levels or closed sports. Conclusion： EVI involves the visualization of others and the environment, and would be relevant to higher skill-level athletes who engage in open sports. IVI, in contrast, tends to be more self-oriented and would be relevant for utilization by higher skill-level athletes regardless of sport type.
基金Acknowledgements We thank Michael Martin, Tory Williams, and Alex Nahm for assistance in collecting fishes and the Mendelson lab for assistance in fish maintenance. We thank Chioma Ihekweazu for assistance with spectral analysis. We also thank Karen Carleton for use of the software to calculate spectral location. Tom Cronin, Kevin Omland, Megan Porter, Kate Feller, Nick Friedman and Brian Dalton provided helpful discussions throughout the course of this work. We thank two anonymous reviewers and the editor for their helpful comments on previous versions of this manuscript. We especially thank Eileen Hebets for the invitation to submit to this special issue. This work was funded through a National Science Foundation grant to TCM （#DEB 0718987）. Additional support for this work came from the NSF, NCEAS and NESCENT funded ＂Comparative Phylogenetics in R＂ workshop attended by JMG.
文摘As complex traits evolve, each component of the trait may be under different selection pressures and could respond independently to distinct evolutionary forces. We used comparative methods to examine patterns of evolution in multiple components of a complex courtship signal in darters, specifically addressing the question of how nuptial coloration evolves across different areas of the body. Using spectral reflectance, we defined 4 broad color classes present on the body and fins of 17 species of freshwater fishes （genus Etheostoma） and quantified differences in hue within each color class. Ancestral state reconstruction suggests that most color traits were expressed in the most recent common ancestor of sampled species and that differences among species are mostly due to losses in coloration. The evolutionary lability of coloration varied across body regions; we found sig- nificant phylogenetic signal for orange color on the body but not for most colors on fins. Finally, patterns of color evolution and hue Of the colors were correlated among the two dorsal fins and between the anterior dorsal and anal fins, but not between any of the fins and the body. The observed patterns support the hypothesis that different components of complex signals may be subject to distinct evolutionary pressures, and suggests that the combination of behavioral displays and morphology in communication may have a strong influence on patterns of signal evolution .
