Infants' perception of object trajectories     

Johnson SP  Bremner JG  Slater A  Mason U  Foster K  Cheshire A 《Child development》2003,74(1):94-108

Filling in the gaps in what humans see is a fundamental perceptual skill, but little is known about the developmental origins of occlusion perception. Three experiments were conducted with infants between 2 and 6 months of age to investigate perception of the continuity of an object trajectory that was briefly occluded. The pattern of results across experiments provided little evidence of veridical responses to trajectory occlusion in the youngest infants, but by 6 months, perceptual completion was more robust. Four-month-olds' responses indicated that they perceived continuity under a short duration of occlusion, but when the object was out of sight for a longer interval, they appeared to perceive the trajectory as discontinuous. These results suggest that perceptual completion of a simple object trajectory (and, by logical necessity, veridical object perception) is not functional at birth but emerges across the first several months after onset of visual experience.  相似文献   

Temperament,tympanum, and temperature: four provisional studies of the biobehavioral correlates of tympanic membrane temperature asymmetries     

Boyce WT  Essex MJ  Alkon A  Smider NA  Pickrell T  Kagan J 《Child development》2002,73(3):718-733

Previous research in both humans and nonhuman primates suggests that subtle asymmetries in tympanic membrane (TM) temperatures may be related to aspects of cognition and socioaffective behavior. Such associations could plausibly reflect lateralities in cerebral blood flow that support side-to-side differences in regional cortical activation. Asymmetries in activation of the left and right frontal cortex, for example, are correlates of temperamental differences in child behavior and markers of risk status for affective and anxiety disorders. Tympanic membrane temperatures might thus reflect the neural asymmetries that subserve individual differences in temperament and behavior. This report merged findings from four geographically and demographically distinctive studies, which utilized identical thermometry methods to examine associations between TM temperature asymmetries and biobehavioral attributes of 4- to 8-year-old children (N = 468). The four studies produced shared patterns of associations that linked TM temperature lateralities to individual differences in behavior and socioaffective difficulties. Warmer left TMs were associated with "surgent," affectively positive behaviors, whereas warmer right TMs were related to problematic, affectively negative behaviors. Taken together, these findings suggest that asymmetries in TM temperatures could be associated with behavior problems that signal risk for developmental psychopathology.  相似文献   

Students’ conceptions of assessment: Links to outcomes     

Gavin T.L. Brown  Gerrit H.F. Hirschfeld 《Assessment in Education: Principles, Policy & Practice》2008,15(1):3-17

Students conceive of assessment in at least four major ways (i.e., assessment makes students accountable; assessment is irrelevant because it is bad or unfair; assessment improves the quality of learning; and assessment is enjoyable). A study in New Zealand of 3469 secondary school students’ conceptions of assessment used a self‐report inventory and scores from a standardised curriculum‐based assessment of reading comprehension. Four inter‐correlated conceptions based on 11 items were found with good psychometric properties. A path‐model linking the four correlated conceptions with student achievement in reading, while taking into account student ethnicity, student sex, and student year, had good psychometric properties. The conception that assessment makes students accountable loaded positively on achievement while the three other conceptions (i.e., assessment makes schools accountable, assessment is enjoyable, and assessment is ignored) had negative loadings on achievement. These findings are consistent with self‐regulation and formative assessment theories, such that students who conceive of assessment as a means of taking responsibility for their learning (i.e., assessment makes me accountable) will demonstrate increased educational outcomes.  相似文献   

Welcoming nora: a family event     

Walsh AJ  Walsh PR  Walsh JM  Walsh GT 《The Journal of perinatal education》2011,20(3):126-129

In this column, Allison and Paul Walsh share the story of the birth of Nora, their third baby and their second child to be born at home. Allison and Paul share their individual memories of labor and birth. But their story is only part of the story of Nora's birth. Nora's birth was a family event, with Allison and Paul's other children very much part of the experience. Jane and Gavin share their own memories of their baby sister's birth.  相似文献   

Collective Trolling as a Form of Organizational Resistance: Analysis of the #Justiceforbradswife Twitter Campaign     

Gavin L. Kirkwood  Holly J. Payne  Joseph P. Mazer 《Communication Studies》2019,70(3):332-351

This case study analyzed Twitter posts from the #JusticeForBradsWife campaign against the Cracker Barrel (CB) restaurant chain. Participants in the counterinstitutional movement employed diverse message strategies of humor and resistance in using social media as a site for discourse. Thematic analysis of the most influential users revealed humor strategies including: connecting to popular culture, political comic relief and using hyperbole. Participants’ resistance strategies included: making calls for action, critiquing CB products and business partners, attacking CB patrons, critiquing CB’s social media management, and offers of support from outside organizations. These strategies reflected collective trolling, where trolling behaviors created a hidden and public hybrid form of collective resistance from nontraditional stakeholders who had contradictory goals. Implications and directions for future research are discussed.  相似文献   

The effects of load on system and lower-body joint kinetics during jump squats     

Gavin L. Moir  Jared M. Gollie  Shala E. Davis  John J. Guers  Chad A. Witmer 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(4):492-506

To investigate the effects of different loads on system and lower-body kinetics during jump squats, 12 resistance-trained men performed jumps under different loading conditions: 0%, 12%, 27%, 42%, 56%, 71%, and 85% of 1-repetition maximum (1-RM). System power output was calculated as the product of the vertical component of the ground reaction force and the vertical velocity of the bar during its ascent. Joint power output was calculated during bar ascent for the hip, knee, and ankle joints, and was also summed across the joints. System power output and joint power at knee and ankle joints were maximized at 0% 1-RM (p < 0.001) and followed the linear trends (p < 0.001) caused by power output decreasing as the load increased. Power output at the hip was maximized at 42% 1-RM (p = 0.016) and followed a quadratic trend (p = 0.030). Summed joint power could be predicted from system power (p < 0.05), while system power could predict power at the knee and ankle joints under some of the loading conditions. Power at the hip could not be predicted from system power. System power during loaded jumps reflects the power at the knee and ankle, while power at the hip does not correspond to system power.  相似文献   

Measuring the impact of employee loss     

Boyce Byerly 《Performance Improvement》2012,51(5):40-47

Turnover and retention are of major concern to organizations, and require measurement that is meaningful, accurate, and thoughtful. This article describes the main concepts, key factors, and techniques necessary to accurately measure employee loss. Regrettable and nonregrettable turnover are considered, analysis techniques are presented using case studies, strategies for controlling turnover are described, and an explanation of how improved measurement of turnover and retention can help implement organizational strategy is presented.  相似文献   

R Tricks for Kids     

W. John Braun  Bethany JG White  Gavin Craig 《Teaching Statistics》2014,36(1):7-12

Real‐world phenomena simulation models, which can be used to engage middle‐school students with probability, are described. Links to R instructional material and easy‐to‐use code are provided to facilitate implementation in the classroom.  相似文献   

Comparative Evaluations of Early Intervention Alternatives: A Response to Commentaries by Guralnick and Telzrow     

Karl R. White  Glenna C. Boyce  Glendon Casto  Mark S. Innocenti  Matthew J. Taylor  Linda Goetze  Diane Behl 《Early education and development》1994,5(1):56-68

This article responds to two commentaries by Guralnick (1993) and Telzrow (1993) published in the October 1993 issue of Early Education and Development. The commentaries addressed the six longitudinal, comparative studies from the Early Intervention Research Institute's (EIRI's) investigations of the effects and costs of early intervention for children with disabilities. In this response to their thoughtful critique, we clarify details of our research design and procedures that may have been unclear. We also discuss the specificity and consistency with contemporary developmental/ecological issues raised by Guralnick We contend that the interventions investigated address important questions about age at start, intensity, and parent involvement with which today's service providers contend. We give our opinion on how the results of these studies should be interpreted, and emphasize their implications for other second-generation early intervention research.  相似文献   

Sharing Books and Learning Language: What do Latina Mothers and Their Young Children Do?     

Lisa K. Boyce  Gina A. Cook  Lori A. Roggman  Mark S. Innocenti  Vonda K. Jump  James F. Akers 《Early education and development》2004,15(4):371-386

This study examined low-income, Spanish-speaking, immigrant Latina mothers' book sharing behaviors in relation to their children's vocabulary. Participants were 47 3-year-old children and their mothers. We addressed two research questions: (a) What interactive behaviors are evident when low-income immigrant Latina mothers and their 3-year-old children look at books together? (b) For these children and their mothers, which book-sharing behaviors are related to children's expressive language? Overall, our results indicated that mothers were involved in several kinds of interactions with the books. They enhanced their children's attention to the printed text, promoted interaction or conversation with their children about what was in the books, and somewhat less often, used more complex literacy strategies. Mothers who did these things most had children with the largest vocabularies even when mothers' vocabulary was taken into account. Implications for designing interventions for similar families are discussed.  相似文献