1,720,976 research outputs found
Acute Maternal Stress Disrupts Infant Regulation of the Autonomic Nervous System and Behavior: A CASP Study
Get PDFExposure to maternal stress is assumed to influence infant health and development across the lifespan. The autonomic nervous system (ANS) is especially sensitive to the effects of the early caregiving environment and linked to predictors of later mental health. Understanding how exposure to maternal stress adversely affects the developing ANS could inform prevention. However, there is no agreed upon definition of maternal stress making its study difficult. Here we use the Caretaker Acute Stress Paradigm (CASP) to study the effects of maternal stress in an experimentally controlled laboratory setting. The CASP has 5 episodes, a natural play, followed by a caretaker stressor (or control) condition, another play, a classic still face episode, followed by another play. A total of 104 4-months-old infants and their mothers were randomly assigned to either the caretaker-stress or caretaker-control condition. Changes in behavior, heart rate (HR), and respiratory sinus arrhythmia (RSA) before and after the introduction of the stressor (or control condition) were recorded and compared. Infants in the maternal stress condition showed significantly more behavioral distress [X2 = (1, N = 104) = 4.662, p = 0.031]. Moreover, infants whose mothers were in the stress condition showed an significant increase in heart rate after the caretaker condition [F(1, 102) = 9.81, p = 0.002]. Finally we observed a trend to faster RSA recovery in infants of the control condition [F(1, 75) = 3.539, p = 0.064]. Results indicate that exposure to acute maternal stress affects infant regulation of the autonomic nervous system and behavior
Social stress regulation in 4-month-old infants: Contribution of maternal social engagement and infants' 5-HTTLPR genotype
No full textBackground: Maternal behavior and infant 5-HTTLPR polymorphism have been linked to infants' social stress reactivity and recovery at different ages. Nonetheless, Gene × Environment (G × E) studies focusing on early infancy are rare and have led to mixed results.
Aim: To investigate the contribution of maternal social engagement and infants' 5-HTTLPR polymorphism in
predicting infants' negative emotionality in response to a social stressor, namely maternal unresponsiveness.
Study design: Cross-sectional, G × E study.
Subjects: 73 4-month-old infants and their mothers took part to the Face-to-Face Still-Face (FFSF) procedure.
Outcomemeasures: A micro-analytical coding of negative emotionality was adopted to measure infants' reactivity to social stress (Still-Face episode) and infants' recovery after social stress (Reunion episode). Maternal contribution was measured as maternal social engagement during the Play episode. Infantswere genotyped as S-carriers or L-homozygotes.
Results: The interplay between maternal social engagement and infants' genotype was found to be predictive of infants' negative emotionality during both Still-Face and Reunion episodes of the FFSF paradigm. The interaction highlighted that maternal social engagement predicted minor negative emotionality during Still-Face and Reunion episodes for S-carrier infants, but not for L-homozygotes.
Conclusions: Findings extend previous results on adults and children, highlighting that maternal behavior
might be a protective factor for stress reactivity and regulation, especially for S-carrier infants who are at risk
for heightened stress susceptibility
Vagal tone as a biomarker of long-term memory for a stressful social event at 4 months
No full textThis study investigates infants' memory for social stress after a 15-day retention interval using behavior and respiratory sinus arrhythmia (RSA). Experimental group infants were exposed to face-to-face still-face paradigm (FFSF) two times; the first time at 4 months and after a 2-week interval. Control group infants were exposed to FFSF only once at 4 months plus 2 weeks. Infants were categorized as suppressors or non-suppressors based on the direction of RSA change at first FFSF exposure. No behavioral differences were found among groups and exposure conditions. In the experimental group suppressors changed and showed no suppression when re-exposed 2 weeks later to FFSF. Non-suppressors showed no change in RSA from the first to the second exposure to FFSF. Control infants showed similar RSA changes to experimental infants at their first exposure. Findings indicate that 4-month-old infants have memory for social stress related to individual differences in autonomic reactivity. © 2014 Wiley Periodicals, Inc
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
Risk and Protective Factors Associated with Early Adversity and Development: Evidence from Human and Animal Research
No full textThis eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contac
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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