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71.
We examine the hypothesis that the efficiency of executive control processes is less stable over time in older than younger adults. An age-related decrease in the efficiency of executive control should result in an increase in performance variability in task conditions requiring the recruitment of executive control processes and not in task conditions requiring minimal involvement of executive control. Performance variability was similar for younger and older adults in task conditions requiring minimal executive control and greater for older than younger adults in task conditions requiring executive control. These and other data are consistent with the proposal that aging is associated with a decrease in the stability of executive control over time. 相似文献
72.
We review recent discoveries that implicate oxytocin in the intergenerational transmission of similar levels of maternal behavior and acute stress responses in female rats. First, ICV-infused oxytocin antagonist decreased the display by nursing dams of pup-licking (PL) and arched-back nursing (ABN), but not other components of maternal behavior, and increased maternal self-grooming suggesting that oxytocin may shift the balance of oral grooming by dams away from themselves and toward pups. Second, oxytocin receptor concentrations in areas of the adult brain where oxytocin stimulates maternal behavior or diminishes anxiety and adrenal axis responses to acute stress were positively related to PL-ABN received during infancy. Third, oxytocin and oxytocin antagonist treatments of pups on postnatal days 2-10, respectively increased and decreased PL by the treated rats when adult and themselves nursing dams. This indicates that oxytocin activity in female pups, which may be regulated by PL-ABN received from their mothers, influences their adult levels of PL. These three lines of evidence suggest that oxytocin selectively enhances PL-ABN by rat dams, which then increases oxytocin activity in female pups and, thereby, facilitates their expression of central oxytocin receptors (and perhaps other aspects of central oxytocin systems) and, consequently, their adult PL-ABN frequencies and acute stress responses. 相似文献
73.
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75.
The purpose of this study was to identify factors associated with early onset of sexual intercourse. Within an ecological system's conceptual framework, familial factors associated with early onset of sexual activity were identified in a sample of 425 adolescents from San Juan metro area schools. Measures included questions about sexual activity, sexual permissiveness, and such familial variables as: discipline, parental supervision, and parental support. Significant relationships were observed between early onset of sexual intercourse and parental supervision, discipline, parental support, and parents' marital status. Results suggest the key role of parents and family in prevention of HIV-risk behaviors among adolescents in terms of delaying sexual onset. Overall, the study described youths who postponed sexual activity as having greater support, supervision, and parental involvement. 相似文献
76.
Roncesvalles MN Schmitz C Zedka M Assaiante C Woollacott M 《Journal of motor behavior》2005,37(5):404-416
The authors investigated the emergence of independent control of body segments in bimanual tasks involving either voluntary or involuntary trunk motion by tracking the transition from an ego- to an exocentric mode of postural control during childhood (i.e., from body-referenced orientation to externally referenced action). A paradigm combining a seated manual task and various trunk manipulations described the coordination strategies used by 24 children at different ages (2 to 9 years) and by adults. The following questions were asked: (a) When do children begin to dissociate upper limb movements from those of the trunk? (b) What segmental strategies are exhibited by each age group (2-3, 4-6, and 7-9 years, and adults)? Kinematic analyses revealed that younger children (2-6 years) used either the trunk or the support surface as reference to orient the limbs. Older children (7-9 years) began to use a gravitational reference frame similar to that of adults; they uncoupled upper limb motion from the trunk in either voluntary or imposed conditions. Young children patterned the forearm trajectory after the initiating segment (support surface or the trunk), thus reducing the degrees of freedom during the dual task. Echoing previous reports, 7-9 years of age appears to be a critical period in which children master postural control and develop an internal representation of body scheme. 相似文献
77.
Amador-Campos JA Forns-Santacana M Martorell-Balanzó B Guàrdia-Olmos J Peró-Cebollero M 《Psychological reports》2005,97(3):847-860
Confirmatory factor analysis examined the factor structure of DSM IV Attention Deficit Hyperactivity Disorder symptoms and analyzed the differences in informants' ratings of ADHD symptoms by children's age and sex. A sample of 1,018 Spanish school children, 574 girls and 444 boys, ages 4 to 12 years, was rated by teachers and parents. Confirmatory factor analysis showed a similar fit for the three-factor model of Inattention, Hyperactivity, and Impulsivity (teachers: CFI = .976, RMR = .041, % of total variance = 83.2; parents: CFI = .969, RMR = .037, % of total variance = 82.7) and for the two-factor model of Inattention and Hyperactivity Impulsivity (teachers: CFI = .958, RMR = .044, % of total variance = 79.3; parents: CFI = .961, RMR = .038, % of total variance, 79.9). The two-factor model was selected as a parsi monious representation of the teachers' and parents' ratings of ADHD symptoms. Analyses of variance indicated significant differences in teachers' and parents' mean ratings across sex and school grades of children. 相似文献
78.
Truchan-Tataryn M 《The Journal of medical humanities》2005,26(2-3):159-172
William Faulkner's The Sound and the Fury has become a classic in literary history. Since its publication in 1929, it has sustained critical interest worldwide. Over time, analyses of this work have reflected shifting cultural perspectives of the inscribed human dynamics such as gender, race and sexuality. This paper contends that a similar critical development cannot be detected around the reception of the character of the "idiot," Benjy. Faulknerian scholarship, regardless of its place in time or trend, persists in conflating the dehumanized images of Benjy with the lived experience of disability, thus perpetuating oppressive disability prejudice and limiting the richness of the character's metaphoric potential. Acknowledging this critical lacuna, historicizing and theorizing Benjy's character from a disability perspective could lead to a deeper understanding of human experience. 相似文献
79.
This review identified 1275 studies examining cognitive deficits in people with schizophrenia, published between 1990 and
2003. Data from 113 studies (4365 patients and 3429 controls) were combined in a meta-analysis carried out on the five cognitive
domains of IQ, memory, language, executive function, and attention. Studies were excluded where they lacked a suitable control
group or failed to present complete information. In all five cognitive domains, analysis indicated a consistent trend for
patients to perform more poorly than healthy controls, with significant heterogeneity across studies. Sources of heterogeneity
were analyzed and a need to ensure more appropriate composition of patient and control groups and to adopt a more refined
and methodologically correct, hypothesis-driven approach was identified. 相似文献
80.
The transmission of tool use is a rare event in monkeys. Such an event arose in a group of semi-free-ranging Tonkean macaques (Macaca tonkeana) in which leaning a pole against the parks fence (branch leaning) appeared and spread to several males. This prompted us to test individual and social learning of this behavior in seven young males. In the first experiment, three males learned individually to obtain a food reward using a wooden pole as a climbing tool. They began using the pole to retrieve the reward only when they could alternatively experience acting on the object and reaching the target. In a second experiment, we first tested whether four other subjects could learn branch leaning after having observed a group-mate performing the task. Despite repeated opportunities to observe the demonstrator, they did not learn to use the pole as a tool. Hence we exposed the latter subjects to individual learning trials and they succeeded in the task. Tool use was not transmitted in the experimental situation, which contrasts with observations in the park. We can conclude that the subjects were not able to recognize the target as such. It is possible that they recognized it and learned the task individually when we alternated the opportunity to act upon the object and to reach the reward. This suggests that these macaques could then have associated the action they exercised upon the pole and the use of the pole as a means to reach the reward. 相似文献