Longer breastfeeding durations may enhance cognition and accelerate motor development; motor development, and in particular, crawling, may lead to dramatic changes in cognition. Based on these empirical relations, the hypothesis that crawling mediates breastfeeding duration and cognitive outcome was tested. Specifically, it was hypothesized that longer breastfeeding durations would significantly predict both earlier crawling and higher cognitive scores at 2 years of age, that earlier crawling would also predict higher cognitive scores, and that earlier crawling would account for part of the relationship between longer breastfeeding durations and higher cognitive scores. A sample of 44 full term infants from Winnipeg, Manitoba was followed longitudinally between birth and 2 years of age. Data on breastfeeding duration and crawling were collected through daily parent checklists, with supplemental breastfeeding information obtained via questionnaires. Near the toddlers’ 2nd birthdays, cognitive abilities were assessed with the MacArthur Communicative Development Inventory: Words and Sentences (Fenson et al., 1993) and the Parent Report of Children’s Abilities (Saudino et al., 1998). All 3 key variables were measured on continuous scales, and a mediational analysis based on Baron and Kenny’s (1986) classic approach of 3 regressions was used. Several covariates were considered for inclusion in the regressions, but none reached significance in preliminary tests and thus, were not included. In the first 2 regression analyses, exclusive and partial breastfeeding durations significantly predicted neither cognitive scores (p = .59) nor age of crawling attainment (p = .41). The 3rd regression analysis showed a significant, small-to-medium effect size for earlier crawling attainment predicting higher cognitive scores (p < .05, adjusted R2 = .09). However, crawling onset had no effect on the breastfeeding-cognition link. The overall test of the mediation was inconclusive, due to low power. The significant finding between age of crawling onset and cognitive outcomes at 2 years of age may be due to earlier crawling altering the course of development, to reverse causation whereby more cognitively advanced infants are motivated to crawl sooner, or to a 3rd variable affecting both crawling and cognition. Future research should continue to explore motor and cognitive connections in infant development. / May 2005

In this report from the Childhood Cancer Survivor Study (CCSS), we described marriage and divorce rates in survivors of childhood cancer, as compared to a sibling control group and the general U.S. population. We also sought to identify patient and treatment characteristics that were associated with survivor marital status. This study included 8,930 five-year survivors of childhood malignancy and 2,855 sibling controls participating in the CCSS. Data on marital status, sociodemographic factors, and current health status were obtained from questionnaires; detailed disease and treatment histories were available from medical records. Marital status of the U.S. population was obtained from the 2002 Current Population Survey of the U.S. Census. We found that survivors were more likely to have never married than both sibling (odds ratio [OR] = 1.79; 95 % CI = 1.65-1.94; p < 0.0001) and population controls (OR = 2.29; 95 % CI = 2.19-2.38; p < 0.0001), with persistence of trends across age and gender strata. Once married, survivors divorced at rates equivalent to controls. In adjusted analysis, we found that several survivor characteristics predicted never-married status, including treatment involving cranial radiation (OR = 2.41; p < 0.0001), CNS tumor diagnosis (OR = 2.05; p < 0.0001), history of growth hormone deficiency (OR = 2.02; p < 0.0001), and unemployment secondary to disability (OR = 1.78; p = 0.0001). Survivor characteristics predictive of divorce included unemployment (OR = 1.91; p < 0.0001, for unemployed or disabled), lower educational achievement (OR = 1.74; p < 0.0001, for non-college graduates), and psychological distress (OR = 1.60; p < 0.0001). This study confirms prior reports of lower marriage rates in survivors of childhood cancer, providing further evidence that this population struggles with psychosocial adjustment to adult life.

Thesis (M. Div.)--Emmanuel School of Religion, Johnson City, Tennessee, 2000. / Vita. Includes bibliographical references (leaves 48-51).

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Transitive inference refers to the ability to use knowledge of pre-existing relationships to infer relationships between entities that have not been directly compared. This form of logical inference is an important skill for many social species, and has been thought to arise in an immature form in humans between the ages of four and six years. The experimental methods used to test this ability in humans often require some verbal skill, gross or fine motor coordination, a memory capable of containing numerous relationships, and often a great deal of time and repetition in testing. These methods of testing may have been too demanding on other physical and cognitive abilities to be successfully completed by children under four years of age, regardless of their ability to make transitive inferences. The present study used methods sensitive to infant cognition to test the current theory that the ability to make transitive inferences does not develop until the age of four. Nine-month-old infants were tested in three separate experiments using a visual habituation paradigm similar to that used by Woodward (1998) and through investigation of infants’ own imitative actions. Experiment 1 verified that infants can track the goals of others in a habituation paradigm when the goal object changes position throughout habituation trials, both through looking time measures and imitative action. Experiment 2 used an extension of this paradigm to examine the ability to make transitive inferences across a three item chain, serially ordered by the actor’s object preference, and no evidence of transitive inference was observed. Experiment 3 tested infants’ ability to habituate to and recall multiple goals using context as a cue to actor choice. Infants were able to consistently track only one of the pairings, suggesting that avoidance, in addition to selection, may play a role in infant performance in the visual habituation paradigm. / Thesis (Master, Neuroscience Studies) -- Queen's University, 2012-08-14 09:10:37.385

Presented in this thesis are the results of a 23-month field study (April 1991 - February 1993) which focused on infant development in a free-ranging baboon troop (Papio cynocephalus ursinus) inhabiting the Cathedral Peak Reserve in the Drakensberg Mountains, Natal Province (South Africa). The troop selected for study was, in demographic composition, representative of the greater Drakensberg baboon population. During the course of the study, five infants were born into the troop. At the end of the data collection period, the infants ranged in age from II-months to 17 -months old. The data presented are extracted primarily from 2678 half-hourly scan samples, representing approximately 1340 hours of observation. Data presented in this study indicate that baboon births in the Drakensberg are seasonally timed such that mothers are afforded some measure of relief from the energetic costs associated with intense infant dependency, particularly during the first few months postpartum. However, the timing of births is not optimal in terms of the development of infant nutritional independence. This has implications for the interbirth interval (38.4 months) which, for the Drakensberg females, is substantially longer than that for comparative studies, while the rate of infant survivorship through to 12-months (95%) is considerably higher than for other baboon populations. The development of independent feeding for the Drakensberg infants is, when compared with infants from other studies, considerably slower. The delayed transition to independent feeding which was observed is explained with reference to seasonally variable ecological conditions in the Drakensberg which necessarily resulted in infants remaining nutritionally dependent on mothers for a longer time than would normally be expected. The relationship between dependent and independent feeding, as alternate infant strategies, is considered within the context of weaning and its role in the iv promotion of independence. A model which purports to delineate the weaning period with reference to the rate of decline in various measures of maternal investment is applied to the data for this study, as well as for comparative studies. No clear consistency is evident in the rate of decline across the various measures for the present study. The trajectories of infant behavioural development toward the adult model of independent activity are described and considered. With the exception of nutritional independence, all other trajectories of infant behaviour followed similar developmental patterns to infants in comparative studies. Thus the appearance of particular behaviours, and the age at which transitions to independence were made, confirmed a general baboon pattern. The implications and consequences of delayed feeding independence for changes in behavioural development are considered within the context of general activity budgets. Data are also presented which examine the contexts within which adult males interact with infants. These data are considered in relation to the possible functional purposes served by male interaction with infants, as well as in terms of the effect male interaction with infants has on inter-male interaction. The data indicate individual male variability in both the extent and contexts of interaction with infants. / Thesis (Ph.D.)-University of Natal, Durban, 1994.

Both behavioral and neurophysiological data indicate that many factors contribute to how infants tune to their native language(s) in early infancy. However, substantial debate remains regarding the neural mechanisms that underlie this tuning process. This study was designed to determine whether the behavioral changes in infants' processing of native and non-native speech during the second half of the first year correspond to qualitative neural processing changes that can be measured using near-infrared spectroscopy (NIRS). Specifically, we used NIRS to examine changes in hemodynamic activity in monolingually-exposed infants between the ages of 3 and 14 months while they were exposed to native (English) and non-native (Spanish) speech. In all infants, measurements were taken from the bilateral temporal regions of the cerebral cortex. Three age groups were tested: pre-tuned infants, who should show no sensitivity to phonological differences between the native and non-native speech samples (3-to-6-month-olds), actively tuning infants, who should be beginning to differentiate between the phonology of the native and non-native speech samples (7-to-10-month-olds), and tuned infants, who should readily distinguish between the phonologies of the native and non-native speech samples (11-to-14-month-olds). Results demonstrated significant differences in hemodynamic activity during the processing of native speech compared to non-native speech in each of the three age groups, with qualitatively different patterns of hemispheric lateralization emerging in response to the two types of speech in each of the three groups. These findings point to a potential neural marker of infants' sensitivity to the phonology of their native language as it emerges with increasing age that will be useful in future research.

Longer breastfeeding durations may enhance cognition and accelerate motor development; motor development, and in particular, crawling, may lead to dramatic changes in cognition. Based on these empirical relations, the hypothesis that crawling mediates breastfeeding duration and cognitive outcome was tested. Specifically, it was hypothesized that longer breastfeeding durations would significantly predict both earlier crawling and higher cognitive scores at 2 years of age, that earlier crawling would also predict higher cognitive scores, and that earlier crawling would account for part of the relationship between longer breastfeeding durations and higher cognitive scores. A sample of 44 full term infants from Winnipeg, Manitoba was followed longitudinally between birth and 2 years of age. Data on breastfeeding duration and crawling were collected through daily parent checklists, with supplemental breastfeeding information obtained via questionnaires. Near the toddlers’ 2nd birthdays, cognitive abilities were assessed with the MacArthur Communicative Development Inventory: Words and Sentences (Fenson et al., 1993) and the Parent Report of Children’s Abilities (Saudino et al., 1998). All 3 key variables were measured on continuous scales, and a mediational analysis based on Baron and Kenny’s (1986) classic approach of 3 regressions was used. Several covariates were considered for inclusion in the regressions, but none reached significance in preliminary tests and thus, were not included. In the first 2 regression analyses, exclusive and partial breastfeeding durations significantly predicted neither cognitive scores (p = .59) nor age of crawling attainment (p = .41). The 3rd regression analysis showed a significant, small-to-medium effect size for earlier crawling attainment predicting higher cognitive scores (p < .05, adjusted R2 = .09). However, crawling onset had no effect on the breastfeeding-cognition link. The overall test of the mediation was inconclusive, due to low power. The significant finding between age of crawling onset and cognitive outcomes at 2 years of age may be due to earlier crawling altering the course of development, to reverse causation whereby more cognitively advanced infants are motivated to crawl sooner, or to a 3rd variable affecting both crawling and cognition. Future research should continue to explore motor and cognitive connections in infant development.

Longer breastfeeding durations may enhance cognition and accelerate motor development; motor development, and in particular, crawling, may lead to dramatic changes in cognition. Based on these empirical relations, the hypothesis that crawling mediates breastfeeding duration and cognitive outcome was tested. Specifically, it was hypothesized that longer breastfeeding durations would significantly predict both earlier crawling and higher cognitive scores at 2 years of age, that earlier crawling would also predict higher cognitive scores, and that earlier crawling would account for part of the relationship between longer breastfeeding durations and higher cognitive scores. A sample of 44 full term infants from Winnipeg, Manitoba was followed longitudinally between birth and 2 years of age. Data on breastfeeding duration and crawling were collected through daily parent checklists, with supplemental breastfeeding information obtained via questionnaires. Near the toddlers’ 2nd birthdays, cognitive abilities were assessed with the MacArthur Communicative Development Inventory: Words and Sentences (Fenson et al., 1993) and the Parent Report of Children’s Abilities (Saudino et al., 1998). All 3 key variables were measured on continuous scales, and a mediational analysis based on Baron and Kenny’s (1986) classic approach of 3 regressions was used. Several covariates were considered for inclusion in the regressions, but none reached significance in preliminary tests and thus, were not included. In the first 2 regression analyses, exclusive and partial breastfeeding durations significantly predicted neither cognitive scores (p = .59) nor age of crawling attainment (p = .41). The 3rd regression analysis showed a significant, small-to-medium effect size for earlier crawling attainment predicting higher cognitive scores (p < .05, adjusted R2 = .09). However, crawling onset had no effect on the breastfeeding-cognition link. The overall test of the mediation was inconclusive, due to low power. The significant finding between age of crawling onset and cognitive outcomes at 2 years of age may be due to earlier crawling altering the course of development, to reverse causation whereby more cognitively advanced infants are motivated to crawl sooner, or to a 3rd variable affecting both crawling and cognition. Future research should continue to explore motor and cognitive connections in infant development.

Thesis (M. Div.)--Emmanuel School of Religion, Johnson City, Tennessee, 2000. / Vita. Includes bibliographical references (leaves 48-51).