This study investigated the effect of two different preparation methods on hitting performance in a high&ndashfidelity; baseball batting simulation. Novice and expert players participated in one of three conditions: observation (viewing a video of the goal action), visualization (hearing a script of the goal action), or a no&ndashpreparation; control group. Each participant completed three different hitting tasks: pull hit, opposite&ndashfield; hit, and sacrifice fly. Experts had more successful hits, overall, than novices. The number of successful hits was significantly higher for both the observation and visualization conditions than for the control. In most cases, performance was best in the observation condition. Experts demonstrated greater effects from the mental preparation techniques compared to novices. However, these effects were mediated by task difficulty. The difference between experts and novices, as well as the difference between the observation and visualization conditions was greater for the more difficult hitting task (opposite&ndashfield; hitting) than for the easier hitting task (sacrifice fly). These effects of mental preparation were associated with significant changes in batting kinematics (e.g., changes in point of bat/ball contact and swing direction). The results indicate that mental preparation can improve directional hitting ability in baseball with the optimal preparation methods depending on skill&ndashlevel; and task difficulty.

Life satisfaction in people with physical disabilities is on average lower than people without disabilities. This reduction in life satisfaction may be due to a reduction in domain control. This study examines how domain control predicts life satisfaction when added to a model of other salient life satisfaction predictors. Using email survey methodology, five separate scales where used on two separate populations; people with (n= 44) and without (n= 43) a physical disability to determine each groups life satisfaction. It was found that when domain control is added to the bottom-up theory of life satisfaction, the independent direct relationships of domain control, domain importance, positive affect, and negative affect are eliminated from a stepwise multiple regression equation with domain satisfaction being the only significant predictor (â = 4.38, p< .001 for people with a physical disabilities and â = 5.48, p< .001 for people without a physical disability) of life satisfaction. The study results demonstrate that life satisfaction is predicted the same way for people with and without disabilities.

Motor-respiratory coordination is the synchronization of movement and breathing during exercise. The relation between movement and breathing can be described using relative phase, a measure of the location in the movement cycle relative to the location in the breathing cycle. Stability in that relative phase relation has been identified as important for aerobic efficiency. However, performance can be overly attracted to stable relative phases, preventing the performance or learning of more complex patterns. Little research exists on relative phase dynamics in motor-respiratory coordination, although those observations underscore the importance of learning more. In contrast, there is an extensive literature on relative phase dynamics in interlimb coordination. The accuracy and stability of different relative phases, transitions between patterns, and asymmetries between components are well understood. Theoretically, motor-respiratory and interlimb coordination may share dynamical properties that operate in their different physiological substrates. An existing model of relative phase dynamics in interlimb coordination, the Haken, Kelso, Bunz model, was used to gain an understanding of relative phase dynamics in the less-researched motor-respiratory coordination. Experiments 1 and 2 were designed to examine the interaction of frequency asymmetries between movement and breathing with relative phase and frequency, respectively. In Experiment 3, relative phase stability and transitions in motor-respiratory coordination were explored. Perceptual constraints on differences in stability were investigated in Experiment 4. Across experiments, contributions relevant to questions of coordinative variability were made using a dynamical method called cross recurrence quantification analysis. Results showed much consistency with predictions from an asymmetric extension of the Haken, Kelso, Bunz model and theoretical interpretation in the interlimb coordination literature, including phase wandering, intermittency, and an interdependence of perception and action. There were, however, notable exceptions that indicated stability can decrease with more natural frequency asymmetries and the connection of cross recurrence measures to categories of variability needs further clarification. The complex relative phase dynamics displayed in this study suggest that movement and breathing are softly-assembled by functional constraints and indicate that motor-respiratory coordination is a self-organized system.

Social influences are important determinants of drug initiation in humans, particularly during adolescence and early adulthood. My dissertation tested three hypotheses: 1) conditioned and unconditioned nicotine and social rewards elicit unique patterns of neural signaling in the corticolimbic neurocircuitry when presented in combination versus individually; 2) play behavior is not necessary for expression of social reward; and 3) social context enhances nicotine self-administration. To test the first hypothesis, Fos protein was measured in response to social and nicotine reward stimuli given alone or in combination and in response to environmental cues associated with the rewards in a conditioned place preference (CPP) test. Social-conditioned environmental stimuli attenuated Fos expression in the nucleus accumbens core. A social partner elevated Fos expression in the caudate-putamen, medial and central amygdala, and both nucleus accumbens subregions. Nicotine decreased Fos expression in the cingulate cortex, caudate-putamen, and the nucleus accumbens core. Both stimuli combined elevated Fos expression in the basolateral amygdala and ventral tegmental area, suggesting possible overlap in processing both rewards in these regions. I tested the second hypothesis with an apparatus containing compartments separated by a wire mesh barrier that allowed limited physical contact with a rat or object. While 2 pairings with a partner rat (full physical contact) produced robust CPP, additional pairings were needed for CPP with a partner behind a barrier or physical contact with an object (i.e., tennis ball). The results demonstrate that physical contact with a partner rat is not necessary to establish social-reward CPP. I tested the third hypothesis with duplex operant conditioning chambers separated either by a solid or a wire mesh barrier to allow for social interaction during self-administration sessions. Nicotine (0.015 and 0.03 mg/kg, IV) and saline self-administration were assessed in male and female young-adult rats either in the social context or isolation. Initially, a social context facilitated nicotine intake at the low dose in male rats, but suppressed intake in later sessions more strongly in female rats, suggesting that social factors exert strong sex-dependent influences on self-administration. These novel findings highlight the importance of social influences on several nicotine-related behavioral paradigms and associated neurocircuitry.

The present study utilized longitudinal data from a high-risk community sample (n=254, 52.8% female, 47.2% children of alcoholics, 74% non-Hispanic Caucasian) to test questions concerning the effects of genetic risk, parental knowledge, and peer substance use on emerging adult substance use disorders (SUDs). Specifically, this study examined whether parental knowledge and peer substance use mediated the effects of parent alcohol use disorder (AUD) and genetic risk for behavioral undercontrol on SUD. The current study also examined whether genetic risk moderated effects of parental knowledge and peer substance use on risk for SUD. Finally, this study examined these questions over and above a genetic "control" which explained a large proportion of variance in the outcome, thereby providing a stricter test of environmental influences.

Analyses were performed in a path analysis framework. To test these research questions, the current study employed two polygenic risk scores. The first, a theory-based score, was formed using single-nucleotide polymorphisms (SNPs) from receptor systems implicated in the amplification of positive effects in the presence of new/exciting stimuli and/or pleasure derived from using substances. The second, an empirically-based score, was formed using a data-driven approach that explained a large amount of variance in SUDs. Together, these scores allowed the present study to test explanations for the relations among parent AUD, parental knowledge, peer substance use, and SUDs.

Results of the current study found that having parents with less knowledge or an AUD conferred greater risk for SUDs, but only for those at higher genetic risk for behavioral undercontrol. The current study replicated research findings suggesting that peer substance use mediated the effect of parental AUD on SUD. However, it adds to this literature by suggesting that some mechanism other than increased behavioral undercontrol explains relations among parental AUD, peer substance use, and emerging adult SUD. Taken together, these findings indicate that children of parents with AUDs comprise a particularly risky group, although likelihood of SUD within this group is not uniform. These findings also suggest that some of the most important environmental risk factors for SUDs exert effects that vary across level of genetic propensity.

Recent reports have indicated that there are both mental health and educational disparities between Latino youth and their European American counterparts. Specifically, Latin youth are at a heightened risk for negative mental health outcomes in comparison to their non-Latino youth (e.g., Eaton et al., 2008). Further, 16.7% of Latino adolescents dropped out of high school compared to 5.3% of European American youth over the past several decades (1960-2011; U.S. Department of Education, 2013). Mexican American (M.A. youth in particular, have the lowest educational attainment among all Latino ethnic groups in the U.S. (U.S. Census Bureau, 2010). While these mental health and educational disparities have often been attributed to discrimination experiences that Latino youth encounter, there is also consistent empirical evidence linking discrimination with these maladjustment problems. These studies confirmed that discrimination directly related to depressive symptoms (e.g., Umana-Taylor et al., 2007), externalizing behaviors (Berkel et al., 2010), self-esteem (e.g., Zeiders et al., 2013), and academic outcomes (e.g., Umana-Taylor et al., 2012). Few studies to date have examined the underlying mechanisms (i.e., moderation and mediation) that help us to better understand resiliency paths for those Latino youth that display positive adjustment outcomes despite being faced with similar discrimination encounters that their maladjusted peers face. Therefore, the following two studies examined various mechanisms in which discrimination related to adjustment to better understand potential risk and resiliency processes in hopes of informing intervention research. Paper 1 explored cultural influences on the association between discrimination, active coping, and mental health outcomes in M.A. youth. Paper 2 examined how trajectories of discrimination across 5th, 7th, and 10th grades related to cultural values, externalizing behaviors, and academic outcomes in M.A. youth. Taken together, these studies provide a culturally informed overview of adjustment processes in M.A. adolescents who face discrimination in addition to identifying critical directions for future research in efforts to gaining a more contextualized and comprehensive understanding of the dynamic processes involved in discrimination and adjustment in M.A. youth.

ABSTRACT

While the cross-cultural literature on body dissatisfaction among Mexican and Mexican-American women has continued to grow, the traditional Latino female gender role of marianismo, sociocultural factors related to ethnic culture and mainstream/American culture ideal perceived discrepancies in body size, and one’s romantic relationship have not been explored with this population in relationship to body satisfaction. The current study included 227 female participants predominantly from a large southwestern university in the United States and a large university in northern Mexico. The study examined differences in marianismo and body satisfaction between 120 Mexican and 107 Mexican-American women, investigated the role of marianismo as a mediator between weight-related teasing and body satisfaction, and explored the relationship between marianismo, Partner Ideal Discrepancy, Ethnic Culture Ideal Discrepancy, Mainstream/American Culture Ideal Discrepancy, Perceived Weight-Related Criticism/Teasing, Relationship Support, Relationship Depth, and Relationship Conflict to overall body satisfaction. Results indicated Mexican-American women endorsed less overall body satisfaction than did their Mexican counterparts suggesting that Mexican American women may be more influenced by societal messages about thinness and beauty than are Mexican women. The findings also revealed a possible trend for marianismo as a mediator between weight-related criticism and body satisfaction. Marianismo and weight-related teasing were found to have a negative relationship with body satisfaction. Multiple regression analyses revealed that Partner Ideal and Mainstream/American Culture Ideal discrepancies accounted for significant variance in body satisfaction. Relationship Conflict accounted for a smaller but still significant amount of the variance in body satisfaction. Ethnic Culture Discrepancy, Relationship Support, and Relationship Depth were not significant predictors. These findings from this study suggest that both cultural variables and romantic relationship variables are related to the body image of Mexican American and Mexican women. These findings have important implications for the adaptation of current etiological models explaining body satisfaction among Mexican and Mexican-American women as well as highlighting the need to consider the role of both cultural and relationship variables in designing clinical interventions for Mexican American and Mexican women coping with body image concerns.

Currently, there is a clear gap in the missing data literature for three-level models.

To date, the literature has only focused on the theoretical and algorithmic work

required to implement three-level imputation using the joint model (JM) method of

imputation, leaving relatively no work done on fully conditional specication (FCS)

method. Moreover, the literature lacks any methodological evaluation of three-level

imputation. Thus, this thesis serves two purposes: (1) to develop an algorithm in

order to implement FCS in the context of a three-level model and (2) to evaluate

both imputation methods. The simulation investigated a random intercept model

under both 20% and 40% missing data rates. The ndings of this thesis suggest

that the estimates for both JM and FCS were largely unbiased, gave good coverage,

and produced similar results. The sole exception for both methods was the slope for

the level-3 variable, which was modestly biased. The bias exhibited by the methods

could be due to the small number of clusters used. This nding suggests that future

research ought to investigate and establish clear recommendations for the number of

clusters required by these imputation methods. To conclude, this thesis serves as a

preliminary start in tackling a much larger issue and gap in the current missing data

literature.

Internalizing symptoms are prevalent among adolescents, especially among Latinos, and can have negative consequences on health and development. Understanding the risk and protective factors leading to internalizing difficulties among Latino youth is critical. The current study sought to assess the effects of family risk and peer social rejection in the seventh grade on internalizing symptoms in the tenth grade, and the potential buffering effects of social support from family and from friends, among a sample of 749 Mexican American youth. Structural equation modeling was used to examine pathways from seventh grade family risk and peer social rejection to internalizing symptoms in the tenth grade. Perceived social support from family and perceived social support from friends were tested as moderators of these relations. Gender differences in these pathways were also assessed. Results showed that family risk did not predict tenth grade internalizing symptoms, but that peer social rejection predicted increased internalizing symptoms for girls. Furthermore, buffering effects were not confirmed; rather social support from both friends and family had no effect on the relation between family risk and internalizing symptoms, and high levels of social support from both sources amplified the effect of peer social rejection on internalizing symptoms. Secondary analyses suggested that at low levels of social support from both sources, peer social rejection predicted decreased internalizing symptoms for males. Limitations and implications for prevention and future research are discussed.

The first half-year of infancy represents a salient time in which emotion expression assumes a more psychological character as opposed to a predominantly physiological one. Although previous research has demonstrated the relations between early parenting and later emotional competencies, there has been less of a focus on differentiating positive and negative emotion expression across the early infancy period. Thus, the current study investigates the growth of positive and negative emotion expression across early infancy in a low-income, Mexican-American sample, and examines the development of emotion expression as a function of early maternal emotion socialization and prenatal stress. Participants included 322 mothers and their infants. Data were collected in participants' homes prenatally and when the infants were 12-, 18-, and 24-weeks old. Mothers were asked to interact with their infants in a semi-structured teaching task, and video-taped interactions of mother and infant behaviors were then coded. Data for mothers was collected at the prenatal and 12-week visits and data for infants was collected at the 12-, 18-, and 24-week visits. Prenatal stress was measured via two questionnaires (Daily Hassles Questionnaire and Perceived Stress Scale). Maternal socialization at 12 weeks was represented as a composite of four observational codes from the Coding Interactive Behavior coding system. Infant emotion expression was also globally rated across the 5-minute teaching task. Findings suggest that the normative development of emotion expression across early infancy is complex. Positive emotion expression may increase across the early infancy period whereas negative emotion expression decreases. Further, at 12 weeks, greater maternal emotion socialization relates to more infant positivity and less negativity, in line with current conceptualization of parenting. However, across time, greater early socialization predicted decreased positivity and was unrelated to negative emotion expression. Findings also suggest that prenatal stress does not relate to socialization efforts or to infant emotion expression. A better understanding of the nuanced development of positive and negative emotion development as a function of early parenting may have implications for early intervention and prevention in this high-risk population.