Browsing by Author "Diaz, Vanessa"
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- Fine-Grained Analyses of Multisensory Integration and Emerging Language in 24-Month-OldsNetto, Madeline (Virginia Tech, 2024-05)The Multisensory Assessment Protocol (MAAP) is a protocol that measures whether participants look at a synchronized audiovisual event more than an asynchronous audiovisual event or a distractor. It has been used in previous studies to show the relationship between multisensory integration and language in infancy and toddlerhood. For example, Bruce et al. (2022) found that performance on the MAAP in social conditions was predictive of vocabulary in 24-month-olds monolingual English learners. However, it was the collapsed looking-time data for each condition across six trials that yielded these results. Instead, this analysis used fine-grained measures to characterize attention changes over time. The preliminary findings showed that toddlers’ attention to the initial trials of social events, but the final trials of nonsocial events, was predictive of their vocabulary. The current study demonstrates that analyzing changes in attention throughout the protocol can lead to a better understanding of the relationship between multisensory integration and vocabulary.
- From Terrible Twos to Sassy Sixes: The Development of Vocabulary and Executive Functioning Across Early ChildhoodBruce, Madeleine D. (Virginia Tech, 2022-05-09)Early childhood marks a time when word learning is accompanied by rapid growth in the cognitive processes that underlie self-modulated and goal-directed behavior (i.e., executive functions (EF)). Although there is empirical evidence to support the association between EF and vocabulary development in childhood, inconsistent findings have been reported regarding the extent to which early EF abilities predict later vocabulary outcomes and vice versa. Thus, the first aim of the present study was to employ a stringent analytic approach to examining the longitudinal relations between EF and vocabulary across multiple waves in early childhood (i.e., at ages 2, 3, 4, and 6). Among the studies that have documented a link between children's early and later EF/vocabulary skills, the underlying mechanism(s) that can account for this association have yet to be identified. As such, the second and third aims of this study were to investigate children's private speech and visual attention skills as potential mediators of the hypothesized link between early and later EF/vocabulary. The results indicate that after controlling for maternal education, a unidirectional cross-lagged panel model best fit the data. That is, across all measurement waves, children's vocabulary scores at one timepoint were positively predictive of their EF performance at the following timepoint. Although no evidence of mediation was detected, a significant and novel association emerged between children's early vocabulary scores and their later private speech production. Moreover, this study was able to replicate the well-established link between visual attention and receptive vocabulary among a sample of older children.
- Hormones as “difference makers” in cognitive and socioemotional aging processesEbner, Natalie C.; Kamin, Hayley; Diaz, Vanessa; Cohen, Ronald A.; MacDonald, Kai (Frontiers, 2015-01-22)Aging is associated with well-recognized alterations in brain function, some of which are reflected in cognitive decline. While less appreciated, there is also considerable evidence of socioemotional changes later in life, some of which are beneficial. In this review, we examine age-related changes and individual differences in four neuroendocrine systems—cortisol, estrogen, testosterone, and oxytocin—as “difference makers” in these processes. This suite of interrelated hormonal systems actively coordinates regulatory processes in brain and behavior throughout development, and their level and function fluctuate during the aging process. Despite these facts, their specific impact in cognitive and socioemotional aging has received relatively limited study. It is known that chronically elevated levels of the stress hormone cortisol exert neurotoxic effects on the aging brain with negative impacts on cognition and socioemotional functioning. In contrast, the sex hormones estrogen and testosterone appear to have neuroprotective effects in cognitive aging, but may decrease prosociality. Higher levels of the neuropeptide oxytocin benefit socioemotional functioning, but little is known about the effects of oxytocin on cognition or about age-related changes in the oxytocin system. In this paper, we will review the role of these hormones in the context of cognitive and socioemotional aging. In particular, we address the aforementioned gap in the literature by: (1) examining both singular actions and interrelations of these four hormonal systems; (2) exploring their correlations and causal relationships with aspects of cognitive and socioemotional aging; and (3) considering multilevel internal and external influences on these hormone systems within the framework of explanatory pluralism. We conclude with a discussion of promising future research directions.
- Is There an Association between Executive Function and Receptive Vocabulary in Bilingual Children? A Longitudinal ExaminationDiaz, Vanessa; Borjas, Maria; Farrar, M. Jeffrey (MDPI, 2021-01-13)Dual language management has been proposed as the reason for bilingual children’s sometimes enhanced executive functioning (EF). We sought to identify the directionality of the relation between language proficiency and EF, using measures of receptive vocabulary, inhibitory control, and cognitive flexibility. Data were collected twice, a year apart, on 35- to 66.8-month-old bilingual (n = 41, M = 49.19 months) and monolingual preschool children (n = 37, M = 47.82 months). The longitudinal results revealed that while the monolingual children’s vocabulary at Time 1 predicted EF at Time 2, EF at Time 1 did not predict vocabulary at Time 2. In contrast, for bilingual children the relation was not present at all. The results were similar after the one-time analyses. The absence of relations between EF and language in bilinguals, while present in monolinguals, challenges the current conceptualization of the EF advantage in bilinguals, and emphasizes the need for more research on the development of bilingual children.
- Is variability appropriate? Encoding Variability and Transfer-Appropriate ProcessingSalan, Jefferson (Virginia Tech, 2020-05-22)Transfer-appropriate processing (TAP) proposes that retrieval success is based on the match between processing at encoding and retrieval. We propose that the processing described by TAP determines the contextual cues that are encoded with an event. At retrieval, the presence or absence of contextual cues matching the encoding cues will influence success. To implement these principles as a strategy to improve memory, the nature of future retrieval processing or cues must be known during encoding. As this is unlikely in real-world memory function, we propose that increased encoding variability – increasing the range of encoded cues – increases the likelihood of TAP when the retrieval scenario is unknown. The larger the set of encoded cues, the more likely those cues will recur during retrieval and therefore achieve TAP. Preliminary research in our lab (Diana, unpublished data) has found that increased encoding variability improves memory for item information in a novel retrieval context. To test whether this benefit to memory is due to the increased likelihood of TAP, the current experiment compared the effects of encoding variability under conditions that emphasize TAP to conditions that reduce TAP. We found main effects of encoding variability and TAP, but no interaction between the two. Planned comparisons between high and low variability encoding contexts within matching and non-matching retrieval contexts did not produce a significant difference between high and low variability when encoding-retrieval processing matched. We conclude that further studies are necessary to determine whether encoding variability has mechanisms that benefit memory beyond TAP.
- The Maternal Force Awakens Emerging Fear Reactivity and Regulation: Preliminary Results from the Baby JEDI StudyPhillips, Jennifer Julia (Virginia Tech, 2024-05-17)Fear is an adaptive emotion that typically increases across infancy to help keep infant exploration in check. Too much fear, however, can become maladaptive and lead to psychopathology later in childhood. Thus, it is important to understand how both fear reactivity and regulation develop early in life in order to identify at-risk children early on. Maternal factors, such as parenting behaviors and personality, are associated with both fear reactivity and regulation, but results have been mixed, possibly due to a trait-based approach to assessing maternal personality. The goal of my dissertation was to examine the growth trajectories of fear reactivity and regulation across infancy and toddlerhood both unconditionally and within the contexts of maternal parenting and personality functioning. Infants and mothers were assessed when infants were 10-months (n = 48), 14-months (n = 42), and 18-months (n = 34) old. At each age, infant fear reactivity was assessed using behavioral coding during the Laboratory Temperament Assessment Battery fear tasks and infant fear regulation was examined via respiratory sinus arrhythmia reactivity during the fear tasks. At 10- and 14-months, maternal parenting behaviors were coded during an interaction task and maternal personality functioning was assessed via maternal self-report. Hierarchical linear modeling demonstrated that maternal personality functioning moderated the association between maternal affect and infant fear reactivity growth and maternal personality functioning moderated the association between maternal directiveness and infant fear regulation growth. These results aid in the understanding of how maternal factors relate to infant fear development.
- Parenting Behaviors Influence Children’s Mathematical Skills: Examining Potential Mediating and Moderating Roles of Child Executive FunctionDíaz Benítez, Vanessa P. (Virginia Tech, 2023-11-09)Parenting sets up the characteristics of the environment in which development takes place, making it a major predictor of most developmental outcomes, including academic skills. Much research has demonstrated that parenting behaviors influence math performance, however, the mechanisms and conditions under which this association takes place remain unclear. My thesis project assessed how child executive functions (EFs) influence the effects of middle childhood parenting on adolescents’ math skills. 77 mother-child dyads from Blacksburg contributed data in two different occasions: during the first visit (child age=9), maternal parenting behaviors (supportive and non-supportive), and child EF were assessed via questionnaires, behavioral coding, and a battery of EF tasks; during the second visit (child age=14), children’s math skills were assessed using a standardized test of achievement. Regression analyses revealed a direct effect of a composite measure of non-supportive parenting during middle childhood on adolescents’ math performance. Furthermore, EF did not mediate or moderate the effect of parenting on math skills, when using composite measures of parenting. However, when the parenting behaviors were assessed individually, maternal facilitation of attention, maternal expressive encouragement, and maternal minimizing reactions had indirect effects on adolescents’ math skills via EFs; specifically, working memory and inhibitory control were significant mediators. Furthermore, child cognitive flexibility moderated the effect of maternal distress reactions on adolescents’ math skills, but only when the levels of cognitive flexibility are considerably low.