Browsing by Author "Davies, Patricia, committee member"
Now showing 1 - 13 of 13
Results Per Page
Sort Options
Item Open Access Assessment of sensation seeking personality type using behavioral and functional neuroimaging measures(Colorado State University. Libraries, 2020) DiCecco, Samuel M., author; Seger, Carol, advisor; Conner, Brad, advisor; Davies, Patricia, committee memberSensation seeking personality type, in which an individual has the propensity to engage in risky behaviors while searching for an optimal level of stimulation, is associated with a variety of negative health outcomes, such as higher rates of substance misuse, gambling, and self-harm. It is important to develop methods to identify those at higher risk of engaging in such health risk behaviors. Historically, sensation seeking has been primarily measured using self-report surveys. Providing additional measures of sensation seeking, such as through behavioral assessment or biomarkers, would aid our measurement of the sensation seeking personality type. The present work sought to create a new behavioral measure of sensation seeking personality type, the Sensation Seeking Dot Probe Task (SSDP), that measures an individual's attentional bias towards sensation seeking imagery. Further, the SSDP task was combined with functional Near Infrared Spectroscopy, which utilizes the spectral differences of hemoglobin in the brain to measure neural activity, to identify neural correlates of attention to sensation seeking imagery and relate them to the Sensation Seeking Personality Type scale. I hypothesized that the SSDP would be as effective in identifying sensation seeking as the self-report scale, and that attention to sensation seeking images would correlate with changes in neural activity in the prefrontal cortex and orbitofrontal cortex (regions associated with executive control and decision making) that would be greater in high sensation seeking individuals. While the SSDP did not find significant differences in accuracy or reaction time, the typical measures used in attentional bias dot-probe tasks, there was a significant difference in selection of sensation seeking imagery when paired with neutral control imagery. There were also significantly different changes in activity during sensation seeking congruent tasks in areas of the lateral prefrontal cortex for high sensation seeking individuals. These results suggest functional and behavioral differences measurable in high sensation seekers, and future tasks can use these findings to lead to a greater understanding of the personality type.Item Open Access Detecting error related negativity using EEG potentials generated during simulated brain computer interaction(Colorado State University. Libraries, 2014) Verlekar, Prathamesh, author; Anderson, Charles, advisor; Ruiz, Jaime, committee member; Davies, Patricia, committee memberError related negativity (ERN) is one of the components of the Event-Related Potential (ERP) observed during stimulus based tasks. In order to improve the performance of a brain computing interface (BCI) system, it is important to capture the ERN, classify the trials as correct or incorrect and feed this information back to the system. The objective of this study was to investigate techniques to detect presence of ERN in trials. In this thesis, features based on averaged ERP recordings were used to classify incorrect from correct actions. One feature selection technique coupled with four classification methods were used and compared in this work. Data were obtained from healthy subjects who performed an interaction experiment and the presence of ERN indicating incorrect responses was studied. Using suitable classifiers trained on data recorded earlier, the average recognition rate of correct and erroneous trials was reported and analyzed. The significance of selecting a subset of features to reduce the data dimensionality and to improve the classification performance was explored and discussed. We obtained success rates as high as 72% using a highly compact feature subset.Item Open Access Development and evaluation of Food friends get movin' with mighty moves™ : a physical activity program to prevent obesity in low-income preschoolers(Colorado State University. Libraries, 2007) Bellows, Laura Leigh, author; Jennifer Anderson, advisor; Auld, Garry, committee member; Kennedy, Catherine, committee member; Davies, Patricia, committee memberThe prevalence of overweight among preschool-aged children in the United States is increasing at an alarming rate. The preschool years provide an opportunity to establish healthful eating and physical activity behaviors which can lessen the growth of obesity. Unfortunately, preschoolers have been largely ignored when it comes to obesity prevention efforts. The overall objective of this project was to design, develop, and evaluate a physical activity program to compliment the Food Friends ® nutrition program in an effort to prevent overweight in young children. Food Friends Get Movin' with Mighty Moves™ is an 18 week program focusing on gross motor development, physical fitness, and physical activity in the classroom environment. This project utilized the steps of social marketing to develop the Mighty Moves™ program. Further, to enhance the likelihood that behavior change would occur, the Social Learning Theory was embedded within the social marketing framework. The Food Friends Get Movin' with Mighty Moves™ study was a randomized controlled trial of 3- to 5-year old children (n=201) enrolled in 8 Head Start centers in Colorado. On-site measures included height, weight, physical fitness (sit-ups, sit-n-reach, shuttle run, 3-minute run), and gross motor skill (Peabody Developmental Motor Scales) assessments. BMI, BMI z-score and BMI percentiles were calculated. Additionally, physical activity was assessed by pedometers over a 6-day timeframe (4 weekdays and 2 weekend days), and daily step counts were recorded by parents. Characteristics of the study population indicated a high prevalence of overweight, low physical activity levels, and average to below-average motor skills. The intervention did not have an effect on weight status but did improve gross motor skills and fitness levels. Lastly, no difference was found for physical activity by treatment. The success of Mighty Moves™ at increasing gross motor skills and physical fitness in preschoolers, in concert with the Food Friends® program's demonstrated ability to increase children's willingness to try new foods, has contributed to the establishment of healthful behaviors for proper growth and development in the early years. These behaviors serve as foundations to building healthy lifestyles, which may decrease the risk of overweight later in life.Item Open Access Examining the tip-of-the-tongue phenomenon with scalar judgments(Colorado State University. Libraries, 2023) Claxton, Alexander B., author; Cleary, Anne, advisor; Davalos, Deanna, committee member; Rhodes, Matthew, committee member; Davies, Patricia, committee memberThe Tip-of-the-Tongue (TOT) state, which is the feeling of being on the verge of retrieving a word that is as of yet unretrieved, occupies a space between a lack of recall and successful recall. Recent work has found that when someone experiences a TOT state they are more likely to attribute fluent characteristics to the sought after item. The present study sought to explore whether this TOT heuristic was driven by attribution of fluency and what, if any, relationship exists between the TOT heuristic and the subjective intensity of a given TOT state. Initial experiments were able to identify the TOT heuristic with both a binary and scalar TOT rating, but did not find any impact of objective fluency on the TOT heuristic. Follow-up experiments expanded on these findings by utilizing both a scalar (1 to 10 intensity rating) and binary (yes or no) TOT rating. A positive relationship between TOT magnitude ratings and the TOT heuristic was identified. This relationship was significant for both ratings of whether an item had been previously presented and font color ratings.Item Open Access Food selectivity and weight status in children with an Autism Spectrum Disorder (ASD)(Colorado State University. Libraries, 2014) Withrow-McDonald, Nicole A., author; Harris, Mary, advisor; Johnson, Susan L., advisor; Anderson, Jennifer, committee member; Davies, Patricia, committee memberTo view the abstract, please see the full text of the document.Item Open Access Generative topographic mapping of electroencephalography (EEG) data(Colorado State University. Libraries, 2014) Dantanarayana, Navini, author; Anderson, Charles, advisor; Ben-Hur, Asa, committee member; Davies, Patricia, committee memberGenerative Topographic Mapping (GTM) assumes that the features of high dimensional data can be described by a few variables (usually 1 or 2). Based on this assumption, the GTM trains unsupervised on the high dimensional data to find these variables from which the features can be generated. The variables can be used to represent and visualize the original data on a low dimensional space. Here, we have applied the GTM algorithm on Electroencephalography (EEG) signals in order to find a two dimensional representation for them. The 2-D representation can also be used to classify the EEG signals with P300 waves, an Event Related Potential (ERP) that occurs when the subject identifies a rare but expected stimulus. Furthermore, unsupervised feature learning capability of the GTM algorithm is investigated by providing EEG signals of different subjects and protocols. The results indicate that the algorithm successfully captures the feature variations in the data when generating the 2-D representation, therefore can be efficiently used as a powerful data visualization and analysis tool.Item Open Access Participation in early childhood educational environments for young children with and without developmental delays: a mixed methods study(Colorado State University. Libraries, 2014) Benjamin, Tanya Elizabeth, author; Khetani, Mary, advisor; Davies, Patricia, committee member; Lucas-Thompson, Rachel, committee memberChildren's participation in school-based activities is an important indicator of their inclusion. Prior studies have shown disparities in school participation between children with and without disabilities, but there is limited knowledge about whether these disparities are present during the early childhood period. The purpose of this concurrent transformative mixed methods study is three-fold: 1) to generate new knowledge about similarities and differences in how young children with and without developmental delays participate in daycare/preschool activities (in terms of their participation frequency, level of involvement, and parental desire for change), 2) to examine similarities and differences in perceived environmental supports for participation in daycare/preschool activities, and 3) to identify patterns in the strategies used by parents who want their child's participation to change. This study leverages the newly developed Young Children's Participation and Environment Measure (YC-PEM) to build new knowledge about young children's participation in a daycare/preschool environment. Study results suggest moderate to large disability group differences in young children's daycare/preschool participation and perceived environmental support for participation, even after controlling for the confounding effects of child gender, child age, and family income. Parents of young children with developmental delays, on average, report their children as less involved in daycare/preschool activities and perceive fewer supports for participation in their child's daycare/preschool environment. At the item level, significant disability group differences were found with respect to the child's frequency and level of involvement in daycare/preschool activities across all three daycare/preschool activities (i.e., group learning, socializing with friends, field trips and events). Significant disability group differences were also found in percent desire change for two of three activities (i.e., group learning, socializing with friends). Lastly, significant group differences on perceived environmental support for daycare/preschool participation were found for all but one environmental item (programs and services). Among parents who desired change in their child's participation in daycare/preschool activities, a desire for change was reported across multiple dimensions (frequency, level of involvement, broader variety). The most commonly reported parental strategies to improve participation in daycare/preschool activities pertained to childcare tasks and child peer groups, and these strategies were used irrespective of the type(s) of change that parents desired. In conclusion, the study findings suggest that 1) discrepancies in school participation between children with and without disabilities can be detected in the early childhood period and along multiple dimensions (frequency, level of involvement, parental desire for change); 2) there are wide range of perceived environmental barriers that may be appropriate intervention targets to minimize disparities in school participation for young children with developmental delays; 3) some, but not all, of the ten family accommodations that have been reported in prior literature are commonly used by parents to improve their young child's participation in a daycare/preschool setting. These study results, in turn, support the utility of the YC-PEM for use by stakeholders to 1) identify young children with participation restriction in an early childhood educational setting, 2) identify specific environmental barriers and supports impacting participation in this setting, and 3) anticipate the types of parental strategies that could be expanded upon by stakeholders to improve participation outcomes for young children experiencing participation restriction.Item Open Access Phases of systematic brain processing differentially relate to cognitive constructs of attention and executive function in typically-developing children: a latent variable analysis(Colorado State University. Libraries, 2017) Taylor, Brittany Kristine, author; Gavin, William, advisor; Davies, Patricia, committee member; Seger, Carol, committee member; Shomaker, Lauren, committee memberThe series of studies presented in this dissertation examines the complex interrelationships between brain measures, cognitive abilities, and simple behaviors in typically-developing children. Much recent research has been dedicated to understanding the interaction between neural processing and behaviors across development. However, the field continues to rely on simplistic statistical approaches (e.g., correlations, t tests, ANOVAs), which 1) are unable to simultaneously examine multiple interrelationships among variables of interest, and 2) are easily confounded by sources of measurement error. The result is weak relationships between brain and behavioral measures. In this series of studies, we progressively demonstrate how more sophisticated statistical approaches, namely structural equation modeling (SEM) techniques, can be utilized in order to improve researchers' ability to detect brain-behavior relationships in children. All three of the present studies utilize event-related potential (ERP) and behavioral data collected from a sample of typically-developing children ages of 7- to 13-years-old during two separate sessions. In Study 1, we explore the interrelationships between the E-wave component of an ERP, two trait behavioral measures of attentional processing, and simple reaction time (RT) measures during the ERP task. Whereas simple bivariate correlations indicated that the E-wave and RT only shared 7.9 – 9.6% of their variance, a latent variable approach using E-wave and trait attention measures successfully predicted 47.7% of the variance in RT. However, the predictive coefficient from brain-to-behavior was still weak (β = .23), suggesting that there may be neural influences in addition to the E-wave that contribute to the variance in RT. Thus, in Study 2 we elaborated on this model and explored whether the full time-course of an averaged ERP could be conceptualized as a sequence of phases that represents stimulus-to-response decision-making processes. Specifically, we tested a latent variable path model in which one ERP component predicted the next in chronological order, with the full stream of neural processing ultimately predicting RT during the task (N1 → P2 → N2 → P3 → E-wave → RT). Age served as a control variable on each phase of processing and on RT. Results indicated strong predictive relationships from one component to the next (β's = .59 - .86), with the full stream of processing significantly predicting RT (β = .45). The model was fully-mediated, underscoring the importance of the full time-course of the ERP for understanding behaviors during the task. In addition, there were significant age effects on the N2, P3, and RT latent variables (β =.28, -.48, & -.42 respectively). Given the nature of path analyses, the findings suggested that "age" was likely a multifaceted construct representing maturation within multiple domains of cognitive or motor functioning. Study 3 explored the differential relationships between two developmentally-sensitive cognitive constructs and each of the phases of neural processing, effectively replacing "age" with more substantive definitions of maturational effects in the model. The two cognitive constructs captured aspects of attention and executive function processing. Indeed, the findings indicated that each phase of neural processing was differentially influenced by each of the two cognitive constructs. The data suggested that children with better, more matured abilities within a specific cognitive domain tended to have smaller amplitude ERP components from the N1 through the P3, and larger amplitude E-wave components. Conceptually, children with more matured cognitive abilities were able to process the ERP task more efficiently (or with less effort), and engaged in greater anticipatory processing leading to the task behavior when compared to children with less matured cognitive abilities. Of note, the full model did still significantly predict RT during the task, and to a much greater extent than was found in Study 2 (β = .92). The series of investigations in this dissertation demonstrate the utility of SEM approaches for understanding brain-behavior relationships in typically-developing children. Namely, the studies showed that 1) latent variable approaches are helpful in reducing measurement error in ERP and behavioral data, which may impede the detection of brain-behavior relationships when using more simplistic statistical approaches; 2) conceptualizing the full time-course of an ERP preceding a task behavior is not only helpful, but necessary to successfully predict behaviors; and 3) we can further elucidate unique influences of maturation on neural processing within multiple cognitive domains when we embrace advanced statistical approaches like SEM. Implications of the findings and import to the field are discussed in the final chapter.Item Open Access Prosodic influence in face emotion perception: evidence from behavioral measures and functional near-infrared spectroscopy(Colorado State University. Libraries, 2017) Becker, Katherine M., author; Rojas, Donald C., advisor; Davies, Patricia, committee member; Troup, Lucy J., committee memberThe perception of another person's emotional state is formed by the intersection of simultaneously presented affective vocal and facial information. These two channels are highly effective in communicating emotion as either can do so independently. However, it is unclear how these modalities interact and influence perception when they are integrated. The current study sought to disentangle the roles of each modality by manipulating both the vocal and facial components of emotion perception. Voice stimuli were comprised of nonverbal affective vocalizations produced in either a happy, angry, or neutral prosody. Face images were created from morphed continua, composed to two end-point images, of one happy, and one angry face. These stimuli were presented independently and together to fully dissociate the unimodal and bimodal aspects of affect perception. These stimuli were combined in one hybrid block design paradigm which was used in a behavioral experiment and a functional near-infrared spectroscopy experiment. The results indicated that prosody does effect the perception of affective faces and this can be evidenced in both the behavioral and functional imaging data. Moreover, these data suggest that prosody is differentially represented in the brain in a valence specific way. Together, these findings provide strong support for the crucial role of prosody in affect perception.Item Open Access Reliability of TMS measurements of the motor cortex(Colorado State University. Libraries, 2010) Causer, Laurie, author; Malcolm, Matt P., advisor; Davies, Patricia, committee member; Seger, Carol A., committee memberBACKGROUND: Transcranial magnetic stimulation (TMS) was introduced in 1985 and has been used to study the human motor system through a variety of applications including single pulse, paired pulse and repetitive pulse stimulation parameters. Paired pulse TMS studies assess motor cortical excitability, in which the first (conditioning) stimulus (CS) modifies the response to the second (test) stimulus (TS) (Maeda, Gangitano, Thall, & Pascual-Leone, 2002). The time between pulses, or the interstimulus interval, is the distinguishing factor between the application of paired pulse TMS to investigate intracortical inhibition (ICI) or intracortical facilitation (ICF). Studies of cortical excitability using paired pulse TMS can provide novel insights into the pathophysiology of various neurological and psychiatric disorders (Maeda, et ah, 2002) and have begun to be utilized as outcome measures to document changes in cortical excitability in response to repetitive TMS. The stability of the muscle responses known as motor evoked potentials (MEPs) elicited in response to paired pulse stimulation has not been well documented in the literature to date. As such, the primary goal of this study was to establish the test-retest reliability of two paired pulse measures of the motor cortex, ICI and ICF, in two muscle representations; first dorsal interossei (FDI) and abductor pollicis brevis (APB). METHODS: Fifteen healthy individuals, age 19-37 years old, participated in two identical testing sessions held exactly one week apart from each other. Four different types of stimulation (CS, TS, 2ms, and 15ms) were delivered over the motor cortex 20 times in a random order. The corresponding MEPs were recorded and their size were documented using two common methods found in the literature; area under the curve and peak to peak amplitude. RESULTS: Reliability was determined using intra-class correlation coefficients (ICCs). Poor reliability was documented in both methods of analysis; whether twenty trials or ten trials were averaged, and even still after normalizing data, with ICCs ranging from (-.508 - .347). CONCLUSION: Additional studies investigating the test-retest reliability of paired pulse measures of the motor cortex need to be conducted to document the stability of MEPs. Potential sources of variation in MEPs size include electrode placement variation, stimulation intensity changes, coil placement variability, state of the overall nervous system, and the state of the individual muscle (contracted/relaxed). Until the reliability of paired pulse stimulation is established, researchers should use caution linking the changes in the size of MEPs in response to paired pulse stimulation to interventions, disease, or other external factors.Item Open Access Super tasters and mighty movers: extending The Food Friends® messages into early elementary school(Colorado State University. Libraries, 2013) D'Hooge, Anna, author; Bellows, Laura, advisor; Anderson, Jennifer, committee member; Davies, Patricia, committee memberThe prevalence of childhood obesity has been increasing over the last thirty years for preschool aged children, two to five years of age, as well as among early elementary aged children, six to eleven years of age. The epidemic nature of this problem has led to the creation of multiple programs and intervention targeted at preschoolers aimed at preventing these upward trends into early elementary school and adulthood. The preschool years are particularly important for the development of eating habits along with the development of gross motor skills. Behavior change has been seen within this age group following interventions, but retention of such behaviors as the children progress into kindergarten and first grade has not been as well documented. The overall purpose of this project was to develop "booster" programming for kindergarten and first grade classrooms that extends the messages from The Food Friends®, preschool nutrition and physical activity programs, into early elementary school in an effort to sustain behavior changes made in preschool. To ascertain the best method for implementing a program into the classrooms, surveys and interviews were conducted with a convenient sample of kindergarten and first grade teachers. Survey questions were mailed; follow-up telephone interviews were conducted with a subsample of respondents. Findings guided the development and implementation of the "booster" programming in kindergarten classes. Process evaluation surveys were conducted to assess the fidelity of program and guide the development of the second year of programming and modifications to Year 1. The main themes found from the formative surveys and interviews included: 1) nutrition was not a consistent lesson topic; 2) physical activity was left for gym class and/or recess; and 3) the need for nutrition and activity messages/lessons to be incorporated into academic subject areas. A 5 unit "booster" program, based on Social Cognitive Theory, was developed utilizing The Food Friends® characters and themes of 'Super Tasters' and 'Mighty Movers'. Classroom-based lessons, with accompanying posters and banners for the cafeteria and gym, were implemented in two schools from December 2011 to April 2012. Process evaluation surveys were conducted online with teachers after each unit for fidelity and overall impressions of lessons/activities; interviews were conducted one-on-one with Extension agents. Findings included: 1) all agreed that they enjoyed the "booster" program; 2) it was helpful to have an Extension agent come to the classroom; and 3) few completed lessons intended to be taught by classroom teachers. Appropriate modifications to Year 1's program guided the development of Year 2 programming, slated for implementation in 2012-13 school year. The efficacy of the "booster" programming on behaviors will be evaluated as part of a larger longitudinal study. The ability to resonate messages of trying new foods and being more active within kindergarten and first grade students will contribute to the establishment of healthful behaviors at a young age, building the foundation of lifelong healthy lifestyles.Item Open Access The test-retest reliability of the contingent negative variation (CNV) in children and adults before and after removing aberrant CNV segments(Colorado State University. Libraries, 2014) Cabral, Brittany Kristine, author; Gavin, William, advisor; Davies, Patricia, committee member; Fidler, Deborah, committee member; Seger, Carol, committee memberThe contingent negative variation (CNV) is a slow, negative drift in electroencephalographic potential that occurs between two stimuli. Researchers have examined the CNV and its embedded components, the O-wave and E-wave, in the study of development and dysfunction in attentional processing. However, few studies have tested the reliability of these components, and never in a paradigm with two visual stimuli or in children. The present study investigated the test-retest reliability of the visually-evoked CNV components in 58 children and 32 adults. The efficacy of a newly-developed procedure for reducing trial-to-trial variability in ERPs was also tested. Participants performed a visual Go-NoGo task while EEG data were recorded during two sessions scheduled one-to-two weeks apart. Developmental data agreed with previous literature such that children had significantly less negative CNV amplitudes than adults, though each component presented with a significant Group by Session interaction. Adult amplitudes became less negative from one session to the next, and children's data shifted in the opposite direction. Correlational analyses also indicated that developmental trends were present among children; amplitudes became more negative with increasing age. Reliability analyses revealed significantly lower indices than previous findings using auditory paradigms. Although children seemed to have higher reliability (r = .34 - .53) than adults (r = .05 - .58), analyses revealed no significant differences between these groups. The newly developed procedure for reducing variability did not significantly improve reliability, but it did significantly change the amplitude of the total CNV. Future investigations should further examine the efficacy of this new procedure in producing averaged ERPs. The data from the present study suggest that researchers and clinicians should be careful in interpreting visually-evoked CNV components. Changes noted over time through the course of development or intervention may largely be the result of normal fluctuations in brain processing. Further research is required to better understand what underlying mechanisms may be affecting the reliability of the CNV components, and how to improve the reliability through adjustments to data collection procedures and measurement techniques.Item Open Access Understanding the home food and activity environment of low-income, rural families with young children(Colorado State University. Libraries, 2014) Burdell, Alexandra Celeste, author; Bellows, Laura, advisor; Johnson, Susan L., advisor; Boles, Richard, committee member; Davies, Patricia, committee memberTo view the abstract, please see the full text of the document.