Browsing by Author "Seger, Carol, committee member"
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Item Open Access Educational attainment polygenic scores, socioeconomic factors, and resting-state functional connectivity in children and adolescents(Colorado State University. Libraries, 2024) Hansen, Melissa, author; Merz, Emily, advisor; Thomas, Michael, committee member; Seger, Carol, committee member; Riggs, Nathan, committee memberSocioeconomic factors, such as family income and parental education, have been associated with resting-state functional connectivity (rsFC) in networks responsible for executive function in children and adolescents. Yet, children's socioeconomic context interacts with the genetics they inherit from their parents, and few studies of socioeconomic context and rsFC in children have considered genetics. Polygenic scores for educational attainment (PGS-EA) derived from genome-wide association studies (GWAS) reflect genetic predisposition to educational attainment. Yet, no studies have examined the associations between PGS-EA and rsFC. The goal of this study was to investigate how socioeconomic factors and PGS-EA jointly predict rsFC in neural networks associated with executive function, including the central executive (CEN), dorsal attention (DAN), salience (SN), and default mode networks (DMN) in children and adolescents. Participants are typically-developing 3- to 21-year-olds (N = 245, 51% female) from the previously-collected Pediatric Imaging, Neurocognition, and Genetics (PING) study. PGS-EA were computed based on the EA3 GWAS of educational attainment. Resting- state fMRI data were acquired, and system-level rsFC was computed. Findings indicated that family income was inversely associated with rsFC in the SN, while PGS-EA was positively associated with rsFC in the CEN. There were family income-by-age interactions for rsFC in the CEN and DAN, such that age was positively associated with rsFC in the CEN and DAN for children from higher income families and inversely associated with rsFC in the CEN for children from lower income families. These findings help to elucidate the independent genetic and socioeconomic contributions to connectivity in intrinsic functional neural networks underlying executive function.Item Open Access Helping humans and agents avoid undesirable consequences with models of intervention(Colorado State University. Libraries, 2021) Weerawardhana, Sachini Situmini, author; Whitley, Darrell, advisor; Ray, Indrajit, committee member; Pallickara, Sangmi, committee member; Ortega, Francisco, committee member; Seger, Carol, committee memberWhen working in an unfamiliar online environment, it can be helpful to have an observer that can intervene and guide a user toward a desirable outcome while avoiding undesirable outcomes or frustration. The Intervention Problem is deciding when to intervene in order to help a user. The Intervention Problem is similar to, but distinct from, Plan Recognition because the observer must not only recognize the intended goals of a user but also when to intervene to help the user when necessary. In this dissertation, we formalize a family of intervention problems to address two sub-problems: (1) The Intervention Recognition Problem, and (2) The Intervention Recovery Problem. The Intervention Recognition Problem views the environment as a state transition system where an agent (or a human user), in order to achieve a desirable outcome, executes actions that change the environment from one state to the next. Some states in the environment are undesirable and the user does not have the ability to recognize them and the intervening agent wants to help the user in the environment avoid the undesirable state. In this dissertation, we model the environment as a classical planning problem and discuss three intervention models to address the Intervention Recognition Problem. The three models address different dimensions of the Intervention Recognition Problem, specifically the actors in the environment, information hidden from the intervening agent, type of observations and noise in the observations. The first model: Intervention by Recognizing Actions Enabling Multiple Undesirable Consequences, is motivated by a study where we observed how home computer users practice cyber-security and take action to unwittingly put their online safety at risk. The model is defined for an environment where three agents: the user, the attacker and the intervening agent are present. The intervening agent helps the user reach a desirable goal that is hidden from the intervening agent by recognizing critical actions that enable multiple undesirable consequences. We view the problem of recognizing critical actions as a multi-factor decision problem of three domain-independent metrics: certainty, timeliness and desirability. The three metrics simulate the trade-off between the safety and freedom of the observed agent when selecting critical actions to intervene. The second model: Intervention as Classical Planning, we model scenarios where the intervening agent observes a user and a competitor attempting to achieve different goals in the same environment. A key difference in this model compared to the first model is that the intervening agent is aware of the user's desirable goal and the undesirable state. The intervening agent exploits the classical planning representation of the environment and uses automated planning to project the possible outcomes in the environment exactly and approximately. To recognize when intervention is required, the observer analyzes the plan suffixes leading to the user's desirable goal and the undesirable state and learns the differences between the plans that achieve the desirable goal and plans that achieve the undesirable state using machine learning. Similar to the first model, learning the differences between the safe and unsafe plans allows the intervening agent to balance specific actions with those that are necessary for the user to allow some freedom. The third model: Human-aware Intervention, we assume that the user is a human solving a cognitively engaging planning task. When human users plan, unlike an automated planner, they do not have the ability to use heuristics to search for the best solution. They often make mistakes and spend time exploring the search space of the planning problem. The complication this adds to the Intervention Recognition Problem is that deciding to intervene by analyzing plan suffixes generated by an automated planner is no longer feasible. Using a cognitively engaging puzzle solving task (Rush Hour) we study how human users solve the puzzle as a planning task and develop the Human-aware Intervention model combining automated planning and machine learning. The intervening agent uses a domain specific feature set more appropriate for human behavior to decide in real time whether to intervene the human user. Our experiments using the benchmark planning domains and human subject studies show that the three intervention recognition models out performs existing plan recognition algorithms in predicting when intervention is required. Our solution to address the Intervention Recovery Problem goes beyond the typical preventative measures to help the human user recover from intervention. We propose the Interactive Human-aware Intervention where a human user solves a cognitively engaging planning task with the assistance of an agent that implements the Human-aware Intervention. The Interactive Human-aware Intervention is different from typical preventive measures where the agent executes actions to modify the domain such that the undesirable plan can not progress (e.g., block an action). Our approach interactively guides the human user toward the solution to the planning task by revealing information about the remaining planning task. We evaluate the Interactive Human-aware Intervention using both subjective and objective measures in a human subject study.Item Open Access Immediate effects of training with musical mnemonics on verbal memory in children(Colorado State University. Libraries, 2016) Knott, David, author; LaGasse, Blythe, advisor; Knight, Andrew, advisor; Seger, Carol, committee memberThe purpose of this study was to compare the effects of musical mnemonics versus spoken word in training verbal memory in children. A randomized control trial of typically-developing 9-11 year old children was conducted using the Rey Auditory Verbal Learning Test (RAVLT), a test measuring a participant’s ability to recall a list of 15 words over multiple exposures. Members of the group that listened to words sung to them recalled an average of 20% more words after listening to and recalling an interference list than members of the control group that listened to the same words spoken. This difference persisted, though slightly smaller (17%) when participants recalled words after a 15-minute waiting period. Group participants who listened to words sung demonstrated a higher incidence of words recalled in correct serial order. Potential contributions of musical mnemonics during the learning phase were also considered. While key findings were statistically significant, other examples of improved performance for participants who listened to words sung were below the level of significance. At times large standard deviations and varied performance across tasks may suggest these performance effects are susceptible to individual differences, or that heterogeneity of cognitive functioning levels was represented in the sample. These findings suggest that musical mnemonic training may be more effective than rehearsal with spoken words in verbal memory learning tasks in 9-11 year olds.Item Open Access Phase-locking of gamma and beta in an auditory EEG paradigm and their relationship to self-reported sensory sensitivities(Colorado State University. Libraries, 2013) Phares-Zook, Kelly P., author; Davies, Patricia, advisor; Gavin, William, committee member; Atler, Karen, committee member; Seger, Carol, committee memberPhase-locking factor (PLF), one way to analyze electroencephalography (EEG) data, is the consistency of the brain's response in particular frequency bands to stimuli across multiple trials. Studies in the past have correlated PLF of different brainwave frequencies to behaviors; however, none have looked at the correlation to sensory sensitivities. The objective of the present study was to examine the relationship between PLF and behavioral measures in neurotypical adults. The participants were 38 neurotypical adults aged 18-25. This study involved an auditory paradigm in which three series of eight tones each were presented to the participant while he or she watched a movie. The first series presented eight tones that were identical, the second series presented a deviant tone in the 4th position with the other seven tones identical to the tones presented in the first series, and the third series had a deviant tone presented in the 5th position with the other 7 tones identical to the tones in the first series. These series of tones were presented in pseudorandom fashion while the participants' brainwaves were recorded with an EEG system. To examine the relationship between the consistency of the brain's response to these tones and sensory sensitivities, the participants filled out the Adult/Adolescent Sensory Profile (AASP). It was hypothesized that the PLF value at the onset of the first tone in the series of tones with no deviants would be greater than the subsequent tones in the same series. In the series of tones with no deviants, PLF for gamma (30-50 Hz) for tone 1 was higher than all but one of the PLF responses to subsequent tones. PLF in the beta region (18-30 Hz) in response to tone 1 was higher than the PLF response to all subsequent tones in the series with no deviants. Some, but not all, of these findings reached significance. It was also hypothesized that PLF at the onset of a deviant tone would be greater than PLF at the onset of non-deviant tones 2-8 in the same series. For the series of tones with a deviant in the 4th position, gamma increased from tone 3 to tone 4 for central electrode sites and decreased for frontal electrode sites, although none reached significance. For the series of tones with the deviant in the 5th position, PLF for gamma at tone 5 was greater than at tone 4 for 4/6 electrodes. For the series of tones with a deviant in the 4th position, PLF in the beta region increased from tone 4 to tone 5. For the series of tones with a deviant in the 5th position, PLF in the beta region increased from tone 4 to tone 5 for half of the electrode sites. It was hypothesized that PLF in response to the first tone of a series would not be significantly different from PLF in response to a deviant tone of the same series. PLF in the gamma region did not ever significantly differ from the first tone to the deviant tone. PLF in the beta region did not significantly differ from tone 1 to tone 4 in the series of tones with the deviant in the 4th position, but PLF for tone 1 was significantly higher than PLF for tone 5 for 2/6 electrode sites during the series of tones with the deviant in the 5th position. Lastly, it was hypothesized that individuals who have higher PLF will demonstrate low neurological thresholds as measured by the AASP. Spearman Rho correlations revealed that nearly all significant findings found between PLF and scores on the AASP were positive correlations. Results indicated that better phase-locking in the brain correlates positively with increased sensory sensitivities, as demonstrated by the AASP. Additionally, this study supports prior research indicating that a decrease in PLF does occur from tone 1 to tone 2 when the tones are identical, but questions whether PLF reflects habituation that may occur in response to three or more of the same stimuli.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 Sensation seeking, impulsivity, and Big Five personality factors as predictors of risky behavior following concussion(Colorado State University. Libraries, 2020) Gardner, Megan M., author; Conner, Bradley T., advisor; Seger, Carol, committee member; Stephens, Jaclyn, committee memberSports-related concussion is a growing public health concern. With 30-50% of concussions remaining undiagnosed for a variety of reasons, it is crucial to identify risk factors and establish appropriate prevention and harm reduction strategies to prevent the risk of multiple concussions. Few studies have investigated personality factors as predictors of concussion and continued participation following an initial injury. However, research has concluded that personality likely plays a role in symptom reporting and post-injury behaviors that may put one at risk of additional injury and premature return to play. Most research on personality and health risk behaviors has focused on substance use, gambling, and criminal behavior, with little research done on personality, risky sports, and injury. The limited work in this area has concluded that the personality construct of sensation seeking is predictive of engagement in sports that have an increased risk for injury, while other constructs like impulsivity, are more predictive of injury once already participating in risky sports. The Big Five factors of personality differentially predict injury during sport such that openness to experience and extraversion predict risk-taking overall, while low levels of neuroticism and low levels of conscientiousness predict risky behavior during sport to different degrees depending on the sport studied. The current study found that sensation seeking dimensions, experience seeking and risk seeking, were positively associated with returning to play more quickly than others in the sample. Further, both of these dimensions were negatively predictive of use of protective behavioral strategies against incurring sports-related concussion. Risk seeking, attentional impulsivity, motor impulsivity, and non-planning impulsivity were found to be positively predictive of likelihood of reporting repeat sports-related concussions. Regarding the Big Five, conscientiousness was associated with taking longer to return to play, more protective behavioral strategy use, and a lower likelihood of reporting more than 1 sports-related concussion. These findings may be used in implementing individualized targeted prevention and intervention efforts for athletes. Future work should investigate the mechanisms underlying these relations, as well as include additional sports-related concussion risk factors.Item Open Access Socioeconomic inequality, amygdala and ventral striatal connectivity, and affective outcomes in children and adolescents(Colorado State University. Libraries, 2023) Strack, Jordan, author; Merz, Emily, advisor; Thomas, Michael, committee member; Seger, Carol, committee member; Lucas-Thompson, Rachel, committee memberSocioeconomic disadvantage has been significantly associated with an increased risk for internalizing problems in children and adolescents. The neural mechanisms underlying these associations, however, are not well understood. Differences in connectivity of the amygdala and ventral striatum with the prefrontal cortex (PFC) may play an important role in these mechanisms. The goals of this study were to examine (1) the associations among socioeconomic factors, amygdala and ventral striatal resting-state functional connectivity (rsFC), and emotional outcomes in children and adolescents, (2) sex differences in associations between socioeconomic factors and amygdala and ventral striatal rsFC, and (3) interactions between socioeconomic factors and familial/genetic risk for anxiety/depression in predicting amygdala and ventral striatal rsFC. Participants were typically-developing 3- to 20-year-olds (50% male, N = 590) from the Pediatric Imaging, Neurocognition, and Genetics (PING) study (Jernigan et al., 2016). Resting-state fMRI, socioeconomic (family income, parental education), and self-reported positive and negative affect data were collected. Measures of familial and genetic risk for anxiety/depression were family history of anxiety/depression and genome-wide polygenic risk scores for major depressive disorder (PRS-MDD), respectively. Whole-brain, seed-based functional connectivity analyses were conducted with the ventral striatum and the amygdala as seeds. Findings indicated significant interactions between socioeconomic factors and PRS-MDD for amygdala rsFC with the frontopolar cortex. Positive and negative affect were associated with amygdala and ventral striatum rsFC with various brain regions. Associations between socioeconomic factors and amygdala and ventral striatal rsFC and sex differences were not significant. These findings can be applied to informing the design of more effective prevention and intervention strategies to facilitate healthy emotional development.Item Open Access Systematic review of therapeutic interventions in occupational therapy for children with traumatic brain injury(Colorado State University. Libraries, 2010) Ferland, Erik Richard, author; Sample, Pat, advisor; Greene, David, committee member; Seger, Carol, committee memberObjective: The aim of this study was to conduct a systematic evidence-based search and review of the published literature pertaining to occupational therapy interventions for children with traumatic brain injuries. Data sources: The databases searched included PsychINFO (EBSCOhost), Academic Search Premier (EBSCOhost), CINAHL (EBSCOhost) and PsycARTICLES (EBSCOhost) as well as the reference lists of articles found. Search terms: Whole words included brain, head. Wild card searches included child*, injur*, p?ediat*, rehab*, interven*, traum*, occupation*, therap*. Inclusion criteria for research articles: The participants must be children and youth with traumatic brain injuries (TBI) sustained from birth -2 1 years old; the intervention must be an associated occupational therapy intervention; the study must include between groups designs, with either quasi-experimental or randomized experimental design, and within subject single subject designs. Data interpretation: The author assessed each article against a rubric that looked at the quality various aspects of the study (e.g. design, methods, and outcome variables). Results: The researcher analyzed six articles with a total of 39 children with TBI. Three articles researched restrain therapy, one researched Lycra-based splints, one researched an antecedent behavioral intervention, and one discussed a problem solving intervention for families of children with TBI. Conclusion: The researchers found positive effects for the CIT interventions, the antecedent behavioral intervention and the family problem-solving intervention. The researchers who looked at the Lycra splinting found mixed results that were inconclusive.Item Open Access The experience of novelty: another dimension to subjective memory experience?(Colorado State University. Libraries, 2014) Staley, Shelly, author; Cleary, Anne, advisor; Seger, Carol, committee member; Hoke, Kim, committee memberSubjective experiences of memory (e.g., feelings of familiarity) have been a topic of much research. Though novelty might be considered a manifestation of memory (insofar as some form of memory for the past is required in order for novelty recognition or detection to occur), subjective experiences of novelty have largely been ignored in the current memory literature. The present study used a rating scale to measure the subjective feeling of novelty. One goal was to investigate potential mechanisms of feelings of novelty. Another was to determine how feelings of novelty relate to feelings of familiarity; for example, many models assume that novelty is simply the inverse of familiarity. Two experiments reported here examined if this presumed relationship between familiarity and novelty is an accurate assumption. In one experiment, subjects viewed words in a study list and then were tested on cues that potentially shared orthographic features with the study words while duration of cue-prime exposure and cue-match-priming effects were observed. In another, subjects were tested after having repeated the test cues aloud either once or 30 times. Both experiments compared a familiarity rating scale with a novelty rating scale. No effects of duration of exposure (either through priming in Experiments 1 and 2 or repetitions in Experiment 3) were observed, helping to rule out several potential mechanisms of feelings of novelty. Differences in how familiarity ratings and novelty ratings responded to the experimental manipulations were found in both experiments, suggesting that the sense of novelty is not simply the inverse of familiarity.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 Validating a points-based effort expenditure for rewards task(Colorado State University. Libraries, 2024) Sturm, Emily T., author; Thomas, Michael L., advisor; Seger, Carol, committee member; Stephens, Jaclyn, committee member; Tompkins, Sara Anne, committee memberInvalid performance on neurocognitive tests due to lack of effort expenditure is a concern for researchers and clinicians. Performance validity tests determine when adequate effort has been expended, but they fail to differentiate between subcomponents of effort that may be responsible for poor performance. The Effort Expenditure for Reward Task (EEfRT) is a task that provides separate measurements of reward processing and valuation constructs which could be informative as performance validity indicators. However, previous versions of the EEfRT use monetary performance-based rewards to investigate the expected value of effort, which can be problematic due to the influence of socio-economic factors and potential to systematically disadvantage participants with neurocognitive disorders. This study first aimed to examine the construct validity, specifically, the construct representation of a points-based version of the EEfRT online and in-person. The second aim of this study, which is exploratory, is to characterize patterns in embedded performance validity test performance obtained for separate neurocognitive measures as well as the EEfRT, thereby informing nomothetic span, or patterns of significant relations across measures of effort. This aim assessed whether the scores from the EEfRT indicate performance validity in other domains. Online participants (n = 342) from Prolific.com for the online sample and in-person participants (n = 27) were recruited via advertisements. Participants completed a battery including the EEfRT along with three working memory tasks, two executive functioning tasks, and one reward learning task. Results of regression analyses showed that, as hypothesized, both online and in-person participants chose hard tasks significantly more often at higher reward levels and at higher probability levels. However, contrary to expectations, a significant interaction between reward and group showed that points were more motivating in the online setting compared to in-person. Exploratory latent profile analysis revealed no clear pattern in embedded performance validity tests within the EEfRT or across other tasks. The results of this study suggest that a points-based version of the EEfRT is potentially valid for measuring effort-based decision making, but more research is needed before it can be called an objective measure of effort in the context of validating performance on cognitive tests.Item Open Access What in your right mind would make you do that?? Proximate and ultimate mechanisms of plasticity in mating strategies by the Trinidadian guppy (Poecilia reticulata)(Colorado State University. Libraries, 2020) Dolphin, Kimberly, author; Hoke, Kim, advisor; Mueller, Rachel, committee member; Seger, Carol, committee member; Ghalambor, Cameron, committee memberAll animals must make decisions every day and often these decisions are directly linked to fitness outcomes, meaning better decisions are expected to be associated with higher fitness. Rapid decisions between alternative strategies allow animals to behave more appropriately for their environment. Thus, selection will shape not only how animals will respond to cues at different timescales, but also what cues they respond to at different timescales. Neural substrates of decisions are a vital component for our understanding of how experiences on different timescale influence decision-making strategies. The sensitivity of sensory systems to specific cues is tuned by genetics and then subsequently refined through developmental neural plasticity. The goal of this dissertation is to fill in gaps in understanding how experiences across multiple timescales influence neural mechanisms and behavioral strategies. I chose to address this question with the alternative mating strategies of male Trinidadian guppies (Poecilia reticulata), a sexually dimorphic tropical fish native to the island of Trinidad. In chapter two we compared how ancestral predation pressures influenced sensitivity to developmental exposure to predator cues and how those two timescales interacted to shape activity and reproductive behaviors when males were in different social contexts. Evolutionary history shaped how developmental contexts influence the resulting behavioral phenotypes across multiple acute contexts. However, the influence of experiences across timescales were not consistent between behaviors. We then extended our study further in chapter three to investigate how developmental experiences with conspecifics influenced males' later abilities not only to respond to virgin and recently mated females, but also to refine mating strategies in response to the female behaviors over multiple exposures. Social experiences during developmental timescales also had distinct influences on the expression of the two reproductive strategies in chapter three. We showed that males modulated and refined mating strategies relatively independently of each other in relationship to their rearing experiences. We concluded with an investigatory probe into the cellular identities of neurons that are responding to a reproductive context in chapter four using a phosphoTRAP RNA-seq protocol. Chapter four provides evidence that several neuromodulatory pathways respond to cues in a reproductive context, which could point to constraints on evolution. In sum, this dissertation used an integrative approach to understand how experiences across multiple timescales influence decisions. We bridged several fields that can help provide insight into the evolution of decision-making processes and allow us to make future hypotheses about influences of multiple experiences with complex cues.